CN102663222A - Calculating method for dynamic pollution field of open water body emergent pollution accident - Google Patents

Abstract

The invention discloses a calculating method for dynamic pollution field of open water body emergent pollution accident. The method provided in the invention comprises the following steps: 1) determining area coverage the model calculates according to the position of a pollution source and basic flow field characteristics of the open water body; 2) respectively obtaining data 1, data 2, data 3, data 4 and data 5; 3) respectively inputting the data 1-5 into a software and respectively generating a corresponding data file. The experiments prove that: by applying the above technical scheme, the calculating method has advantages of using structureless trilateral and quadrilateral grids to solve for a two-dimensional or three-dimensional model and being suitable to any region's mesh dissection and solution.

Description

Open wide water body burst contamination accident and dynamically pollute a computing method

Technical field

The present invention relates to the numerical modeling method, relate in particular to and a kind ofly open wide water body burst contamination accident and dynamically pollute a computing method.

Background technology

The water environment in reservoir, lake, river course and area, river mouth is not only to the landscape ecological in zone; Simultaneously aspects such as the biocommunity in the water body, drinking water safety there is significant effects; After contamination accident takes place; Need calculate the various factors influence DYNAMIC DISTRIBUTION of contaminant density field down fast, and show intuitively, adopt certain engineering and other measures to determine the effective way that reduces pollution loss at physicochemical property then according to dynamic change of polluting the field and pollutant.Current; China's water pollution accident takes place frequently day by day; But water environment Risk-warning emergence technology is backward relatively, and urgent need will be developed relevant calculating, visual and management system, for the quick calculating of contamination accident, scenario analysis, accident assessment and antifouling decision-making provide means and foundation.

Often have characteristics following for the pollutant accident:

(1) place of burst water pollution accident is: river course, reservoir, lake, harbour, ocean etc.; The space scale of these water bodys changes greatly; Complex boundary; This computing grid that needs model to adopt is having stronger suitable ability aspect the controls such as computation bound match, mesh refinement, and most models adopts have structured grid to be difficult to flexible adaptation these have the complicated border that changes;

(2) owing to point, pollution of area source accident have sudden; There are bigger chance and mobility in the position that takes place to pollute with a data; Therefore need be given flexibly arbitrarily in the Model Calculation process, promptly after position, time and discharging modes, need the algorithm of special to change into the border form that water quality model is special procured at given pollution source on the program interface;

(3) since pollutant of a great variety, the physical-chemical parameters is different; Degraded and the reaction coefficient of all contaminations in water differs greatly; Be difficult to also there is no need in model, calculate all contaminations comprehensively; According to relational database query pollutant physical and chemical parameter and be input in the dialog box of model interface and calculate, promptly the parameter of model needs to set flexibly;

(4) result of calculation need be carried out the quick dynamic and static attitude of multi-user, many authorities (expert, administrative authority, the public) and shown and issue so that the expert is to the contamination accident high-speed decision, the public's quick understanding with withdraw etc.From These characteristics, present most water quality models and software, visual platform all do not have specifically to be directed against this specific question of the emergent decision-making of water environment and carry out special computing method and software platform research.

Summary of the invention

To the problems referred to above, the purpose of this invention is to provide and a kind ofly open wide water body burst contamination accident and dynamically pollute a detection method.

Method provided by the invention comprises the steps:

1), confirms the regional extent of Model Calculation according to the pollution source position and open wide the Field Characteristics of water body;

2) obtain data 1, data 2, data 3, data 4 and data 5 respectively;

Above-mentioned data 1 generate the quadrature quadrilateral mesh that obtains said zone for carrying out grid with the zone of 1 pair of step 1) of software earlier; Carry out the interpolation landform based on the actual measurement landform of each said grid node through software 2 again, obtain grid node data and interpolated data as data 1;

Data 1 are specifically as shown in table 1:

Table 1 two dimensional model grid and interpolated data thereof and explanation

The node number	Unit number
						13992	14425
Period	Longitude (Dec.)	Latitude (Dec.)	X coordinate (m)	Y coordinate (m)	The depth of water (m)
						…	…	…	…	…	?…

Above-mentioned data 2 are for confirming that according to polluting the time of taking place the time range of Model Calculation and Model Calculation time step obtain the Model Calculation control table, as data 2;

Said data 2 are beginning simulated time, end simulation time, computing time step-length, output time step-length, initial water level, the zero hour wind field and concluding time wind field;

Above-mentioned data 3 through paying model after the interpolation on the Model Calculation time step, as calculation of boundary conditions, are data 3 for obtaining needed water level on the section of border, zoning, flow or background water concentration time series condition, shown in table 2 and table 3:

Table 2 border file organization table

The border numbering

Affiliated branch of a river point numbering

The border title

Border HQ type

Affiliated river course numbering

Under section number

Filename

Table 3 border file data content is held form (DayongQ0707.txt)

Other boundary condition data layout is that unit is different similarly, and water level unit is m, and flux unit is m ³/ s, water quality unit are mg/l.

