CN103714432A - Method for predicating biomass of submerged plant by establishing growth simulation model - Google Patents

Abstract

A method for predicating biomass of a submerged plant by establishing a growth simulation model comprises the following steps that firstly, a relevant dynamic mass conservation equation is obtained according to the relation among algae, organic carbon, phosphorus, nitrogen and dissolved oxygen in a lake; secondly, a relevant dynamic mass conservation equation is obtained according to the relation among the stem and root of the submerged plant and aerophyte growing around the stem; thirdly, coupling is carried out on a water quality module and a submerged plant module, and the functions of the submerged plant are added to the relevant dynamic mass conservation equations; fourthly, each model time step differential equation is solved, the biomass of the submerged plant is finally obtained, and the biomass predicating of the submerged plant is finished.

Description

A kind of method of predicting the biomass of submerged plant by building growth simulation model

Technical field

The invention belongs to a kind of method based on biomass of submerged plant in growth simulation model prediction water body, particularly a kind of method that is applicable to predict small-sized submerged plants in shallow water lake biomass.

Background technology

Submerged plant refers to that the heavy aquatic work of plant, root are born in the hydrophyte in substrate in most of life cycle.Submerged plant is as one of important component part of lake ecosystem and main primary producer, its circulation to the matter and energy of lake ecosystem plays an important role, water nutrition system is had to important regulating action, particularly submerged plant has occupied the main interface of the water and sediment in lake, and lake yield-power and lake ecosystem are had to very important impact.It is most important to the reparation of eutrophic lake as main aquatic vegetation that submerged plant is take in recovery, therefore, for reaching the object of revegetation, is also necessary to build some models with prediction vegetation growth tendency under various conditions except many real works.

Model about submerged plant can be divided into distributed model and Biomass Models.Distributed model mainly lays particular emphasis on distribution probability, the maximum distribution degree of depth and the coverage rate of analyzing submerged plant, but has ignored the amount of submerged plant.On the other hand, Biomass Models, comprises growth simulation model and holistic model, the development of pre-measuring plants from biomass.Holistic model Consideration is less, accuracy is poor, and growth simulation model is by a large amount of detailed submerged plant physiological data of input and the environmental data of every day, every day or the seasonal growth trend that can more effectively predict aquatic macrophyte, provide more scientific and reasonable reference data and suggestion to eutrophic lake submerged plant recovery project.

Summary of the invention

The object of the invention is, a kind of technical method that is applicable to predict small-sized submerged plants in shallow water lake biomass based on growth simulation model is provided, for predicting submerged vegetation growth tendency under various conditions.

Technical scheme of the present invention is as follows:

A method of predicting the biomass of submerged plant by building growth simulation model, is characterized in that step is as follows:

(1) use analytical instrument of water quality to obtain the data of algae in lake, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, according to the relation between algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO in lake, obtain relevant dynamical mass conservation equation, i.e. water quality module;

(2), according to the stem of submerged plant, root be grown in the relation between the epiphyte of stem, obtain relevant dynamical mass conservation equation, i.e. submerged plant module;

(3) water quality module and submerged plant module are coupled, relevant dynamical mass conservation equation adds the effect of submerged plant;

(4) to each model time step differential equation, finally obtain the biomass of submerged plant, complete the prediction of biomass of submerged plant.

A method of predicting the biomass of submerged plant by building growth simulation model, is characterized in that step is as follows:

(1) use analytical instrument of water quality to obtain the data of algae in lake, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, according to the relation between algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO in lake, obtain relevant dynamical mass conservation equation, i.e. water quality module;

(2), according to the stem of submerged plant, root be grown in the relation between the epiphyte of stem, obtain relevant dynamical mass conservation equation, i.e. submerged plant module;

(3) water quality module and submerged plant module are coupled, relevant dynamical mass conservation equation adds the effect of submerged plant;

Described water quality module in water body water-quality guideline (DO, TP, PO ₄ ^3--P, TN, NO ₃ ^--N, NH ₄ ⁺-N, Chla) carry out dynamic similation, for providing illumination, temperature, nutriment and other, submerged plant forces function;

Described submerged plant module is described submerged plant growth and decomposition; Submerged plant module comprises 3 state variables: stem (biomass in water column), root (biomass in substrate) and epiphyte (growing in the plant of submerged plant leaf table); Stem consumes the nutriment in water body and consumes the nutriment in substrate by root; Epiphyte absorbs the nutriment in water body; Root and substrate exchange nutriment.The stem of submerged plant, root and the epiphytic dynamical mass conservation equation that is grown in stem are:

$\frac{\∂\left(\mathrm{RPS}\right)}{\∂t}=[(1-F_{\mathrm{PRPR}})\·P_{\mathrm{RPS}}-R_{\mathrm{RPS}}-L_{\mathrm{RPS}}]\·\mathrm{RPS}+{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\∂\left(\mathrm{RPR}\right)}{\∂t}=F_{\mathrm{PRPR}}\·P_{\mathrm{RPS}}\·\mathrm{RPS}-(R_{\mathrm{RPR}}+L_{\mathrm{RPR}})\·\mathrm{RPR}-{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\∂\left(\mathrm{RPE}\right)}{\∂t}=(P_{\mathrm{RPE}}-R_{\mathrm{RPE}}-L_{\mathrm{RPE}})\·\mathrm{RPE}$

$\frac{\∂\left(\mathrm{RPD}\right)}{\∂t}=F_{\mathrm{RPSD}}\·L_{\mathrm{RPS}}\·\mathrm{RPS}-L_{\mathrm{RPD}}\·\mathrm{RPD}$

P _RPS＝PM _RPS·min(f(N) _RPS，f(P) _RPS)·f(I) _RPS·f(T) _RPS

$f{\left(I\right)}_{\mathrm{RPS}}=\frac{2.718}{\mathrm{Kess}\·\mathrm{HRPS}}\left(\exp (-\frac{I_o}{I_{\mathrm{sso}}}\·\exp (-\mathrm{Kess}\·H)\right)-\exp (-\frac{I_o}{I_{\mathrm{sso}}}\·\exp (-\mathrm{Kess}\·(H-\mathrm{HRPS}))$

${f\left(N\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\·({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}{{\mathrm{KHN}}_{\mathrm{RPS}}+{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\·({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}$

${f\left(P\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\·{\mathrm{PO}}_{4}B}{{\mathrm{KHP}}_{\mathrm{RPS}}+{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\·{\mathrm{PO}}_{4}B}$

${f\left(T\right)}_{\mathrm{RPS}}=\left\{\begin{array}{cc}\exp (-\mathrm{KTP}{1}_{\mathrm{RPS}}\·{[T-{\mathrm{TP}1}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\≤{\mathrm{TP}1}_{\mathrm{RPS}}\\ 1,& \mathrm{if}{\mathrm{TP}1}_{\mathrm{RPS}}\≤T\≤{\mathrm{TP}2}_{\mathrm{RPS}}\\ \exp (-\mathrm{KTP}{2}_{\mathrm{RPS}}\·{[T-{\mathrm{TP}2}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\≥{\mathrm{TP}2}_{\mathrm{RPS}}\end{array}\right\}$

T represents the time (d);

H is the depth of water (m), input data;

I _ofor light radiation (umol/m ²/ s), input data;

T be water temperature (℃), input data;

RPS is submerged plant stem biomass (g C/m ²), unknown quantity;

F _pRPRfor directly transferring to product (the 0 < F of submerged plant root _pRPR< 1), 0.3;

P _rPSgrowth rate (d for submerged plant stem ^-1), unknown quantity;

PM _rPSmaximum growth rate (d for submerged plant stem ^-1), 0.8;

F (N) _rPS, f (P) _rPS, f (I) _rPS, f (T) _rPSbe respectively the nitrogen of submerged plant stem growth, phosphorus, illumination, temperature limiting function;

Kess is water body extinction coefficient (m ^-1), 0.475;

I _ssofor the optimum light intensity (umol/m of submerged plant growth ²/ s), 600;

HRPS is the average stem of submerged plant high (m), 0.8;

KHN _rPS/RPRbe respectively submerged plant from semi-saturation constant (the g N/m of water column/bed mud absorbed nitrogen ³), 0.19/0.95;

NH ₄/ NO ₃b is respectively concentration (the g N/m of bed mud ammonia nitrogen and nitrate nitrogen ³), 2.0/2.0;

KHP _rPS/RPRbe respectively submerged plant and from water column/bed mud, absorb semi-saturation constant (the g P/m of phosphorus ³), 0.19/0.95;

PO ₄b is respectively concentration (the g P/m of bed mud orthophosphate ³), 0.2;

KTP1/2 _rPSthe impact of while being respectively low temperature and high temperature, submerged plant stem being grown (℃ ^-2), 0.008/0.008;

TP1/2 _rPSbe respectively the lower limit of the raw Optimal Temperature of submerged plant stem and upper phase (℃), 22/33;

R _rPSrespiratory rate (d for submerged plant stem ^-1), 0.3;

L _rPSnon-breathing loss rate (d for submerged plant stem ^-1), 0.2;

JRP _rSfor submerged plant root is carried (g C/ (m to the positive carbon of submerged plant stem ²d)), 0.1;

RPR is submerged plant root biomass (g C/m ²), unknown quantity;

R _rPRrespiratory rate (d for submerged plant root ^-1), 0.1;

L _rPRnon-breathing loss rate (d for submerged plant root ^-1), 0.1;

RPE is epiphyte biomass (the g C/m on submerged plant ^-2), unknown quantity;

P _rPEfor epiphyte growth rate (d ^-1), 0.75;

R _pREfor epiphyte respiratory rate (d ^-1), 0.1;

L _rPEfor the non-breathing loss rate of epiphyte (d ^-1), 0.1;

RPD is biomass (the g C/m of submerged plant stem chip ²), unknown quantity;

F _rPSDfor the loss component (0-1) of stem chip, 0.2;

L _rPDfor chip decomposition rate, 0.1;

(4) to each model time step differential equation, finally obtain the biomass of submerged plant, complete the prediction of biomass of submerged plant.

A method of predicting the biomass of submerged plant by building growth simulation model, step is as follows:

(1) use analytical instrument of water quality to obtain the data of algae in lake, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, according to the relation between algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO in lake, obtain relevant dynamical mass conservation equation, i.e. water quality module:

Algae dynamical mass conservation equation:

$\frac{{\&PartialD;B}_g}{\&PartialD;t}=({\mathrm{WQP}}_g-{\mathrm{WQBM}}_g-{\mathrm{WQPR}}_g-\frac{{\mathrm{WS}}_g}{H})\&CenterDot;B_g$

$\frac{{\&PartialD;B}_c}{\&PartialD;t}=({\mathrm{WQP}}_c-{\mathrm{WQBM}}_c-{\mathrm{WQPR}}_c-\frac{{\mathrm{WS}}_c}{H})\&CenterDot;B_c$

Organic carbon dynamical mass conservation equation:

$\frac{\&PartialD;\mathrm{WQRPOC}}{\&PartialD;t}\underset{x=c,g}{\mathrm{\&Sigma;}}\mathrm{FCRP}\&CenterDot;{\mathrm{WQPR}}_x\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{RPOC}}\&CenterDot;\mathrm{WQRPOC}-\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQRPOC}}{H}$

$\frac{\&PartialD;\mathrm{WQLPOC}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}\mathrm{FCLP}\&CenterDot;{\mathrm{WQPR}}_x\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{LPOC}}\&CenterDot;\mathrm{WQLPOC}-\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQLPOC}}{H}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDOC}}{\&CenterDot;\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}[{\mathrm{FCD}}_x+(1-{\mathrm{FCD}}_X)\&CenterDot;\frac{{\mathrm{KHR}}_x}{{\mathrm{KHR}}_x+\mathrm{WQDO}}]{\mathrm{WQBM}}_x\&CenterDot;{\mathrm{WQB}}_x\\ +\underset{x=c,g}{\mathrm{\&Sigma;}}\mathrm{FCDP}\&CenterDot;{\mathrm{WQPR}}_x\&CenterDot;{\mathrm{WQB}}_x+K_{\mathrm{RPOC}}\&CenterDot;\mathrm{WQRPOC}\\ +{\mathrm{WQK}}_{\mathrm{LPOC}}\&CenterDot;\mathrm{WQLPOC}-{\mathrm{WQK}}_{\mathrm{HR}}\&CenterDot;\mathrm{WQDOC}-\mathrm{WQDenit}\&CenterDot;\mathrm{WQDOC}\end{array}$

Phosphorus dynamical mass conservation equation:

Nitrogen dynamics mass-conservation equation:

Dissolved oxygen DO dynamical mass conservation equation:

T represents the time (d);

H, for representing water level (m), inputs data;

B _g/cbe respectively biomass (the g C/m of green alga and blue-green algae ³), unknown quantity;

WQP _g/cbe respectively the throughput rate (d of green alga and blue-green algae ^-1), 1.2; 2.0;

WQBM _g/cbe respectively the basis metabolism speed (d of green alga and blue-green algae ^-1), 0.12; 0.05;

WQPR _g/cbe respectively the predation rate (d of green alga and blue-green algae ^-1);

WS _g/cbe respectively the subsidence rate (m/d) of green alga and blue-green algae, 0.04; 0.04;

WQRPOC is slightly solubility particulate organic carbon concentration (g C/m ³), unknown quantity;

WQLPOC is active particle organic carbon concentration (g C/m ³), unknown quantity;

WQDOC is dissolved organic carbon concentration (g C/m ³), unknown quantity;

FCRP is the slightly solubility particulate organic carbon part generating in the carbon of prey, 0.2;