Above-mentioned data 4 for the concentration of the water level setting each grid node and calculate initial time, initial flow, initial flow velocity and initial pollutant to be measured as data 4;

The initial water level and the flow that calculate can adopt this model automatic Iterative to find the solution;

Above-mentioned data 5 for the position coordinates of the kind that detects pollutant to be measured, leakage point number, leak time, leakage point, leak in weight, density, the water rate of dissolution, saturation solubility, volatility and degradation rate as data 5, as shown in table 4:

Table 4 is the parameter of point source position polluter

Pollute number

Time

Longitude

Latitude

Discharging

Density

Rate of dissolution

Saturation solubility

Volatility

Degradation rate

Weight (t)

(t/m3)

Kg/(5min.Kg)

(％)

Kg/(5min.Kg)

Kg/(5min.Kg)

Model can adopt the method for minimum distance to determine contamination accident and put pairing model section according to the position coordinates of accident point;

3) adopt numerical evaluation prototype software reading of data 1-5 and dynamically calculating, obtain the concentration of pollutant to be measured of the different time of different grid nodes, thereby it is dynamic to obtain the range of influence pollutant.

Above-mentioned model can calculate in computation process according to above-mentioned data message automatically, and output corresponding calculated result, obtains the concentration of pollutant to be measured of the different time of different grid nodes, thereby the pollutant that obtains opening wide the water body range of influence is dynamic.

In said method, step 2) in, said software 1 is Gambit mesh generation software or based on the triangle subdivision and the quadrature quadrilateral program code of the Denauney algorithm of independent development; Can adopt software Tecplot to carry out interpolation;

The computing method of the interpolation landform in the said data 1 are the planar delta linear interpolation algorithm;

Position coordinates in the said data 5 is that the position coordinates in the said data 5 of latitude and longitude coordinates or square rid coordinate is latitude and longitude coordinates or square rid coordinate, and the application has made up the mutual conversion routine of two coordinates.

In the step 3), said numerical evaluation prototype software is open water pollution emergency system, kit mumber: 2011SR086425, submission date, 2010-12-26.

The equation that adopts in the above-mentioned Model Calculation is following:

Continuity equation: $\frac{\∂u}{\∂x}+\frac{\∂v}{\∂y}+\frac{\∂w}{\∂z}=0---\left(1\right)$

Water surface continuity equation: $\frac{\∂\mathrm{\η}}{\∂t}+\frac{\∂}{\∂x}\underset{H_R-h}{\overset{H_R+\mathrm{\η}}{\∫}}\mathrm{Udz}+\frac{\∂}{\∂y}\underset{H_R-h}{\overset{H_R+\mathrm{\η}}{\∫}}\mathrm{Vdz}=0---\left(2\right)$

The equation of momentum: $\frac{\mathrm{Du}}{\mathrm{Dt}}=\mathrm{Fv}-\frac{\∂}{\∂x}\left\{g(\mathrm{\η}-\mathrm{\α}\widehat{\mathrm{\ψ}}+\frac{P_a}{{\mathrm{\ρ}}_0})\right\}-\frac{g}{{\mathrm{\ρ}}_0}\underset{z}{\overset{H_R+\mathrm{\η}}{\∫}}\frac{\∂\mathrm{\ρ}}{\∂x}\mathrm{Dz}+\frac{\∂}{\∂z}\left(K_{\mathrm{Mv}}\frac{\∂u}{\∂z}\right)+F_{\mathrm{Mx}}=0---\left(3\right)$

$\frac{\mathrm{Dv}}{\mathrm{Dt}}=\mathrm{fu}-\frac{\∂}{\∂y}\left\{g(\mathrm{\η}-\mathrm{\α}\widehat{\mathrm{\ψ}}+\frac{P_a}{{\mathrm{\ρ}}_0})\right\}-\frac{g}{{\mathrm{\ρ}}_0}\underset{z}{\overset{H_R+\mathrm{\η}}{\∫}}\frac{\∂\mathrm{\ρ}}{\∂y}\mathrm{dz}+\frac{\∂}{\∂z}\left(K_{\mathrm{mv}}\frac{\∂v}{\∂z}\right)+F_{\mathrm{my}}=0---\left(4\right)$

The salinity transport equation: $\frac{\mathrm{DS}}{\mathrm{Dt}}=\frac{\∂}{\∂z}\left(K_{\mathrm{Sv}}\frac{\∂S}{\∂z}\right)+F_s---\left(5\right)$

Temperature transport equation:

The transport equation of polluter: $\frac{{\mathrm{DC}}_i}{\mathrm{Dt}}=\frac{\∂}{\∂z}\left(K_{\mathrm{CV}}\frac{{\∂C}_i}{\∂z}\right)+F_{\mathrm{Ci}}+F_i---\left(7\right)$

The variable declaration of above-mentioned formula:

(x, y, z) Cartesian coordinate, the m of unit;

(φ, λ) longitude and latitude;

The t time, the s of unit;

H _RThe reference levels of Z coordinate (MSL);

The η free face m of elevation unit;

H (x, y) river course or river mouth depth of water m;

water velocity; comprises (u; V, w) speed component;

comprises (x; Y, z) component;

The f Coriolis factor, the s of unit ^-1

G acceleration of gravity, the ms of unit ^-2

m of tidal potential unit;

The effective earth elasticity factor of α effective Earth elasticity factor (=0.69; Foreman et al., 1993)

Water-mass density comprises the density that is caused by salinity and silt mixed solution etc., ρ ₀=1025kg.m ³

P _a(x, y, t) water body atmospheric pressure freely, the N.m of unit ^-2

S, T salinity of water (psu) and temperature (℃)

C _iI pollutant matter concentration, for different materials, its unit is different

K _MvSticking coefficient (the m in vertical whirlpool ²s ^-1)

K _Sv, K _HvSticking coefficient (the m in the vertical whirlpool of salinity and heat ²s ^-1)

K _CVBe the sticking coefficient (m in the vertical whirlpool of polluter ²s ^-1)

F _Mx, F _My, F _s, F _hWater body, salinity and temperature levels diffusion term;

F _Ci, F _iBe respectively and transport the physical reaction item and outer source item of material;

The technical scheme that the present invention adopts is following:

In order to consider that effectively the water with complex boundary water body pollutes the rapid transportation process, carry out rapid solving through making up structureless two dimensional model, this finds the solution pattern can consider to reach under the unsteady flow field action pollutant transport process under the different discharging modes effects;

Owing to may adopt different coordinate-system (longitudes and latitudes in the actual computation process; Xy coordinate etc.); Therefore developed longitude and latitude and xy coordinate transformation model based on Gauss-Ke Lvge method; And be integrated among the system, to satisfy the problem of finding the solution of different coordinates system, increase the dirigibility of calculating and reduce artificial workload;

This paper model has fully taken into account the dirigibility of calculating, and all is the grid of non-structure form, therefore calculates to have good versatility;

Of the present inventionly experiment showed, that owing to take above technical scheme, it has the following advantages: 1, two or three-dimensional model adopt non-structure triangle and four limit type grids to find the solution, the mesh generation that can adapt to the arbitrary face territory equally with find the solution; 2, model can adapt to various complicacies burst point and pollution of area source accident, pollutant parameter and actual physical and chemical factor flexible configuration and simulate; 3, develop the pollution field and dynamically transport visualization system and corresponding systematic parameter configuration-system platform; 4, the invention provides a kind of efficiently, complicated river water environmental method for numerical simulation fast and accurately, can be widely used in complicated river water environmental burst contamination accident numerical simulation (or " simulation " or " prediction " or " meet an urgent need and predict " etc.) process.This method can carry out comprehensively the burst contamination accident of the water environment of various complicated water bodys, efficiently, analog computation accurately.

Description of drawings

Fig. 1 is the computing system process flow diagram

Fig. 2 is two dimensional model zoning and computing grid figure thereof

The Flow Field Distribution that Fig. 3 calculates for two dimensional model

Fig. 4 is position, different fixing monitoring point

Fig. 5 is the change procedure that pollutant levels are calculated in position, different fixing monitoring point

Fig. 6 is for judging the range of influence and the space-time dynamic change procedure thereof of polluter

A dynamic changing process (coordinate unit is m among the figure) is polluted in the point-source pollution source that Fig. 7 calculates for zero-dimensional model under the even velocity of flow field action

Embodiment

Employed experimental technique is conventional method like no specified otherwise among the following embodiment.

Used material, reagent etc. like no specified otherwise, all can obtain from commercial sources among the following embodiment.

Because it possibly be zones such as river, lake, river mouth, ocean that the water body of contamination accident takes place, the key element of finding the solution is a lot, so the application is divided into six kinds of discharging modes and finds the solution.