FCLP is the active particle organic carbon part generating in the carbon of prey, 0.0;

FCDP is the dissolved organic carbon part generating in the carbon of prey, 0.8;

FCD is algae constant (0-1), 0;

WQK _rPOCfor slightly solubility particulate organic carbon hydrolysis rate (d ^-1), 0.005;

WQK _lPOCfor active particle organic carbon hydrolysis rate (d ^-1), 0;

WS _rp/lpbe respectively slightly solubility particle and active particle subsidence rate (m/d), 0.02; 0.02;

KHR is the excremental dissolved oxygen DO semi-saturation of algae dissolved organic carbon constant (g O ₂/ m ³), 0.5; 0.5;

WQDO is dissolved oxygen concentration (g O ₂/ m ³), unknown quantity;

WQK _hRdifferent oxygen respiratory rate (d for dissolved organic carbon ^-1), 0.3;

WQDenit is denitrification speed (d ^-1), 0.2;

WQRPOP is slightly solubility particulate organic phosphorus concentration (g P/m ³), unknown quantity;

WQLPOP is active particle organophosphorus concentration (g P/m ³), unknown quantity;

WQDOP is dissolubility organophosphorus concentration (g P/m ³), unknown quantity;

WQPO ₄for solubilised state phosphate concn (g P/m ³), unknown quantity;

FPR is that the metabolic phosphorus of algae is as the part of slightly solubility particulate organic phosphorus, 0.2;

FPL is that the metabolic phosphorus of algae is as the part of active particle organophosphorus, 0;

FPD is the dissolubility organophosphorus part generating in the phosphorus of algae metabolism, 0.6;

FPI is the Phos part generating in the phosphorus of algae metabolism, 0.2;

FPRP is the slightly solubility particulate organic phosphorus part generating in the phosphorus of prey, 0.2;

FPLP is the active particle organophosphorus part generating in the phosphorus of prey, 0;

FPDP is the dissolubility organophosphorus part generating in the phosphorus of prey, 0.6;

FPIP is the Phos part generating in the phosphorus of prey, 0.2;

WQAPC represents that the average phosphorus of algae is to the ratio of carbon (g P/g C), 0.02;

WQK _rPOPfor slightly solubility particulate organic phosphorus hydrolysis rate (d ^-1), 0.005;

WQK _lPOPfor active particle organophosphorus hydrolysis rate (d ^-1), 0;

WQK _dOPmineralization rate (d for dissolubility organophosphorus ^-1), 0;

BFPO ₄for bed mud-water column phosphate Flux (g N/ (m ²* d)), 0.2;

WQRPON is slightly solubility particulate organic nitrogen concentration (g N/m ³), unknown quantity;

WQLPON is active particle organic nitrogen concentration (g N/m ³), unknown quantity;

WQDON is soluble organic nitrogen concentration (g N/m ³), unknown quantity;

WQNH ₄for ammonia nitrogen concentration (g N/m ³), unknown quantity;

WQNO ₃for nitrate nitrogen concentration (g N/m ³), unknown quantity;

FNR is that the metabolic nitrogen of algae is as the part of slightly solubility particulate organic nitrogen, 0.2;

FNL is that the metabolic nitrogen of algae is as the part of active particle organic nitrogen, 0;

FND is the soluble organic nitrogen part generating in the nitrogen of algae metabolism, 0.7;

FNI is the inorganic nitrogen part generating in the phosphorus of algae metabolism, 0.1;

FNRP is the slightly solubility particulate organic nitrogen part generating in the nitrogen of prey, 0.2;

FNLP is the active particle organic nitrogen part generating in the nitrogen of prey, 0;

FNDP is the soluble organic nitrogen part generating in the nitrogen of prey, 0.7;

FNIP is the inorganic nitrogen part generating in the nitrogen of prey, 0.1;

WQANC represents that the average nitrogen of algae is to the ratio of carbon (g N/g C), 0.08;

WQK _rPONfor slightly solubility particulate organic nitrogen hydrolysis rate (d ^-1), 0.005;

WQK _lPONfor active particle organic nitrogen hydrolysis rate (d ^-1), 0;

WQK _dONmineralization rate (d for soluble organic nitrogen ^-1), 0.05;

ANDC is the quality of the nitrate nitrogen that reduces of the dissolved organic carbon of every oxidation unit mass, 0.933;

WQPN is that algae absorbs preference (0-1), 0.5 to ammonia;

WQNit is rate of nitrification (d ^-1), 0.01;

BFNH ₄for bed mud-water column ammonia nitrogen Flux (g N/ (m ²* d)), 2.0;

BFNO ₃for bed mud-water column nitrate nitrogen Flux (g N/ (m ²* d)), 2.0;

AONT is the nitrated required dissolved oxygen DO of the ammonium ion of unit mass, 4.33;

AOCR is the ratio of dissolved oxygen DO and carbon in respiration, 2.67;

WQK _rfor coefficient of aeration (d ^-1), 0.2;

WQDO _satfor dissolved oxygen DO saturation concentration (g O ₂/ m ³), 14;

SOD is bed mud oxygen demand (g O ₂/ m ³) ,-1.0;

(2), according to the stem of submerged plant, root be grown in the relation between the epiphyte of stem, obtain relevant dynamical mass conservation equation, i.e. submerged plant module:

$\frac{\&PartialD;\left(\mathrm{RPS}\right)}{\&PartialD;t}=[(1-F_{\mathrm{PRPR}})\&CenterDot;P_{\mathrm{RPS}}-R_{\mathrm{RPS}}-L_{\mathrm{RPS}}]\&CenterDot;\mathrm{RPS}+{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPR}\right)}{\&PartialD;t}=F_{\mathrm{PRPR}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-(R_{\mathrm{RPR}}+L_{\mathrm{RPR}})\&CenterDot;\mathrm{RPR}-{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPE}\right)}{\&PartialD;t}=(P_{\mathrm{RPE}}-R_{\mathrm{RPE}}-L_{\mathrm{RPE}})\&CenterDot;\mathrm{RPE}$

$\frac{\&PartialD;\left(\mathrm{RPD}\right)}{\&PartialD;t}=F_{\mathrm{RPSD}}\&CenterDot;L_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-L_{\mathrm{RPD}}\&CenterDot;\mathrm{RPD}$

P _RPS＝PM _RPS·min(f(N) _RPS，f(P) _RPS)·f(I) _RPS·f(T) _RPS

$f{\left(I\right)}_{\mathrm{RPS}}=\frac{2.718}{\mathrm{Kess}\&CenterDot;\mathrm{HRPS}}\left(\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;H)\right)-\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;(H-\mathrm{HRPS}))$

${f\left(N\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}{{\mathrm{KHN}}_{\mathrm{RPS}}+{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}$

${f\left(P\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}{{\mathrm{KHP}}_{\mathrm{RPS}}+{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}$

${f\left(T\right)}_{\mathrm{RPS}}=\left\{\begin{array}{cc}\exp (-\mathrm{KTP}{1}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}1}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&le;{\mathrm{TP}1}_{\mathrm{RPS}}\\ 1,& \mathrm{if}{\mathrm{TP}1}_{\mathrm{RPS}}\&le;T\&le;{\mathrm{TP}2}_{\mathrm{RPS}}\\ \exp (-\mathrm{KTP}{2}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}2}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&GreaterEqual;{\mathrm{TP}2}_{\mathrm{RPS}}\end{array}\right\}$

T represents the time (d);

H is the depth of water (m), input data;

I _ofor light radiation (umol/m ²/ s), input data;

T be water temperature (℃), input data;

RPS is submerged plant stem biomass (g C/m ²), unknown quantity;

F _pRPRfor directly transferring to product (the 0 < F of submerged plant root _pRPR< 1), 0.3;

P _rPSgrowth rate (d for submerged plant stem ^-1), unknown quantity;

PM _rPSmaximum growth rate (d for submerged plant stem ^-1), 0.8;

F (N) _rPS, f (P) _rPS, f (I) _rPS, f (T) _rPSbe respectively the nitrogen of submerged plant stem growth, phosphorus, illumination, temperature limiting function;

Kess is water body extinction coefficient (m ^-1), 0.475;

I _ssofor the optimum light intensity (umol/m of submerged plant growth ²/ s), 600;

HRPS is the average stem of submerged plant high (m), 0.8;

KHN _rPS/RPRbe respectively submerged plant from semi-saturation constant (the g N/m of water column/bed mud absorbed nitrogen ³), 0.19/0.95;

NH ₄/ NO ₃b is respectively concentration (the g N/m of bed mud ammonia nitrogen and nitrate nitrogen ³), 2.0/2.0;

KHP _rPS/RPRbe respectively submerged plant and from water column/bed mud, absorb semi-saturation constant (the g P/m of phosphorus ³), 0.19/0.95;

PO ₄b is respectively concentration (the g P/m of bed mud orthophosphate ³), 0.2;

KTP1/2 _rPSthe impact of while being respectively low temperature and high temperature, submerged plant stem being grown (℃ ^-2), 0.008/0.008;

TP1/2 _rPSbe respectively the lower limit of the raw Optimal Temperature of submerged plant stem and upper phase (℃), 22/33;

R _rPSrespiratory rate (d for submerged plant stem ^-1), 0.3;

L _rPSnon-breathing loss rate (d for submerged plant stem ^-1), 0.2;

JRP _rSfor submerged plant root is carried (g C/ (m to the positive carbon of submerged plant stem ²d)), 0.1;

RPR is submerged plant root biomass (g C/m ²), unknown quantity;

R _rPRrespiratory rate (d for submerged plant root ^-1), 0.1;

L _rPRnon-breathing loss rate (d for submerged plant root ^-1), 0.1;

RPE is epiphyte biomass (the g C/m on submerged plant ^-2), unknown quantity;

P _rPEfor epiphyte growth rate (d ^-1), 0.75;

R _pREfor epiphyte respiratory rate (d ^-1), 0.1;

L _rPEfor the non-breathing loss rate of epiphyte (d ^-1), 0.1;

RPD is biomass (the g C/m of submerged plant stem chip ²), unknown quantity;

F _rPSDfor the loss component (0-1) of stem chip, 0.2;

L _rPDfor chip decomposition rate, 0.1;

(3) water quality module and submerged plant module are coupled, relevant dynamical mass conservation equation adds the effect of submerged plant:

Between submerged plant module and water quality module, the coupled relation of organic carbon is given as:

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRPOC}}{\&PartialD;t}=\frac{{\mathrm{FCR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FCRL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FCR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FCRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FCRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQLPOC}}{\&PartialD;t}=\frac{{\mathrm{FCL}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FCLL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FCL}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FCLL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FCLL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRDOC}}{\&PartialD;t}=\frac{{\mathrm{FCD}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FCDL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FCD}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FCDL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FCDL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPD}\end{array}$

Between submerged plant module and water quality module, the coupled relation of dissolved oxygen DO is given as:

$\frac{\&PartialD;\mathrm{DO}}{\&PartialD;t}=\frac{P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSOC}\&CenterDot;\mathrm{RPS}+P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPEOC}\&CenterDot;\mathrm{RPE}}{H}$

Between submerged plant module and water quality module, the coupled relation of phosphorus is given as:

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRPOP}}{\&PartialD;t}=\frac{{\mathrm{FPR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPPL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQLPOP}}{\&PartialD;t}=\frac{{\mathrm{FPL}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPLL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPL}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPLL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPLL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDOP}}{\&PartialD;t}=\frac{{\mathrm{FPD}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPDL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPD}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPDL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPDL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{{\&PartialD;\mathrm{WQPO}}_4}{\&PartialD;t}=\frac{{\mathrm{FPI}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPIL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPI}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPIL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPIL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\\ -\frac{F_{\mathrm{RPSPW}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}}{H}-\frac{P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}}{H}\end{array}$

Between submerged plant module and water quality module, the coupled relation of nitrogen is given as:

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRPON}}{\&PartialD;t}=\frac{{\mathrm{FNR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNRL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FNR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FNRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQLPON}}{\&PartialD;t}=\frac{{\mathrm{FNL}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNRL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FNR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FNRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDON}}{\&PartialD;t}=\frac{{\mathrm{FND}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNDL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FND}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNDL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FNDL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{{\&PartialD;\mathrm{WQNH}}_4}{\&PartialD;t}=\frac{{\mathrm{FNI}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNIL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FNI}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNIL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\\ -\frac{{\mathrm{PN}}_{\mathrm{RPS}}\&CenterDot;F_{\mathrm{RPSNW}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}}{H}-\frac{{\mathrm{PN}}_{\mathrm{RPE}}\&CenterDot;P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}}{H}\end{array}$

$\frac{{\&PartialD;\mathrm{WQNO}}_3}{\&PartialD;t}=-\frac{(1-{\mathrm{PN}}_{\mathrm{RPS}})\&CenterDot;F_{\mathrm{RPSNW}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}}{H}-\frac{(1-{\mathrm{PN}}_{\mathrm{RPE}})\&CenterDot;P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}}{H}$

T represents the time (d);

H, for representing water level (m), inputs data;

WQRPOC is slightly solubility particulate organic carbon concentration (g C/m ³), unknown quantity;

WQLPOC is active particle organic carbon concentration (g C/m ³), unknown quantity;

WQDOC is dissolved organic carbon concentration (g C/m ³), unknown quantity;

RPS is submerged plant stem biomass (g C/m ²), unknown quantity;

F _pRPRfor directly transferring to product (the 0 < F of submerged plant root _pRPR< 1), 0.3;

P _rPSgrowth rate (d for submerged plant stem ^-1), 0.8;

R _rPSrespiratory rate (d for submerged plant stem ^-1), 0.3;

L _rPSnon-breathing loss rate (d for submerged plant stem ^-1), 0.2;

JRP _rSfor submerged plant root is carried (g C/ (m to the positive carbon of submerged plant stem ²d)), 0.1;

RPR is submerged plant root biomass (g C/m ²), unknown quantity;

R _rPRrespiratory rate (d for submerged plant root ^-1), 0.1;

L _rPRnon-breathing loss rate (d for submerged plant root ^-1);

RPE is epiphyte biomass (the g C/m on submerged plant ^-2), unknown quantity;

P _rPEfor epiphyte growth rate (d ^-1), 0.75;

R _pREfor epiphyte respiratory rate (d ^-1), 0.1;

L _rPEfor the non-breathing loss rate of epiphyte (d ^-1), 0.1;

RPD is biomass (the g C/m of submerged plant stem chip ²), unknown quantity;

F _rPSDfor the loss component (0-1) of stem chip, 0.2;

L _rPDfor chip decomposition rate, 0.1;

FCR is for breathing the slightly solubility particulate organic carbon part producing, 0.2;

FCL is for breathing the active particle organic carbon part producing, 0;

FCD is for breathing the dissolved organic carbon part producing, 0.8;

FCRL is the slightly solubility particulate organic carbon loss part that non-respiration causes, 0.2;

FCLL is the dissolubility particulate organic carbon loss part that non-respiration causes, 0;

FCDL is the dissolved organic carbon loss part that non-respiration causes, 0.8;

RPSOC is submerged plant stem carbon ratio, 0.2;

RPEOC is epiphyte carbon ratio, 0.2;

WQRPOP is slightly solubility particulate organic phosphorus concentration (g P/m ³), unknown quantity;

WQLPOP is active particle organophosphorus concentration (g P/m ³), unknown quantity;

WQDOP is dissolubility organophosphorus concentration (g P/m ³), unknown quantity;

WQPO ₄for solubilised state phosphate concn (g P/m ³).Unknown quantity;

FPR is for breathing the slightly solubility particulate organic phosphorus part producing, 0.2;

FPL is for breathing the active particle organophosphorus part producing, 0;

FPD is for breathing the dissolubility organophosphorus part producing, 0.6;

FPI is for breathing the dissolubility Phos part producing, 0.2;

FPRL is the slightly solubility particulate organic phosphorus loss part that non-respiration causes, 0.2;

FPLL is the dissolubility particulate organic phosphorus loss part that non-respiration causes, 0;

FPDL is the dissolubility organophosphorus loss part that non-respiration causes, 0.6;

FPIL is the dissolubility Phos loss part that non-respiration causes, 0.2;

RPSPC is submerged plant stem phosphorus carbon ratio, 0.011;

RPEPC is epiphyte phosphorus carbon ratio, 0.011;

F _rPSPWfor absorbing PO from water column ₄component, 0.4;

WQRPON is slightly solubility particulate organic nitrogen concentration (g N/m ³), unknown quantity;

WQLPON is active particle organic nitrogen concentration (g N/m ³), unknown quantity;

WQDON is soluble organic nitrogen concentration (g N/m ³), unknown quantity;

WQNH ₄for ammonia nitrogen concentration (g N/m ³), unknown quantity;

WQNO ₃for nitrate nitrogen concentration (g N/m ³), unknown quantity;

FNR is for breathing the slightly solubility particulate organic nitrogen part producing, 0.1;

FNL is for breathing the active particle organic nitrogen part producing, 0.2;

FND is for breathing the soluble organic nitrogen part producing, 0;

FNI is for breathing the ammonia components producing, 0.7;

FNRL is the slightly solubility particulate organic nitrogen loss part that non-respiration causes, 0.1;

FNLL is the dissolubility particulate organic nitrogen loss part that non-respiration causes, 0.2;

FNDL is the soluble organic nitrogen loss part that non-respiration causes, 0;

FNIL is the ammonia components that non-respiration causes, 0.7;

RPSNC is submerged plant stem carbon-nitrogen ratio, 0.18;

RPENC is epiphyte carbon-nitrogen ratio, 0.18;

F _rPSNWfor absorbing NH4 from water column ₄and NO ₃component, 0.4;

PN _rPSfor the Preference mark of submerged plant stem to ammonium ion, 0.2;

PN _rPEfor the Preference mark of epiphyte to ammonium ion, 0.2;

(4) according to growth simulation model, predict as follows again the biomass of submerged plant in shallow lake:

1) the meteorological hydrographic data of shallow lake is inputted to constructed growth simulation model, and set algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, submerged plant initial value and growth simulation model parameter value;

2) the dynamical mass conservation equation that growth simulation model relates to has following general formula:

$\frac{\&PartialD;C}{\&PartialD;t}=a\&CenterDot;C+b$

In formula, C is concentration, a, and b is constant;

This equation can calculate with implied format below:

$\frac{C^{n+1}-C^n}{\mathrm{\&Delta;t}}=a\&CenterDot;C^{n+1}+b$

In formula, n represents n time step;

Utilize said method to solve the growth simulation model differential equation, each model time step, all state variables are upgraded;

3) to each model time step differential equation, finally obtain the biomass of submerged plant, complete the prediction of biomass of submerged plant.

Beneficial effect of the present invention:

1. growth simulation model is by a large amount of detailed submerged plant physiological data of input and the environmental data of every day, every day or the seasonal growth trend that can more effectively predict aquatic macrophyte, provide more scientific and reasonable reference data and suggestion to eutrophic lake submerged plant recovery project.

2. in the history of life of submerged plant, sediment provides plant fixation matrix and required macronutrient, and the ups and downs of submerged plant are had to long-term and far-reaching influence, to the calculating of biomass of submerged plant, can to lake, process more targetedly.

Accompanying drawing explanation

Fig. 1---simulation system framework schematic diagram

Fig. 2---program flow chart of the present invention

Fig. 3---biomass of submerged plant analog result

Embodiment

Below in conjunction with embodiment, the invention will be further described.

The present invention is comprised of two parts: water quality module and submerged plant module.Water quality module in water body water-quality guideline (DO, TP, PO ₄ ^3--P, TN, NO ₃ ^--N, NH ₄ ⁺-N, Chla) carry out dynamic similation, for providing illumination, temperature and nutriment, submerged plant forces function.Submerged plant module is described submerged plant growth and decomposition.

A method of predicting the biomass of submerged plant by building growth simulation model, step is as follows:

(1) use analytical instrument of water quality to obtain the data of algae in lake, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, according to the relation between algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO in lake, obtain relevant dynamical mass conservation equation, i.e. water quality module;

(2), according to the stem of submerged plant, root be grown in the relation between the epiphyte of stem, obtain relevant dynamical mass conservation equation, i.e. submerged plant module;

(3) water quality module and submerged plant module are coupled, relevant dynamical mass conservation equation adds the effect of submerged plant;

(4) to each model time step differential equation, finally obtain the biomass of submerged plant, complete the prediction of biomass of submerged plant.

A method of predicting the biomass of submerged plant by building growth simulation model, step is as follows:

(1) use analytical instrument of water quality to obtain the data of algae in lake, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, according to the relation between algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO in lake, obtain relevant dynamical mass conservation equation, i.e. water quality module;

(2), according to the stem of submerged plant, root be grown in the relation between the epiphyte of stem, obtain relevant dynamical mass conservation equation, i.e. submerged plant module;

(3) water quality module and submerged plant module are coupled, relevant dynamical mass conservation equation adds the effect of submerged plant;

Described water quality module in water body water-quality guideline (DO, TP, PO ₄ ^3--P, TN, NO ₃ ^--N, NH ₄ ⁺-N, Chla) carry out dynamic similation, for providing illumination, temperature, nutriment and other, submerged plant forces function;

Described submerged plant module is described submerged plant growth and decomposition; Submerged plant module comprises 3 state variables: stem (biomass in water column), root (biomass in substrate) and epiphyte (growing in the plant of submerged plant leaf table); Stem consumes the nutriment in water body and consumes the nutriment in substrate by root; Epiphyte absorbs the nutriment in water body; Root and substrate exchange nutriment.The stem of submerged plant, root and the epiphytic dynamical mass conservation equation that is grown in stem are:

$\frac{\&PartialD;\left(\mathrm{RPS}\right)}{\&PartialD;t}=[(1-F_{\mathrm{PRPR}})\&CenterDot;P_{\mathrm{RPS}}-R_{\mathrm{RPS}}-L_{\mathrm{RPS}}]\&CenterDot;\mathrm{RPS}+{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPR}\right)}{\&PartialD;t}=F_{\mathrm{PRPR}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-(R_{\mathrm{RPR}}+L_{\mathrm{RPR}})\&CenterDot;\mathrm{RPR}-{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPE}\right)}{\&PartialD;t}=(P_{\mathrm{RPE}}-R_{\mathrm{RPE}}-L_{\mathrm{RPE}})\&CenterDot;\mathrm{RPE}$

$\frac{\&PartialD;\left(\mathrm{RPD}\right)}{\&PartialD;t}{=F}_{\mathrm{RPSD}}\&CenterDot;L_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-L_{\mathrm{RPD}}\&CenterDot;\mathrm{RPD}$

P _RPS＝PM _RPS·min(f(N) _RPS，f(P) _RPS)·f(I) _RPS·f(T) _RPS

${f\left(I\right)}_{\mathrm{RPS}}=\frac{2.718}{\mathrm{Kess}\&CenterDot;\mathrm{HRPS}}(\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;H))-\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;(H-\mathrm{HRPS}))$

${f\left(N\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}{{\mathrm{KHN}}_{\mathrm{RPS}}+{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}$

${f\left(P\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}{{\mathrm{KHP}}_{\mathrm{RPS}}+{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}$

${f\left(T\right)}_{\mathrm{RPS}}=\left\{\begin{array}{cc}\exp (-\mathrm{KTP}{1}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}1}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&le;{\mathrm{TP}1}_{\mathrm{RPS}}\\ 1,& \mathrm{if}{\mathrm{TP}1}_{\mathrm{RPS}}\&le;T\&le;{\mathrm{TP}2}_{\mathrm{RPS}}\\ \exp (-\mathrm{KTP}{2}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}2}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&GreaterEqual;{\mathrm{TP}2}_{\mathrm{RPS}}\end{array}\right\}$

T represents the time (d);

H is the depth of water (m), input data;

I _ofor light radiation (umol/m ²/ s), input data;

T be water temperature (℃), input data;

RPS is submerged plant stem biomass (g C/m ²), unknown quantity;

F _pRPRfor directly transferring to product (the 0 < F of submerged plant root _pRPR< 1), 0.3;

P _rPSgrowth rate (d for submerged plant stem ^-1), unknown quantity;

PM _rPSmaximum growth rate (d for submerged plant stem ^-1), 0.8;

F (N) _rPS, f (P) _rPS, f (I) _rPS, f (T) _rPSbe respectively the nitrogen of submerged plant stem growth, phosphorus, illumination, temperature limiting function;

Kess is water body extinction coefficient (m ^-1), 0.475;

I _ssofor the optimum light intensity (umol/m of submerged plant growth ²/ s), 600;

HRPS is the average stem of submerged plant high (m), 0.8;

KHN _rPS/RPRbe respectively submerged plant from semi-saturation constant (the g N/m of water column/bed mud absorbed nitrogen ³), 0.19/0.95;

NH ₄/ NO ₃b is respectively concentration (the g N/m of bed mud ammonia nitrogen and nitrate nitrogen ³), 2.0/2.0;

KHP _rPS/RPRbe respectively submerged plant and from water column/bed mud, absorb semi-saturation constant (the g P/m of phosphorus ³), 0.19/0.95;

PO ₄b is respectively concentration (the g P/m of bed mud orthophosphate ³), 0.2;

KTP1/2 _rPSthe impact of while being respectively low temperature and high temperature, submerged plant stem being grown (℃ ^-2), 0.008/0.008;

TP1/2 _rPSbe respectively the lower limit of the raw Optimal Temperature of submerged plant stem and upper phase (℃), 22/33;

R _rPSrespiratory rate (d for submerged plant stem ^-1), 0.3;

L _rPSnon-breathing loss rate (d for submerged plant stem ^-1), 0.2;

JRP _rSfor submerged plant root is carried (g C/ (m to the positive carbon of submerged plant stem ²d)), 0.1;

RPR is submerged plant root biomass (g C/m ²), unknown quantity;

R _rPRrespiratory rate (d for submerged plant root ^-1), 0.1;

L _rPRnon-breathing loss rate (d for submerged plant root ^-1), 0.1;

RPE is epiphyte biomass (the g C/m on submerged plant ^-2), unknown quantity;

P _rPEfor epiphyte growth rate (d ^-1), 0.75;

R _pREfor epiphyte respiratory rate (d ^-1), 0.1;

L _rPEfor the non-breathing loss rate of epiphyte (d ^-1), 0.1;

RPD is biomass (the g C/m of submerged plant stem chip ²), unknown quantity;

F _rPSDfor the loss component (0-1) of stem chip, 0.2;

L _rPDfor chip decomposition rate, 0.1;

(4) to each model time step differential equation, finally obtain the biomass of submerged plant, complete the prediction of biomass of submerged plant.

A method of predicting the biomass of submerged plant by building growth simulation model, step is as follows:

(1) use analytical instrument of water quality to obtain the data of algae in lake, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, according to the relation between algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO in lake, obtain relevant dynamical mass conservation equation, i.e. water quality module:

Algae dynamical mass conservation equation:

$\frac{{\&PartialD;B}_g}{\&PartialD;t}=({\mathrm{WQP}}_g-{\mathrm{WQBM}}_g-{\mathrm{WQPR}}_g-\frac{{\mathrm{WS}}_g}{H})\&CenterDot;B_g$

$\frac{{\&PartialD;B}_c}{\&PartialD;t}=({\mathrm{WQP}}_c-{\mathrm{WQBM}}_c-{\mathrm{WQPR}}_c-\frac{{\mathrm{WS}}_c}{H})\&CenterDot;B_c$

Organic carbon dynamical mass conservation equation:

$\frac{\&PartialD;\mathrm{WQRPOC}}{\&PartialD;t}\underset{x=c,g}{\mathrm{\&Sigma;}}\mathrm{FCRP}\&CenterDot;{\mathrm{WQPR}}_x\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{RPOC}}\&CenterDot;\mathrm{WQRPOC}-\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQRPOC}}{H}$

$\frac{\&PartialD;\mathrm{WQLPOC}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}\mathrm{FCLP}\&CenterDot;{\mathrm{WQPR}}_x\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{LPOC}}\&CenterDot;\mathrm{WQLPOC}-\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQLPOC}}{H}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDOC}}{\&CenterDot;\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}[{\mathrm{FCD}}_x+(1-{\mathrm{FCD}}_x)\&CenterDot;\frac{{\mathrm{KHR}}_X}{{\mathrm{KHR}}_x+\mathrm{WQDO}}]{\mathrm{WQBM}}_x\&CenterDot;{\mathrm{WQB}}_x\\ +\underset{x=c,g}{\mathrm{\&Sigma;}}\mathrm{FCDP}\&CenterDot;{\mathrm{WQPR}}_x\&CenterDot;{\mathrm{WQB}}_x+K_{\mathrm{RPOC}}\&CenterDot;\mathrm{WQRPOC}\\ +{\mathrm{WQK}}_{\mathrm{LPOC}}\&CenterDot;\mathrm{WQLPOC}-{\mathrm{WQK}}_{\mathrm{HR}}\&CenterDot;\mathrm{WQDOC}-\mathrm{WQDenit}\&CenterDot;\mathrm{WQDOC}\end{array}$

Phosphorus dynamical mass conservation equation:

$\frac{\&PartialD;\mathrm{WQRPOP}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FPR}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FPRP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQAPC}\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{RPOP}}\&CenterDot;\mathrm{WQRPOP}+\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQRPOP}}{H}$

$\frac{\&PartialD;\mathrm{WQLPOP}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FPL}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FPLP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQAPC}\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{LPOP}}\&CenterDot;\mathrm{WQLPOP}+\frac{{\mathrm{WS}}_{\mathrm{lp}}\&CenterDot;\mathrm{WQLPOP}}{H}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDOP}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FPD}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FPDP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQAPC}\&CenterDot;{\mathrm{WQB}}_x+{\mathrm{WQK}}_{\mathrm{RPOP}}\&CenterDot;\mathrm{WQRPOP}\\ +{\mathrm{WQK}}_{\mathrm{LPOP}}\&CenterDot;\mathrm{WQLPOP}-{\mathrm{WQK}}_{\mathrm{DOP}}\&CenterDot;\mathrm{WQDOP}\end{array}$

$\frac{\&PartialD;\mathrm{WQP}{O}_4}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FPI}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FPIP}\&CenterDot;{\mathrm{WQPR}}_x-{\mathrm{WQP}}_x)\&CenterDot;\mathrm{WQAPC}\&CenterDot;{\mathrm{WQB}}_x+{\mathrm{WQK}}_{\mathrm{DOP}}\&CenterDot;\mathrm{WQDOP}+\frac{{\mathrm{BFPO}}_4}{H}$

Nitrogen dynamics mass-conservation equation:

$\frac{\&PartialD;\mathrm{WQRPON}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FNR}}_x{\mathrm{WQBM}}_x+\mathrm{FNRP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQANC}\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{RPOP}}\&CenterDot;\mathrm{WQRPON}+\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQRPON}}{H}$

$\frac{\&PartialD;\mathrm{WQLPON}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FNL}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FNLP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQANC}\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{LPON}}\&CenterDot;\mathrm{WQLPON}+\frac{{\mathrm{WS}}_{\mathrm{lp}}\&CenterDot;\mathrm{WQLPON}}{H}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDON}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FND}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FNDP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQANC}\&CenterDot;{\mathrm{WQB}}_x+{\mathrm{WQK}}_{\mathrm{RPON}}\&CenterDot;\mathrm{WQRPON}\\ +{\mathrm{WQK}}_{\mathrm{LPON}}\&CenterDot;\mathrm{WQLPON}-{\mathrm{WQK}}_{\mathrm{DON}}\&CenterDot;\mathrm{WQDON}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQN}{H}_4}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FNI}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FNIP}\&CenterDot;{\mathrm{WQPR}}_x-{\mathrm{WQPN}}_x\&CenterDot;{\mathrm{WQP}}_x)\&CenterDot;{\mathrm{WQAPC}}_x+{\mathrm{WQB}}_X\\ +{\mathrm{WQK}}_{\mathrm{DON}}\&CenterDot;\mathrm{WQDON}-\mathrm{WQNit}-{\mathrm{WQNH}}_4\&CenterDot;\frac{{\mathrm{BFNH}}_4}{H}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQ}{\mathrm{NO}}_3}{\&PartialD;t}=-\underset{x=c,g}{\mathrm{\&Sigma;}}(1-{\mathrm{WQPN}}_x)\&CenterDot;{\mathrm{WQP}}_x\&CenterDot;{\mathrm{WQANC}}_x\&CenterDot;{\mathrm{WQB}}_x\\ +\mathrm{WQNit}\&CenterDot;{\mathrm{WQNH}}_4-\mathrm{ANDC}\&CenterDot;\mathrm{WQDenit}\&CenterDot;\mathrm{WQDOC}+\frac{{\mathrm{BFNO}}_3}{H}\end{array}$

Dissolved oxygen DO dynamical mass conservation equation:

$\begin{array}{c}\frac{\&PartialD;\mathrm{DO}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}((1.3-0.3\&CenterDot;{\mathrm{WQPN}}_x)\&CenterDot;{\mathrm{WQP}}_x-(1-{\mathrm{FCD}}_x)\&CenterDot;\frac{\mathrm{WQDO}}{{\mathrm{KHR}}_x+\mathrm{WQDO}}\&CenterDot;{\mathrm{WQBM}}_x)\&CenterDot;\mathrm{AOCR}\&CenterDot;{\mathrm{WQB}}_x\\ -\mathrm{AONT}\&CenterDot;\mathrm{WQNit}\&CenterDot;{\mathrm{WQNH}}_4-\mathrm{AOCR}\&CenterDot;\mathrm{WQKHR}\&CenterDot;\mathrm{WQDOC}+{\mathrm{WQK}}_r\&CenterDot;({\mathrm{WQO}}_{\mathrm{sat}}-\mathrm{WQDO})+\frac{\mathrm{SOD}}{H}\end{array}---\left(2\right)$

T represents the time (d);

H, for representing water level (m), inputs data;

B _g/cbe respectively biomass (the g C/m of green alga and blue-green algae ³), unknown quantity;

WQP _g/cbe respectively the throughput rate (d of green alga and blue-green algae ^-1), 1.2; 2.0;

WQBM _g/cbe respectively the basis metabolism speed (d of green alga and blue-green algae ^-1), 0.12; 0.05;

WQPR _g/cbe respectively the predation rate (d of green alga and blue-green algae ^-1);

WS _g/cbe respectively the subsidence rate (m/d) of green alga and blue-green algae, 0.04; 0.04;

WQRPOC is slightly solubility particulate organic carbon concentration (g C/m ³), unknown quantity;

WQLPOC is active particle organic carbon concentration (g C/m ³), unknown quantity;

WQDOC is dissolved organic carbon concentration (g C/m ³), unknown quantity;

FCRP is the slightly solubility particulate organic carbon part generating in the carbon of prey, 0.2;

FCLP is the active particle organic carbon part generating in the carbon of prey, 0.0;

FCDP is the dissolved organic carbon part generating in the carbon of prey, 0.8;

FCD is algae constant (0-1), 0;

WQK _rPOCfor slightly solubility particulate organic carbon hydrolysis rate (d ^-1), 0.005;

WQK _lPOCfor active particle organic carbon hydrolysis rate (d ^-1), 0;

WS _rp/lpbe respectively slightly solubility particle and active particle subsidence rate (m/d), 0.02; 0.02;

KHR is the excremental dissolved oxygen DO semi-saturation of algae dissolved organic carbon constant (g O ₂/ m ³), 0.5; 0.5;

WQDO is dissolved oxygen concentration (g O ₂/ m ³), unknown quantity;

WQK _hRdifferent oxygen respiratory rate (d for dissolved organic carbon ^-1), 0.3;

WQDenit is denitrification speed (d ^-1), 0.2;

WQRPOP is slightly solubility particulate organic phosphorus concentration (g P/m ³), unknown quantity;

WQLPOP is active particle organophosphorus concentration (g P/m ³), unknown quantity;

WQDOP is dissolubility organophosphorus concentration (g P/m ³), unknown quantity;

WQPO ₄for solubilised state phosphate concn (g P/m ³), unknown quantity;

FPR is that the metabolic phosphorus of algae is as the part of slightly solubility particulate organic phosphorus, 0.2;

FPL is that the metabolic phosphorus of algae is as the part of active particle organophosphorus, 0;

FPD is the dissolubility organophosphorus part generating in the phosphorus of algae metabolism, 0.6;

FPI is the Phos part generating in the phosphorus of algae metabolism, 0.2;

FPRP is the slightly solubility particulate organic phosphorus part generating in the phosphorus of prey, 0.2;

FPLP is the active particle organophosphorus part generating in the phosphorus of prey, 0;

FPDP is the dissolubility organophosphorus part generating in the phosphorus of prey, 0.6;

FPIP is the Phos part generating in the phosphorus of prey, 0.2;

WQAPC represents that the average phosphorus of algae is to the ratio of carbon (g P/g C), 0.02;

WQK _rPOPfor slightly solubility particulate organic phosphorus hydrolysis rate (d ^-1), 0.005;

WQK _lPOPfor active particle organophosphorus hydrolysis rate (d ^-1), 0;

WQK _dOPmineralization rate (d for dissolubility organophosphorus ^-1), 0;

BFPO ₄for bed mud-water column phosphate Flux (g N/ (m ²* d)), 0.2;

WQRPON is slightly solubility particulate organic nitrogen concentration (g N/m ³), unknown quantity;

WQLPON is active particle organic nitrogen concentration (g N/m ³), unknown quantity;

WQDON is soluble organic nitrogen concentration (g N/m ³), unknown quantity;

WQNH ₄for ammonia nitrogen concentration (g N/m ³), unknown quantity;

WQNO ₃for nitrate nitrogen concentration (g N/m ³), unknown quantity;

FNR is that the metabolic nitrogen of algae is as the part of slightly solubility particulate organic nitrogen, 0.2;

FNL is that the metabolic nitrogen of algae is as the part of active particle organic nitrogen, 0;

FND is the soluble organic nitrogen part generating in the nitrogen of algae metabolism, 0.7;

FNI is the inorganic nitrogen part generating in the phosphorus of algae metabolism, 0.1;

FNRP is the slightly solubility particulate organic nitrogen part generating in the nitrogen of prey, 0.2;

FNLP is the active particle organic nitrogen part generating in the nitrogen of prey, 0;

FNDP is the soluble organic nitrogen part generating in the nitrogen of prey, 0.7;

FNIP is the inorganic nitrogen part generating in the nitrogen of prey, 0.1;

WQANC represents that the average nitrogen of algae is to the ratio of carbon (g N/g C), 0.08;

WQK _rPONfor slightly solubility particle organic amino hydrolysis rate (d ^-1), 0.005;

WQK _lPONfor active particle organic nitrogen hydrolysis rate (d ^-1), 0;

WQK _dONmineralization rate (d for soluble organic nitrogen ^-1), 0.05;

ANDC is the quality of the nitrate nitrogen that reduces of the dissolved organic carbon of every oxidation unit mass, 0.933;

WQPN is that algae absorbs preference (0-1), 0.5 to ammonia;

WQNit is rate of nitrification (d ^-1), 0.01;

BFNH ₄for bed mud-water column ammonia nitrogen Flux (g N/ (m ²* d)), 2.0;

BFNO ₃for bed mud-water column nitrate nitrogen Flux (g N/ (m ²* d)), 2.0;

AONT is the nitrated required dissolved oxygen DO of the ammonium ion of unit mass, 4.33;

AOCR is the ratio of dissolved oxygen DO and carbon in respiration, 2.67;

WQK _rfor coefficient of aeration (d ^-1), 0.2;

WQDO _satfor dissolved oxygen DO saturation concentration (g O ₂/ m ³), 14;

SOD is bed mud oxygen demand (g O ₂/ m ³) ,-1.0;

(2), according to the stem of submerged plant, root be grown in the relation between the epiphyte of stem, obtain relevant dynamical mass conservation equation, i.e. submerged plant module:

$\frac{\&PartialD;\left(\mathrm{RPS}\right)}{\&PartialD;t}=[(1-F_{\mathrm{PRPR}})\&CenterDot;P_{\mathrm{RPS}}-R_{\mathrm{RPS}}-L_{\mathrm{RPS}}]\&CenterDot;\mathrm{RPS}+{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPR}\right)}{\&PartialD;t}=F_{\mathrm{PRPR}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-(R_{\mathrm{RPR}}+L_{\mathrm{RPR}})\&CenterDot;\mathrm{RPR}-{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPE}\right)}{\&PartialD;t}=(P_{\mathrm{RPE}}-R_{\mathrm{RPE}}-L_{\mathrm{RPE}})\&CenterDot;\mathrm{RPE}$

$\frac{\&PartialD;\left(\mathrm{RPD}\right)}{\&PartialD;t}=F_{\mathrm{RPSD}}\&CenterDot;L_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-L_{\mathrm{RPD}}\&CenterDot;\mathrm{RPD}$

P _RPS＝PM _RPS·min(f(N) _RPS，f(P) _RPS)·f(I) _RPS·f(T) _RPS

$f{\left(I\right)}_{\mathrm{RPS}}=\frac{2.718}{\mathrm{Kess}\&CenterDot;\mathrm{HRPS}}\left(\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;H)\right)-\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;(H-\mathrm{HRPS}))$

${f\left(N\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}{{\mathrm{KHN}}_{\mathrm{RPS}}+{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}$

${f\left(P\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}{{\mathrm{KHP}}_{\mathrm{RPS}}+{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}$

${f\left(T\right)}_{\mathrm{RPS}}=\left\{\begin{array}{cc}\exp (-\mathrm{KTP}{1}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}1}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&le;{\mathrm{TP}1}_{\mathrm{RPS}}\\ 1,& \mathrm{if}{\mathrm{TP}1}_{\mathrm{RPS}}\&le;T\&le;{\mathrm{TP}2}_{\mathrm{RPS}}\\ \exp (-\mathrm{KTP}{2}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}2}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&GreaterEqual;{\mathrm{TP}2}_{\mathrm{RPS}}\end{array}\right\}$

T represents the time (d);

H is the depth of water (m), input data;

I _ofor light radiation (umol/m ²/ s), input data;

T be water temperature (℃), input data;

RPS is submerged plant stem biomass (g C/m ²), unknown quantity;

F _pRPRfor directly transferring to product (the 0 < F of submerged plant root _pRPR< 1), 0.3;

P _rPSgrowth rate (d for submerged plant stem ^-1), unknown quantity;

PM _rPSmaximum growth rate (d for submerged plant stem ^-1), 0.8;

F (N) _rPS, f (P) _rPS, f (I) _rPS, f (T) _rPSbe respectively the nitrogen of submerged plant stem growth, phosphorus, illumination, temperature limiting function;

Kess is water body extinction coefficient (m ^-1), 0.475;

I _ssofor the optimum light intensity (umol/m of submerged plant growth ²/ s), 600;

HRPS is the average stem of submerged plant high (m), 0.8;

KHN _rPS/RPRbe respectively submerged plant from semi-saturation constant (the g N/m of water column/bed mud absorbed nitrogen ³), 0.19/0.95;

NH ₄/ NO ₃b is respectively concentration (the g N/m of bed mud ammonia nitrogen and nitrate nitrogen ³), 2.0/2.0;

KHP _rPS/RPRbe respectively submerged plant and from water column/bed mud, absorb semi-saturation constant (the g P/m of phosphorus ³), 0.19/0.95;

PO ₄b is respectively concentration (the g P/m of bed mud orthophosphate ³), 0.2;

KTP1/2 _rPSthe impact of while being respectively low temperature and high temperature, submerged plant stem being grown (℃ ^-2), 0.008/0.008;

TP1/2 _rPSbe respectively the lower limit of the raw Optimal Temperature of submerged plant stem and upper phase (℃), 22/33;

R _rPSrespiratory rate (d for submerged plant stem ^-1), 0.3;

L _rPSnon-breathing loss rate (d for submerged plant stem ^-1), 0.2;

JRP _rSfor submerged plant root is carried (g C/ (m to the positive carbon of submerged plant stem ²d)), 0.1;

RPR is submerged plant root biomass (g C/m ²), unknown quantity;

R _rPRrespiratory rate (d for submerged plant root ^-1), 0.1;

L _rPRnon-breathing loss rate (d for submerged plant root ^-1), 0.1;

RPE is epiphyte biomass (the g C/m on submerged plant ^-2), unknown quantity;

P _rPEfor epiphyte growth rate (d ^-1), 0.75;

R _pREfor epiphyte respiratory rate (d ^-1), 0.1;

L _rPEfor the non-breathing loss rate of epiphyte (d ^-1), 0.1;

RPD is biomass (the g C/m of submerged plant stem chip ²), unknown quantity;

F _rPSDfor the loss component (0-1) of stem chip, 0.2;

L _rPDfor chip decomposition rate, 0.1;

(3) water quality module and submerged plant module are coupled, relevant dynamical mass conservation equation adds the effect of submerged plant:

Between submerged plant module and water quality module, the coupled relation of organic carbon is given as:

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRPOC}}{\&PartialD;t}=\frac{{\mathrm{FCR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FCRL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FCR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FCRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FCRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQLPOC}}{\&PartialD;t}=\frac{{\mathrm{FCL}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FCLL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FCL}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FCLL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FCLL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRDOC}}{\&PartialD;t}=\frac{{\mathrm{FCD}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FCDL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FCD}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FCDL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FCDL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPD}\end{array}$

Between submerged plant module and water quality module, the coupled relation of dissolved oxygen DO is given as:

$\frac{\&PartialD;\mathrm{DO}}{\&PartialD;t}=\frac{P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSOC}\&CenterDot;\mathrm{RPS}+P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPEOC}\&CenterDot;\mathrm{RPE}}{H}$

Between submerged plant module and water quality module, the coupled relation of phosphorus is given as:

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRPOP}}{\&PartialD;t}=\frac{{\mathrm{FPR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPPL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQLPOP}}{\&PartialD;t}=\frac{{\mathrm{FPL}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPLL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPL}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPLL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPLL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDOP}}{\&PartialD;t}=\frac{{\mathrm{FPD}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPDL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPD}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPDL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPDL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{{\&PartialD;\mathrm{WQPO}}_4}{\&PartialD;t}=\frac{{\mathrm{FPI}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPIL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPI}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPIL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPIL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\\ -\frac{F_{\mathrm{RPSPW}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}}{H}-\frac{P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}}{H}\end{array}$

Between submerged plant module and water quality module, the coupled relation of nitrogen is given as:

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRPON}}{\&PartialD;t}=\frac{{\mathrm{FNR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNRL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FNR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FNRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQLPON}}{\&PartialD;t}=\frac{{\mathrm{FNL}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNRL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FNR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FNRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDON}}{\&PartialD;t}=\frac{{\mathrm{FND}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNDL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FND}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNDL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FNDL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{{\&PartialD;\mathrm{WQNH}}_4}{\&PartialD;t}=\frac{{\mathrm{FNI}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNIL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FNI}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNIL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\\ -\frac{{\mathrm{PN}}_{\mathrm{RPS}}\&CenterDot;F_{\mathrm{RPSNW}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}}{H}-\frac{{\mathrm{PN}}_{\mathrm{RPE}}\&CenterDot;P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}}{H}\end{array}$

$\frac{{\&PartialD;\mathrm{WQNO}}_3}{\&PartialD;t}=-\frac{(1-{\mathrm{PN}}_{\mathrm{RPS}})\&CenterDot;F_{\mathrm{RPSNW}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}}{H}-\frac{(1-{\mathrm{PN}}_{\mathrm{RPE}})\&CenterDot;P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}}{H}$

T represents the time (d);

H, for representing water level (m), inputs data;

WQRPOC is slightly solubility particulate organic carbon concentration (g C/m ³), unknown quantity;

WQLPOC is active particle organic carbon concentration (g C/m ³), unknown quantity;

WQDOC is dissolved organic carbon concentration (g C/m ³), unknown quantity;

RPS is submerged plant stem biomass (g C/m ²), unknown quantity;

F _pRPRfor directly transferring to product (the 0 < F of submerged plant root _pRPR< 1), 0.3;

P _rPSgrowth rate (d for submerged plant stem ^-1), 0.8;

R _rPSrespiratory rate (d for submerged plant stem ^-1), 0.3;

L _rPSnon-breathing loss rate (d for submerged plant stem ^-1), 0.2;

JRP _rSfor submerged plant root is carried (g C/ (m to the positive carbon of submerged plant stem ²d)), 0.1;

RPR is submerged plant root biomass (g C/m ²), unknown quantity;

R _rPRrespiratory rate (d for submerged plant root ^-1), 0.1;

L _rPRnon-breathing loss rate (d for submerged plant root ^-1);

RPE is epiphyte biomass (the g C/m on submerged plant ^-2), unknown quantity;

P _rPEfor epiphyte growth rate (d ^-1), 0.75;

R _pREfor epiphyte respiratory rate (d ^-1), 0.1;

L _rPEfor the non-breathing loss rate of epiphyte (d ^-1), 0.1;

RPD is biomass (the g C/m of submerged plant stem chip ²), unknown quantity;

F _rPSDfor the loss component (0-1) of stem chip, 0.2;

L _rPDfor chip decomposition rate, 0.1;

FCR is for breathing the slightly solubility particulate organic carbon part producing, 0.2;

FCL is for breathing the active particle organic carbon part producing, 0;

FCD is for breathing the dissolved organic carbon part producing, 0.8;

FCRL is the slightly solubility particulate organic carbon loss part that non-respiration causes, 0.2;

FCLL is the dissolubility particulate organic carbon loss part that non-respiration causes, 0;

FCDL is the dissolved organic carbon loss part that non-respiration causes, 0.8;

RPSOC is submerged plant stem carbon ratio, 0.2;

RPEOC is epiphyte carbon ratio, 0.2;

WQRPOP is slightly solubility particulate organic phosphorus concentration (g P/m ³), unknown quantity;

WQLPOP is active particle organophosphorus concentration (g P/m ³), unknown quantity;

WQDOP is dissolubility organophosphorus concentration (g P/m ³), unknown quantity;

WQPO ₄for solubilised state phosphate concn (g P/m ³).Unknown quantity;

FPR is for breathing the slightly solubility particulate organic phosphorus part producing, 0.2;

FPL is for breathing the active particle organophosphorus part producing, 0;

FPD is for breathing the dissolubility organophosphorus part producing, 0.6;

FPI is for breathing the dissolubility Phos part producing, 0.2;

FPRL is the slightly solubility particulate organic phosphorus loss part that non-respiration causes, 0.2;

FPLL is the dissolubility particulate organic phosphorus loss part that non-respiration causes, 0;

FPDL is the dissolubility organophosphorus loss part that non-respiration causes, 0.6;

FPIL is the dissolubility Phos loss part that non-respiration causes, 0.2;

RPSPC is submerged plant stem phosphorus carbon ratio, 0.011;

RPEPC is epiphyte phosphorus carbon ratio, 0.011;

F _rPSPWfor absorbing PO from water column ₄component, 0.4;

WQRPON is slightly solubility particulate organic nitrogen concentration (g N/m ³), unknown quantity;

WQLPON is active particle organic nitrogen concentration (g N/m ³), unknown quantity;

WQDON is soluble organic nitrogen concentration (g N/m ³), unknown quantity;

WQNH ₄for ammonia nitrogen concentration (g N/m ³), unknown quantity;

WQNO ₃for nitrate nitrogen concentration (g N/m ³), unknown quantity;

FNR is for breathing the slightly solubility particulate organic nitrogen part producing, 0,1;

FNL is for breathing the active particle organic nitrogen part producing, 0.2;

FND is for breathing the soluble organic nitrogen part producing, 0;

FNI is for breathing the ammonia components producing, 0.7;

FNRL is the slightly solubility particulate organic nitrogen loss part that non-respiration causes, 0.1;

FNLL is the dissolubility particulate organic nitrogen loss part that non-respiration causes, 0.2;

FNDL is the soluble organic nitrogen loss part that non-respiration causes, 0;

FNIL is the ammonia components that non-respiration causes, 0.7;

RPSNC is submerged plant stem carbon-nitrogen ratio, 0.18;

RPENC is epiphyte carbon-nitrogen ratio, 0.18;

F _rPSNWfor absorbing NH4 from water column ₄and NO ₃component, 0.4;

PN _rPSfor the Preference mark of submerged plant stem to ammonium ion, 0.2;

PN _rPEfor the Preference mark of epiphyte to ammonium ion, 0.2;

(4) according to growth simulation model, predict as follows again the biomass of submerged plant in shallow lake:

1) the meteorological hydrographic data of shallow lake is inputted to constructed growth simulation model, and set algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, submerged plant initial value and growth simulation model parameter value;

2) the dynamical mass conservation equation that growth simulation model relates to has following general formula:

$\frac{\&PartialD;C}{\&PartialD;t}=a\&CenterDot;C+b$

In formula, C is concentration, a, and b is constant;

This equation can calculate with implied format below:

$\frac{C^{n+1}-C^n}{\mathrm{\&Delta;t}}=a\&CenterDot;C^{n+1}+b$

In formula, n represents n time step;

Utilize said method to solve the growth simulation model differential equation, each model time step, all state variables are upgraded;

3) to each model time step differential equation, finally obtain the biomass of submerged plant, complete the prediction of biomass of submerged plant.

Simulative example: input Taihu Lake meteorology and hydrographic data in year Dec in Dec, 2009 to 2010, variable initial value is Taihu Lake measured value, such as weather data, comprise: solar radiation wind speed hydrographic data: the routine datas such as the water temperature depth of water, as follows: on Dec 31st, 1 2010 on November 25th, 2009, water level every one hour, water temperature, solar radiation data are as following table:

Time	Water level (m)	Water temperature (℃)	Solar radiation (umol/m 2/s)
				2009/11/2500∶00	2.8	8.0	0
2009/11/2501∶00	2.8	8.0	0
				2009/11/2502∶00	2.8	7.9	0
2009/11/2503∶00	2.8	7.9	0
				2009/11/2504∶00	2.8	7.9	0
2009/11/2505∶00	2.8	7.8	0
				2009/11/2506∶00	2.8	7.8	1.7
2009/11/2507∶00	2.8	7.8	200.9
				2009/11/2508∶00	2.8	7.9	517.2
2009/11/2509∶00	2.8	8.1	769.8
				2009/11/2510∶00	2.8	8.4	959.9
2009/11/2511∶00	2.8	8.7	1059.6
				2009/11/2512∶00	2.8	9.0	1059.6
2009/11/2513∶00	2.8	9.2	959.8
				2009/11/2514∶00	2.8	9.4	769.8
2009/11/2515∶00	2.8	9.5	507.3
				2009/11/2516∶00	2.8	9.5	197.1
2009/11/2517∶00	2.8	9.4	1.7
				2009/11/2518∶00	2.8	9.5	0
2009/11/2519∶00	2.8	9.5	0
				2009/11/2520∶00	2.8	9.4	0
2009/11/2521∶00	2.8	9.3	0
				2009/11/2522∶00	2.8	9.2	0
2009/11/2523∶00	2.8	9.0	0
				2009/11/2600∶00	2.8	8.9	0
……	……	……	……

Result of calculation is as following table: on Dec 31st, 1 2010 on November 25th, 2009, and the submerged plant stem every a hour, root and epiphytic biomass:

Time	Submerged plant Stem-leaf biomass (g C/m 2)	Submerged plant root biomass (g C/m 2)	Epiphyte biomass (g C/m 2)
				2009/11/2500∶00	100	20	5
2009/11/2501∶00	99.98	19.977	4.983
				2009/11/2502∶00	99.959	19.953	4.967
2009/11/2503∶00	99.939	19.93	4.95
				2009/11/2504∶00	99.919	19.906	4.933
2009/11/2505∶00	99.899	19.886	4.917
				2009/11/2506∶00	99.879	19.86	4.901

2009/11/2507∶00	99.868	19.84	4.904
				2009/11/2508∶00	99.856	19.821	4.911
2009/11/2509∶00	99.852	19.805	4.915
				2009/11/2510∶00	99.855	19.791	4.913
2009/11/2511∶00	99.863	19.78	4.907
				2009/11/2512∶00	99.875	19.771	4.9
2009/11/2513∶00	99.889	19.763	4.893
				2009/11/2514∶00	99.901	19.755	4.888
2009/11/2515∶00	99.91	19.745	4.89
				2009/11/2516∶00	99.91	19.731	4.903
2009/11/2517∶00	99.9	19.713	4.918
				2009/11/2518∶00	99.89	19.695	4.928
2009/11/2519∶00	99.867	19.672	4.911
				2009/11/2520∶00	99.845	19.648	4.894
2009/11/2521∶00	99.822	19.625	4.877
				2009/11/2522∶00	99.8	19.602	4.86
2009/11/2523∶00	99.778	19.579	4.843
				2009/11/2600∶00	99.756	19.555	4.826
……	……	……	……

Parameter value is pertinent literature and calibration gained, and Taihu Lake biomass of submerged plant is simulated, and analog result is shown in Fig. 3.By simulation, see and can see that biomass of submerged plant reaches peak value in August, and epiphyte biomass and biomass of submerged plant present negative correlation.

It should be noted, in all instructionss, the unknown quantity of parameter is all to obtain according to national standard.

The above, be only preferred embodiment of the present invention, is not the present invention to be done to the restriction of other form, and any those skilled in the art may utilize the technology contents of above-mentioned announcement to be changed or be modified as the equivalent embodiment of equivalent variations.But every technical solution of the present invention content that do not depart from, any simple modification, equivalent variations and the remodeling above embodiment done according to technical spirit of the present invention, still belong to the protection domain of technical solution of the present invention.

Claims (3)

1. by building growth simulation model, predict a method for the biomass of submerged plant, it is characterized in that step is as follows:

(1) use analytical instrument of water quality to obtain the data of algae in lake, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, according to the relation between algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO in lake, obtain relevant dynamical mass conservation equation, i.e. water quality module;

(2), according to the stem of submerged plant, root be grown in the relation between the epiphyte of stem, obtain relevant dynamical mass conservation equation, i.e. submerged plant module;

(3) water quality module and submerged plant module are coupled, relevant dynamical mass conservation equation adds the effect of submerged plant;

(4) to each model time step differential equation, finally obtain the biomass of submerged plant, complete the prediction of biomass of submerged plant.

2. by building growth simulation model, predict a method for the biomass of submerged plant, it is characterized in that step is as follows:

(1) use analytical instrument of water quality to obtain the data of algae in lake, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, according to the relation between algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO in lake, obtain relevant dynamical mass conservation equation, i.e. water quality module;

(2), according to the stem of submerged plant, root be grown in the relation between the epiphyte of stem, obtain relevant dynamical mass conservation equation, i.e. submerged plant module;

(3) water quality module and submerged plant module are coupled, relevant dynamical mass conservation equation adds the effect of submerged plant;

Described water quality module in water body water-quality guideline (DO, TP, PO ₄ ^3--P, TN, NO ₃ ^--N, NH ₄ ⁺-N, Chla) carry out dynamic similation, for providing illumination, temperature, nutriment and other, submerged plant forces function;

Described submerged plant module is described submerged plant growth and decomposition; Submerged plant module comprises 3 state variables: stem (biomass in water column), root (biomass in substrate) and epiphyte (growing in the plant of submerged plant leaf table); Stem consumes the nutriment in water body and consumes the nutriment in substrate by root; Epiphyte absorbs the nutriment in water body; Root and substrate exchange nutriment.The stem of submerged plant, root and the epiphytic dynamical mass conservation equation that is grown in stem are:

$\frac{\&PartialD;\left(\mathrm{RPS}\right)}{\&PartialD;t}=[(1-F_{\mathrm{PRPR}})\&CenterDot;P_{\mathrm{RPS}}-R_{\mathrm{RPS}}-L_{\mathrm{RPS}}]\&CenterDot;\mathrm{RPS}+{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPR}\right)}{\&PartialD;t}=F_{\mathrm{PRPR}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-(R_{\mathrm{RPR}}+L_{\mathrm{RPR}})\&CenterDot;\mathrm{RPR}-{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPE}\right)}{\&PartialD;t}=(P_{\mathrm{RPE}}-R_{\mathrm{RPE}}-L_{\mathrm{RPE}})\&CenterDot;\mathrm{RPE}$

$\frac{\&PartialD;\left(\mathrm{RPD}\right)}{\&PartialD;t}{=F}_{\mathrm{RPSD}}\&CenterDot;L_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-L_{\mathrm{RPD}}\&CenterDot;\mathrm{RPD}$

P _RPS＝PM _RPS·min(f(N) _RPS，f(P) _RPS)·f(I) _RPS·f(T) _RPS

${f\left(I\right)}_{\mathrm{RPS}}=\frac{2.718}{\mathrm{Kess}\&CenterDot;\mathrm{HRPS}}(\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;H))-\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;(H-\mathrm{HRPS}))$

${f\left(N\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}{{\mathrm{KHN}}_{\mathrm{RPS}}+{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}$

${f\left(P\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}{{\mathrm{KHP}}_{\mathrm{RPS}}+{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}$

${f\left(T\right)}_{\mathrm{RPS}}=\left\{\begin{array}{cc}\exp (-\mathrm{KTP}{1}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}1}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&le;{\mathrm{TP}1}_{\mathrm{RPS}}\\ 1,& \mathrm{if}{\mathrm{TP}1}_{\mathrm{RPS}}\&le;T\&le;{\mathrm{TP}2}_{\mathrm{RPS}}\\ \exp (-\mathrm{KTP}{2}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}2}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&GreaterEqual;{\mathrm{TP}2}_{\mathrm{RPS}}\end{array}\right\}$

T represents the time (d);

H is the depth of water (m), input data;

I _ofor light radiation (umol/m ²/ s), input data;

T be water temperature (℃), input data;

RPS is submerged plant stem biomass (g C/m ²), unknown quantity;

F _pRPRfor directly transferring to product (the 0 < F of submerged plant root _pRPR< 1), 0.3;

P _rPSgrowth rate (d for submerged plant stem ^-1), unknown quantity;

PM _rPSmaximum growth rate (d for submerged plant stem ^-1), 0.8;

F (N) _rPS, f (P) _rPS, f (I) _rPS, f (T) _rPSbe respectively the nitrogen of submerged plant stem growth, phosphorus, illumination, temperature limiting function;

Kess is water body extinction coefficient (m ^-1), 0.475;

I _ssofor the optimum light intensity (umol/m of submerged plant growth ²/ s), 600;

HRPS is the average stem of submerged plant high (m), 0.8;

KHN _rPS/RPRbe respectively submerged plant from semi-saturation constant (the g N/m of water column/bed mud absorbed nitrogen ³), 0.19/0.95;

NH ₄/ NO ₃b is respectively concentration (the g N/m of bed mud ammonia nitrogen and nitrate nitrogen ³), 2.0/2.0;

KHP _rPS/RPRbe respectively submerged plant and from water column/bed mud, absorb semi-saturation constant (the g P/m of phosphorus ³), 0.19/0.95;

PO ₄b is respectively concentration (the g P/m of bed mud orthophosphate ³), 0.2;

KTP1/2 _rPSthe impact of while being respectively low temperature and high temperature, submerged plant stem being grown (℃ ^-2), 0.008/0.008;

TP1/2 _rPSbe respectively the lower limit of the raw Optimal Temperature of submerged plant stem and upper phase (℃), 22/33;

R _rPSrespiratory rate (d for submerged plant stem ^-1), 0.3;

L _rPSnon-breathing loss rate (d for submerged plant stem ^-1), 0.2;

JRP _rSfor submerged plant root is carried (g C/ (m to the positive carbon of submerged plant stem ²d)), 0.1;

RPR is submerged plant root biomass (g C/m ²), unknown quantity;

R _rPRrespiratory rate (d for submerged plant root ^-1), 0.1;

L _rPRnon-breathing loss rate (d for submerged plant root ^-1), 0.1;

RPE is epiphyte biomass (the g C/m on submerged plant ^-2), unknown quantity;

P _rPEfor epiphyte growth rate (d ^-1), 0.75;

R _pREfor epiphyte respiratory rate (d ^-1), 0.1;

L _rPEfor the non-breathing loss rate of epiphyte (d ^-1), 0.1;

RPD is biomass (the g C/m of submerged plant stem chip ²), unknown quantity;

F _rPSDloss component (0 for stem chip ^-1), 0.2;

L _rPDfor chip decomposition rate, 0.1;

(4) to each model time step differential equation, finally obtain the biomass of submerged plant, complete the prediction of biomass of submerged plant.

3. a kind of method of predicting the biomass of submerged plant by building growth simulation model as claimed in claim 1, is characterized in that step is as follows:

(1) use analytical instrument of water quality to obtain the data of algae in lake, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, according to the relation between algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO in lake, obtain relevant dynamical mass conservation equation, i.e. water quality module:

Algae dynamical mass conservation equation:

$\frac{{\&PartialD;B}_g}{\&PartialD;t}=({\mathrm{WQP}}_g-{\mathrm{WQBM}}_g-{\mathrm{WQPR}}_g-\frac{{\mathrm{WS}}_g}{H})\&CenterDot;B_g$

$\frac{{\&PartialD;B}_c}{\&PartialD;t}=({\mathrm{WQP}}_c-{\mathrm{WQBM}}_c-{\mathrm{WQPR}}_c-\frac{{\mathrm{WS}}_c}{H})\&CenterDot;B_c$

Organic carbon dynamical mass conservation equation:

$\frac{\&PartialD;\mathrm{WQRPOC}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}\mathrm{FCRP}\&CenterDot;{\mathrm{WQPR}}_x\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{RPOC}}\&CenterDot;\mathrm{WQRPOC}-\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQRPOC}}{H}$

$\frac{\&PartialD;\mathrm{WQRPOC}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}\mathrm{FCLP}\&CenterDot;{\mathrm{WQPR}}_x\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{LPOC}}\&CenterDot;\mathrm{WQLPOC}-\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQLPOC}}{H}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDOC}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}[{\mathrm{FCD}}_x+(1-{\mathrm{FCD}}_x)\&CenterDot;\frac{{\mathrm{KHR}}_x}{{\mathrm{KHR}}_x+\mathrm{WQDO}}]{\mathrm{WQBM}}_x\&CenterDot;{\mathrm{WQB}}_x\\ +\underset{x=c,g}{\mathrm{\&Sigma;}}\mathrm{FCDP}\&CenterDot;{\mathrm{WQPR}}_x\&CenterDot;{\mathrm{WQB}}_x+K_{\mathrm{RPOC}}\&CenterDot;\mathrm{WQRPOC}\\ +{\mathrm{WQK}}_{\mathrm{LPOC}}\&CenterDot;\mathrm{WQLPOC}-{\mathrm{WQK}}_{\mathrm{HR}}\&CenterDot;\mathrm{WQDOC}-\mathrm{WQDenit}\&CenterDot;\mathrm{WQDOC}\end{array}$

Phosphorus dynamical mass conservation equation:

$\frac{\&PartialD;\mathrm{WQRPOP}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FPR}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FPRP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQAPC}\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{RPOP}}\&CenterDot;\mathrm{WQRPOP}+\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQRPOP}}{H}$

$\frac{\&PartialD;\mathrm{WQRPOP}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FPL}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FPLP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQAPC}\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{LPOP}}\&CenterDot;\mathrm{WQLPOP}+\frac{{\mathrm{WS}}_{\mathrm{lp}}\&CenterDot;\mathrm{WQRPOP}}{H}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDOP}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FPD}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FPDP}\&CenterDot;{\mathrm{WQRP}}_x)\&CenterDot;\mathrm{WQAPC}\&CenterDot;{\mathrm{WQB}}_x+{\mathrm{WQK}}_{\mathrm{RPOP}}\&CenterDot;\mathrm{WQRPOP}\\ +{\mathrm{WQK}}_{\mathrm{LPOP}}\&CenterDot;\mathrm{WQLPOP}-{\mathrm{WQK}}_{\mathrm{DOP}}\&CenterDot;\mathrm{WQDOP}\end{array}$

$\frac{{\&PartialD;\mathrm{WQPO}}_4}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FPI}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FPIP}\&CenterDot;{\mathrm{WQPR}}_x-{\mathrm{WQP}}_x)\&CenterDot;\mathrm{WQAPC}\&CenterDot;{\mathrm{WQB}}_x+{\mathrm{WQK}}_{\mathrm{DOP}}\&CenterDot;\mathrm{WQDOP}+\frac{{\mathrm{BFPO}}_4}{H}$

Nitrogen dynamics mass-conservation equation:

$\frac{\&PartialD;\mathrm{WQRPON}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FNR}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FNRP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQANC}\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{RPOP}\&CenterDot;}\mathrm{WQRPON}+\frac{{\mathrm{WS}}_{\mathrm{rp}}\&CenterDot;\mathrm{WQRPON}}{H}$

$\frac{\&PartialD;\mathrm{WQLPON}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FNL}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FNLP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQANC}\&CenterDot;{\mathrm{WQB}}_x-{\mathrm{WQK}}_{\mathrm{LPOP}\&CenterDot;}\mathrm{WQLPON}+\frac{{\mathrm{WS}}_{\mathrm{lp}}\&CenterDot;\mathrm{WQLPON}}{H}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDOP}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FND}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FNDP}\&CenterDot;{\mathrm{WQPR}}_x)\&CenterDot;\mathrm{WQANC}\&CenterDot;{\mathrm{WQB}}_x+{\mathrm{WQK}}_{\mathrm{RPON}}\&CenterDot;\mathrm{WQRPON}\\ +{\mathrm{WQK}}_{\mathrm{LPON}}\&CenterDot;\mathrm{WQLPON}-{\mathrm{WQK}}_{\mathrm{DON}}\&CenterDot;\mathrm{WQDON}\end{array}$

$\begin{array}{c}\frac{{\&PartialD;\mathrm{WQNH}}_4}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}({\mathrm{FNI}}_x\&CenterDot;{\mathrm{WQBM}}_x+\mathrm{FNIP}\&CenterDot;{\mathrm{WQPR}}_x-{\mathrm{WQPN}}_x\&CenterDot;{\mathrm{WQP}}_x)\&CenterDot;{\mathrm{WQAPC}}_x\&CenterDot;{\mathrm{WQB}}_x\\ +{\mathrm{WQK}}_{\mathrm{DON}}\&CenterDot;\mathrm{WQDON}-\mathrm{WQNit}\&CenterDot;{\mathrm{WQNH}}_4+\frac{{\mathrm{BFNH}}_4}{H}\end{array}$

$\begin{array}{c}\frac{{\&PartialD;\mathrm{WQNO}}_3}{\&PartialD;t}=-\underset{x=c,g}{\mathrm{\&Sigma;}}(1-{\mathrm{WQPN}}_x)\&CenterDot;{\mathrm{WQP}}_x\&CenterDot;{\mathrm{WQANC}}_x\&CenterDot;\mathrm{WQBx}\\ +\mathrm{WQNit}\&CenterDot;{\mathrm{WQN}H}_4-\mathrm{ANDC}\&CenterDot;\mathrm{WQDenit}\&CenterDot;\mathrm{WQDOC}+\frac{{\mathrm{BFNO}}_3}{H}\end{array}$

Dissolved oxygen DO dynamical mass conservation equation:

$\begin{array}{c}\frac{\&PartialD;\mathrm{DO}}{\&PartialD;t}=\underset{x=c,g}{\mathrm{\&Sigma;}}((1.3-0.3\&CenterDot;{\mathrm{WQPN}}_x)\&CenterDot;{\mathrm{WQP}}_x-(1-{\mathrm{FCD}}_x)\&CenterDot;\frac{\mathrm{WQDO}}{{\mathrm{KHR}}_x+\mathrm{WQDO}}\&CenterDot;{\mathrm{WQBM}}_x)\&CenterDot;\mathrm{AOCR}\&CenterDot;{\mathrm{WQB}}_x\\ -\mathrm{AQNT}\&CenterDot;\mathrm{WQNit}\&CenterDot;{\mathrm{WQNH}}_4-\mathrm{AOCR}\&CenterDot;\mathrm{WQKHR}\&CenterDot;\mathrm{WQDOC}+{\mathrm{WQK}}_r\&CenterDot;({\mathrm{WQO}}_{\mathrm{sat}}-\mathrm{WQDO})+\frac{\mathrm{SOD}}{H}\end{array}---\left(2\right)$

T represents the time (d);

H, for representing water level (m), inputs data;

B _g/cbe respectively biomass (the g C/m of green alga and blue-green algae ³), unknown quantity;

WQP _g/cbe respectively the throughput rate (d of green alga and blue-green algae ^-1), 1.2; 2.0;

WQBM _g/cbe respectively the basis metabolism speed (d of green alga and blue-green algae ^-1), 0.12; 0.05;

WQPR _g/cbe respectively the predation rate (d of green alga and blue-green algae ^-1);

WS _g/cbe respectively the subsidence rate (m/d) of green alga and blue-green algae, 0.04; 0.04;

WQRPOC is slightly solubility particulate organic carbon concentration (g C/m ³), unknown quantity;

WQLPOC is active particle organic carbon concentration (g C/m ³), unknown quantity;

WQDOC is dissolved organic carbon concentration (g C/m ³), unknown quantity;

FCRP is the slightly solubility particulate organic carbon part generating in the carbon of prey, 0.2;

FCLP is the active particle organic carbon part generating in the carbon of prey, 0.0;

FCDP is the dissolved organic carbon part generating in the carbon of prey, 0.8;

FCD is algae constant (0-1), 0;

WQK _rPOCfor slightly solubility particulate organic carbon hydrolysis rate (d ^-1), 0.005;

WQK _lPOCfor active particle organic carbon hydrolysis rate (d ^-1), 0;

WS _rp/lpbe respectively slightly solubility particle and active particle subsidence rate (m/d), 0.02; 0.02;

KHR is the excremental dissolved oxygen DO semi-saturation of algae dissolved organic carbon constant (g O ₂/ m ³), 0.5; 0.5;

WQDO is dissolved oxygen concentration (g O ₂/ m ³), unknown quantity;

WQK _hRdifferent oxygen respiratory rate (d for dissolved organic carbon ^-1), 0.3;

WQDenit is denitrification speed (d ^-1), 0.2;

WQRPOP is slightly solubility particulate organic phosphorus concentration (g P/m ³), unknown quantity;

WQLPOP is active particle organophosphorus concentration (g P/m ³), unknown quantity;

WQDOP is dissolubility organophosphorus concentration (g P/m ³), unknown quantity;

WQPO ₄for solubilised state phosphate concn (g P/m ³), unknown quantity;

FPR is that the metabolic phosphorus of algae is as the part of slightly solubility particulate organic phosphorus, 0.2;

FPL is that the metabolic phosphorus of algae is as the part of active particle organophosphorus, 0;

FPD is the dissolubility organophosphorus part generating in the phosphorus of algae metabolism, 0.6;

FPI is the Phos part generating in the phosphorus of algae metabolism, 0.2;

FPRP is the slightly solubility particulate organic phosphorus part generating in the phosphorus of prey, 0.2;

FPLP is the active particle organophosphorus part generating in the phosphorus of prey, 0;

FPDP is the dissolubility organophosphorus part generating in the phosphorus of prey, 0.6;

FPIP is the Phos part generating in the phosphorus of prey, 0.2;

WQAPC represents that the average phosphorus of algae is to the ratio of carbon (g P/g C), 0.02;

WQK _rPOPfor slightly solubility particulate organic phosphorus hydrolysis rate (d ^-1), 0.005;

WQK _lPOPfor active particle organophosphorus hydrolysis rate (d ^-1), 0;

WQK _dOPmineralization rate (d for dissolubility organophosphorus ^-1), 0;

BFPO ₄for bed mud-water column phosphate Flux (g N/ (m ²* d)), 0.2;

WQRPON is slightly solubility particulate organic nitrogen concentration (g N/m ³), unknown quantity;

WQLPON is active particle organic nitrogen concentration (g N/m ³), unknown quantity;

WQDON is soluble organic nitrogen concentration (g N/m ³), unknown quantity;

WQNH ₄for ammonia nitrogen concentration (g N/m ³), unknown quantity;

WQNO ₃for nitrate nitrogen concentration (g N/m ³), unknown quantity;

FNR is that the metabolic nitrogen of algae is as the part of slightly solubility particulate organic nitrogen, 0.2;

FNL is that the metabolic nitrogen of algae is as the part of active particle organic nitrogen, 0;

FND is the soluble organic nitrogen part generating in the nitrogen of algae metabolism, 0.7;

FNI is the inorganic nitrogen part generating in the phosphorus of algae metabolism, 0.1;

FNRP is the slightly solubility particulate organic nitrogen part generating in the nitrogen of prey, 0.2;

FNLP is the active particle organic nitrogen part generating in the nitrogen of prey, 0;

FNDP is the soluble organic nitrogen part generating in the nitrogen of prey, 0.7;

FNIP is the inorganic nitrogen part generating in the nitrogen of prey, 0.1;

WQANC represents that the average nitrogen of algae is to the ratio of carbon (g N/g C), 0.08;

WQK _rPONfor slightly solubility particulate organic nitrogen hydrolysis rate (d ^-1), 0.005;

WQK _lPONfor active particle organic nitrogen hydrolysis rate (d ^-1), 0;

WQK _dONmineralization rate (d for soluble organic nitrogen ^-1), 0.05;

ANDC is the quality of the nitrate nitrogen that reduces of the dissolved organic carbon of every oxidation unit mass, 0.933;

WQPN is that algae absorbs preference (0-1), 0.5 to ammonia;

WQNit is rate of nitrification (d ^-1), 0.01;

BFNH ₄for bed mud-water column ammonia nitrogen Flux (g N/ (m ²* d)), 2.0;

BFNO ₃for bed mud-water column nitrate nitrogen Flux (g N/ (m ²* d)), 2.0;

AONT is the nitrated required dissolved oxygen DO of the ammonium ion of unit mass, 4.33;

AOCR is the ratio of dissolved oxygen DO and carbon in respiration, 2.67;

WQK _rfor coefficient of aeration (d ^-1), 0.2;

WQDO _satfor dissolved oxygen DO saturation concentration (g O ₂/ m ³), 14;

SOD is bed mud oxygen demand (g O ₂/ m ³) ,-1.0;

(2), according to the stem of submerged plant, root be grown in the relation between the epiphyte of stem, obtain relevant dynamical mass conservation equation, i.e. submerged plant module:

$\frac{\&PartialD;\left(\mathrm{RPS}\right)}{\&PartialD;t}=[(1-F_{\mathrm{PRPR}})\&CenterDot;P_{\mathrm{RPS}}-R_{\mathrm{RPS}}-L_{\mathrm{RPS}}]\&CenterDot;\mathrm{RPS}+{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPR}\right)}{\&PartialD;t}=F_{\mathrm{PRPR}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-(R_{\mathrm{RPR}}+L_{\mathrm{RPR}})\&CenterDot;\mathrm{RPR}-{\mathrm{JRP}}_{\mathrm{RS}}$

$\frac{\&PartialD;\left(\mathrm{RPE}\right)}{\&PartialD;t}=(P_{\mathrm{RPE}}-R_{\mathrm{RPE}}-L_{\mathrm{RPE}})\&CenterDot;\mathrm{RPE}$

$\frac{\&PartialD;\left(\mathrm{RPD}\right)}{\&PartialD;t}{=F}_{\mathrm{RPSD}}\&CenterDot;L_{\mathrm{RPS}}\&CenterDot;\mathrm{RPS}-L_{\mathrm{RPD}}\&CenterDot;\mathrm{RPD}$

P _RPS＝PM _RPS·min(f(N) _RPS，f(P) _RPS)·f(I) _RPS·f(T) _RPS

${f\left(I\right)}_{\mathrm{RPS}}=\frac{2.718}{\mathrm{Kess}\&CenterDot;\mathrm{HRPS}}(\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;H))-\exp (-\frac{I_o}{I_{\mathrm{sso}}}\&CenterDot;\exp (-\mathrm{Kess}\&CenterDot;(H-\mathrm{HRPS}))$

${f\left(N\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}{{\mathrm{KHN}}_{\mathrm{RPS}}+{\mathrm{WQNH}}_4+{\mathrm{WQNO}}_3+\frac{{\mathrm{KHN}}_{\mathrm{RPS}}}{{\mathrm{KHN}}_{\mathrm{RPR}}}\&CenterDot;({\mathrm{NH}}_{4}B+{\mathrm{NO}}_{3}B)}$

${f\left(P\right)}_{\mathrm{RPS}}=\frac{{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}{{\mathrm{KHP}}_{\mathrm{RPS}}+{\mathrm{WQPO}}_4+\frac{{\mathrm{KHP}}_{\mathrm{RPS}}}{{\mathrm{KHP}}_{\mathrm{RPR}}}\&CenterDot;{\mathrm{PO}}_{4}B}$

${f\left(T\right)}_{\mathrm{RPS}}=\left\{\begin{array}{cc}\exp (-\mathrm{KTP}{1}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}1}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&le;{\mathrm{TP}1}_{\mathrm{RPS}}\\ 1,& \mathrm{if}{\mathrm{TP}1}_{\mathrm{RPS}}\&le;T\&le;{\mathrm{TP}2}_{\mathrm{RPS}}\\ \exp (-\mathrm{KTP}{2}_{\mathrm{RPS}}\&CenterDot;{[T-{\mathrm{TP}2}_{\mathrm{RPS}}]}^2),& \mathrm{if\; T}\&GreaterEqual;{\mathrm{TP}2}_{\mathrm{RPS}}\end{array}\right\}$

T represents the time (d);

H is the depth of water (m), input data;

I _ofor light radiation (umol/m ²/ s), input data;

T be water temperature (℃), input data;

RPS is submerged plant stem biomass (g C/m ²), unknown quantity;

F _pRPRfor directly transferring to product (the 0 < F of submerged plant root _pRPR< 1), 0.3;

P _rPSgrowth rate (d for submerged plant stem ^-1), unknown quantity;

PM _rPSmaximum growth rate (d for submerged plant stem ^-1), 0.8;

F (N) _rPS, f (P) _rPS, f (I) _rPS, f (T) _rPSbe respectively the nitrogen of submerged plant stem growth, phosphorus, illumination, temperature limiting function;

Kess is water body extinction coefficient (m ^-1), 0.475;

I _ssofor the optimum light intensity (umol/m of submerged plant growth ²/ s), 600;

HRPS is the average stem of submerged plant high (m), 0.8;

KHN _rPS/RPRbe respectively submerged plant from semi-saturation constant (the g N/m of water column/bed mud absorbed nitrogen ³), 0.19/0.95;

NH ₄/ NO ₃b is respectively concentration (the g N/m of bed mud ammonia nitrogen and nitrate nitrogen ³), 2.0/2.0;

KHP _rPS/RPRbe respectively submerged plant and from water column/bed mud, absorb semi-saturation constant (the g P/m of phosphorus ³), 0.19/0.95;

PO ₄b is respectively concentration (the g P/m of bed mud orthophosphate ³), 0.2;

KTP1/2 _rPSthe impact of while being respectively low temperature and high temperature, submerged plant stem being grown (℃ ^-2), 0.008/0.008;

TP1/2 _rPSbe respectively the lower limit of the raw Optimal Temperature of submerged plant stem and upper phase (℃), 22/33;

R _rPSrespiratory rate (d for submerged plant stem ^-1), 0.3;

L _rPSnon-breathing loss rate (d for submerged plant stem ^-1), 0.2;

JRP _rSfor submerged plant root is carried (g C/ (m to the positive carbon of submerged plant stem ²d)), 0.1;

RPR is submerged plant root biomass (g C/m ²), unknown quantity;

R _rPRrespiratory rate (d for submerged plant root ^-1), 0.1;

L _rPRnon-breathing loss rate (d for submerged plant root ^-1), 0.1;

RPE is epiphyte biomass (the g C/m on submerged plant ^-2), unknown quantity;

P _rPEfor epiphyte growth rate (d ^-1), 0.75;

R _pREfor epiphyte respiratory rate (d ^-1), 0.1;

L _rPEfor the non-breathing loss rate of epiphyte (d ^-1), 0.1;

RPD is biomass (the g C/m of submerged plant stem chip ²), unknown quantity;

F _rPSDfor the loss component (0-1) of stem chip, 0.2;

L _rPDfor chip decomposition rate, 0.1;

(3) water quality module and submerged plant module are coupled, relevant dynamical mass conservation equation adds the effect of submerged plant:

Between submerged plant module and water quality module, the coupled relation of organic carbon is given as:

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRPOC}}{\&PartialD;t}=\frac{{\mathrm{FCR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FCRL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FCR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FCRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FCRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQLPOC}}{\&PartialD;t}=\frac{{\mathrm{FCL}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FCLL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FCL}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FCLL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FCLL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRDOC}}{\&PartialD;t}=\frac{{\mathrm{FCD}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FCDL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FCD}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FCDL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FCDL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPD}\end{array}$

Between submerged plant module and water quality module, the coupled relation of dissolved oxygen DO is given as:

$\frac{\&PartialD;\mathrm{DO}}{\&PartialD;t}=\frac{P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSOC}\&CenterDot;\mathrm{RPS}+P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPEOC}\&CenterDot;\mathrm{RPE}}{H}$

Between submerged plant module and water quality module, the coupled relation of phosphorus is given as:

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRPOP}}{\&PartialD;t}=\frac{{\mathrm{FPR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPPL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQLPOP}}{\&PartialD;t}=\frac{{\mathrm{FPL}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPLL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPL}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPLL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPLL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDOP}}{\&PartialD;t}=\frac{{\mathrm{FPR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPDL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPD}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPDL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPDL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{{\&PartialD;\mathrm{WQPO}}_4}{\&PartialD;t}=\frac{{\mathrm{FPI}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FPIL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FPI}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FPIL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPIL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPD}\\ -\frac{F_{\mathrm{RPSPW}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSPC}\&CenterDot;\mathrm{RPS}}{H}-\frac{P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPEPC}\&CenterDot;\mathrm{RPE}}{H}\end{array}$

Between submerged plant module and water quality module, the coupled relation of nitrogen is given as:

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQRPON}}{\&PartialD;t}=\frac{{\mathrm{FNR}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNRL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FNR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FNRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQLPON}}{\&PartialD;t}=\frac{{\mathrm{FNL}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNRL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FNR}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNRL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FNRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{\&PartialD;\mathrm{WQDON}}{\&PartialD;t}=\frac{{\mathrm{FND}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNDL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FND}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNDL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FNDL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\end{array}$

$\begin{array}{c}\frac{{\&PartialD;\mathrm{WQNH}}_4}{\&PartialD;t}=\frac{{\mathrm{FNI}}_{\mathrm{RPS}}\&CenterDot;R_{\mathrm{RPS}}+(1-F_{\mathrm{RPSD}})\&CenterDot;{\mathrm{FNIL}}_{\mathrm{RPS}}\&CenterDot;L_{\mathrm{RPS}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}\\ +\frac{{\mathrm{FNI}}_{\mathrm{RPE}}\&CenterDot;R_{\mathrm{RPE}}+{\mathrm{FNIL}}_{\mathrm{RPE}}\&CenterDot;L_{\mathrm{RPE}}}{H}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}+\frac{{\mathrm{FPRL}}_{\mathrm{RPD}}\&CenterDot;L_{\mathrm{RPD}}}{H}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPD}\\ -\frac{{\mathrm{PN}}_{\mathrm{RPS}}\&CenterDot;F_{\mathrm{RPSNW}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}}{H}-\frac{{\mathrm{PN}}_{\mathrm{RPE}}\&CenterDot;P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}}{H}\end{array}$

$\frac{{\&PartialD;\mathrm{WQNO}}_3}{\&PartialD;t}=-\frac{(1-{\mathrm{PN}}_{\mathrm{RPS}})\&CenterDot;F_{\mathrm{RPSNW}}\&CenterDot;P_{\mathrm{RPS}}\&CenterDot;\mathrm{RPSNC}\&CenterDot;\mathrm{RPS}}{H}-\frac{(1-{\mathrm{PN}}_{\mathrm{RPE}})\&CenterDot;P_{\mathrm{RPE}}\&CenterDot;\mathrm{RPENC}\&CenterDot;\mathrm{RPE}}{H}$

T represents the time (d);

H, for representing water level (m), inputs data;

WQRPOC is slightly solubility particulate organic carbon concentration (g C/m ³), unknown quantity;

WQLPOC is active particle organic carbon concentration (g C/m ³), unknown quantity;

WQDOC is dissolved organic carbon concentration (g C/m ³), unknown quantity;

RPS is submerged plant stem biomass (g C/m ²), unknown quantity;

F _pRPRfor directly transferring to product (the 0 < F of submerged plant root _pRPR< 1), 0.3;

P _rPSgrowth rate (d for submerged plant stem ^-1), 0.8;

R _rPSrespiratory rate (d for submerged plant stem ^-1), 0.3;

L _rPSnon-breathing loss rate (d for submerged plant stem ^-1), 0.2;

JRP _rSfor submerged plant root is carried (g C/ (m to the positive carbon of submerged plant stem ²d)), 0.1;

RPR is submerged plant root biomass (g C/m ²), unknown quantity;

R _rPRrespiratory rate (d for submerged plant root ^-1), 0.1;

L _rPRnon-breathing loss rate (d for submerged plant root ^-1);

RPE is epiphyte biomass (the g C/m on submerged plant ^-2), unknown quantity;

P _rPEfor epiphyte growth rate (d ^-1), 0.75;

R _pREfor epiphyte respiratory rate (d ^-1), 0.1;

L _rPEfor the non-breathing loss rate of epiphyte (d ^-1), 0.1;

RPD is biomass (the g C/m of submerged plant stem chip ²), unknown quantity;

F _rPSDfor the loss component (0-1) of stem chip, 0.2;

L _rPDfor chip decomposition rate, 0.1;

FCR is for breathing the slightly solubility particulate organic carbon part producing, 0.2;

FCL is for breathing the active particle organic carbon part producing, 0;

FCD is for breathing the dissolved organic carbon part producing, 0.8;

FCRL is the slightly solubility particulate organic carbon loss part that non-respiration causes, 0.2;

FCLL is the dissolubility particulate organic carbon loss part that non-respiration causes, 0;

FCDL is the dissolved organic carbon loss part that non-respiration causes, 0.8;

RPSOC is submerged plant stem carbon ratio, 0.2;

RPEOC is epiphyte carbon ratio, 0.2;

WQRPOP is slightly solubility particulate organic phosphorus concentration (g P/m ³), unknown quantity;

WQLPOP is active particle organophosphorus concentration (g P/m ³), unknown quantity;

WQDOP is dissolubility organophosphorus concentration (g P/m ³), unknown quantity;

WQPO ₄for solubilised state phosphate concn (g P/m ³).Unknown quantity;

FPR is for breathing the slightly solubility particulate organic phosphorus part producing, 0.2;

FPL is for breathing the active particle organophosphorus part producing, 0;

FPD is for breathing the dissolubility organophosphorus part producing, 0.6;

FPI is for breathing the dissolubility Phos part producing, 0.2;

FPRL is the slightly solubility particulate organic phosphorus loss part that non-respiration causes, 0.2;

FPLL is the dissolubility particulate organic phosphorus loss part that non-respiration causes, 0;

FPDL is the dissolubility organophosphorus loss part that non-respiration causes, 0.6;

FPIL is the dissolubility Phos loss part that non-respiration causes, 0.2;

RPSPC is submerged plant stem phosphorus carbon ratio, 0.011;

RPEPC is epiphyte phosphorus carbon ratio, 0.011;

F _rPSPWfor absorbing PO from water column ₄component, 0.4;

WQRPON is slightly solubility particulate organic nitrogen concentration (g N/m ³), unknown quantity;

WQLPON is active particle organic nitrogen concentration (g N/m ³), unknown quantity;

WQDON is soluble organic nitrogen concentration (g N/m ³), unknown quantity;

WQNH ₄for ammonia nitrogen concentration (g N/m ³), unknown quantity;

WQNO ₃for nitrate nitrogen concentration (g N/m ³), unknown quantity;

FNR is for breathing the slightly solubility particulate organic nitrogen part producing, 0.1;

FNL is for breathing the active particle organic nitrogen part producing, 0.2;

FND is for breathing the soluble organic nitrogen part producing, 0;

FNI is for breathing the ammonia components producing, 0.7;

FNRL is the slightly solubility particulate organic nitrogen loss part that non-respiration causes, 0.1;

FNLL is the dissolubility particulate organic nitrogen loss part that non-respiration causes, 0.2;

FNDL is the soluble organic nitrogen loss part that non-respiration causes, 0;

FNIL is the ammonia components that non-respiration causes, 0.7;

RPSNC is submerged plant stem carbon-nitrogen ratio, 0.18;

RPENC is epiphyte carbon-nitrogen ratio, 0.18;

F _rPSNWfor absorbing NH4 from water column ₄and NO ₃component, 0.4;

PN _rPSfor the Preference mark of submerged plant stem to ammonium ion, 0.2;

PN _rPEfor the Preference mark of epiphyte to ammonium ion, 0.2;

(4) according to growth simulation model, predict as follows again the biomass of submerged plant in shallow lake:

1) the meteorological hydrographic data of shallow lake is inputted to constructed growth simulation model, and set algae, organic carbon, phosphorus, nitrogen, dissolved oxygen DO, submerged plant initial value and growth simulation model parameter value;

2) the dynamical mass conservation equation that growth simulation model relates to has following general formula:

$\frac{\&PartialD;C}{\&PartialD;t}=a\&CenterDot;C+b$

In formula, C is concentration, a, and b is constant;

This equation can calculate with implied format below:

$\frac{C^{n+1}-C^n}{\mathrm{\&Delta;t}}=a\&CenterDot;C^{n+1}+b$

In formula, n represents n time step;

Utilize said method to solve the growth simulation model differential equation, each model time step, all state variables are upgraded;

3) to each model time step differential equation, finally obtain the biomass of submerged plant, complete the prediction of biomass of submerged plant.

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