Following embodiment is convenient to understand better the present invention, but does not limit the present invention.Experimental technique among the following embodiment like no specified otherwise, is conventional method.

Embodiment 1, two dimensional model detect

System implementation relates generally to that selection and grid generation, landform interpolation, Model Calculation period and the step-length of survey region are confirmed, the characteristic parameter of the input of boundary condition, starting condition, leakage pollution material is confirmed, coordinate transformation, Model Calculation and output as a result thereof etc.; The process flow diagram that relates to is seen Fig. 1, is that example is set forth technical scheme of the present invention with zone, Eight Diagrams continent, Nanjing xylene pollution to section, Nanjing and THE LOWER YANGTZE VALLEY influence thereof below.

Suppose that Nanjing dragon Xiang fluid chemical transit godown contains limit company tank field toluene leakage accident, some longitude and latitude in place where the accident occurred is: 118.81 32.24, and emission of substance characteristic: toluene 60t, instantaneous discharging

With the tank field toluene tank is example.In a single day the Tank Farm material is revealed, surpass cofferdam, tank field and 500m ³The capacity in accident waste liquid storage pond is perhaps controlled ineffectively, and pollutant is as sneaking into sewage network; Promptly possibly directly get into water utilities sewage treatment plant of victory section, will increase sewage treatment plant load, cause sewage treatment plant's waste water can not qualified discharge; Sewage body-the Changjiang river is received in pollution, causes the partial water body pollution.

1, confirms the zoning scope

Confirm the zoning scope according to pollution source position and the essential characteristic of opening wide the water body flow field.

The general smooth-going area of current of selecting is imported and exported in the zoning; Be beneficial to the given of boundary condition; And the zoning need comprise the range of influence of disposal of pollutants, and to the discharging of Nanjing Craft in Chemical Industrial Area pollution source, the research range of selection is Nanjing section master section, the Changjiang river; Length is about 40km, and regional extent is as shown in Figure 2;

2, obtain data 1, data 2, data 3, data 4 and data 5 respectively;

1) acquisition of data 1

Mesh generation: the mesh generation of model mainly adopts Gambit mesh generation software or carries out the grid generation based on the triangle subdivision of the Denauney algorithm of independent development with quadrature quadrilateral program code; The Changjiang river Nanjing section quadrature quadrilateral mesh that generates is seen Fig. 2; 14425 of grid cell numerical digits, node number are 13992;

Landform interpolation: the topography profile that can grid node in the computational process based on the actual measurement landform interpolation of collecting; Lack or require under the quick The conditions of calculation like terrain data; Can suppose the landform of model meshes node based on the calculating experience; In this research case, adopt the terrain data of actual measurement to carry out interpolation (software that also uses is Tecplot), the algorithm use of interpolation is carried out the interpolation landform based on the planar delta linear interpolation algorithm of triangle gridding; In conjunction with the distribution of the initial water surface, the initial depth of water of the grid node that obtains distributes and profile data is respectively shown in the table 1;

Table 1 two dimensional model grid and interpolated data thereof and explanation

The node number	Unit number
						13992	14425
Period	Longitude (°)	Latitude (°)	X coordinate (m)	Y coordinate (m)	The depth of water (m)
						…	…	…	…	…	?…
60	118.725262	32.094265	39662869.30	3553610.00	22.95
						61	118.724999	32.094368	39662844.30	3553621.00	22.43
62	118.724734	32.094462	39662819.10	3553631.00	20.34
						63	118.724466	32.094555	39662793.60	3553641.00	18.82
64	118.724197	32.094649	39662768.10	3553651.00	18.05

65	118.723924	32.094743	39662742.10	3553661.00	17.77
						66	118.723655	32.094855	39662716.50	3553673.00	18.23
67	118.723385	32.094958	39662690.80	3553684.00	18.91
						68	118.723113	32.095070	39662665.00	3553696.00	19.71
69	118.722852	32.095199	39662640.10	3553710.00	20.56
						70	118.722586	32.095311	39662614.80	3553722.00	21.44
71	118.722318	32.095423	39662589.30	3553734.00	22.35
						72	118.722046	32.095544	39662563.40	3553747.00	23.31
73	118.721772	32.095656	39662537.30	3553759.00	24.34
						74	118.721494	32.095777	39662510.90	3553772.00	25.53
75	118.721215	32.095898	39662484.30	3553785.00	26.55
						76	118.720934	32.096019	39662457.60	3553798.00	27.44
77	118.720653	32.096149	39662430.80	3553812.00	28.05
						78	118.720371	32.096279	39662403.90	3553826.00	28.52
79	118.720087	32.096409	39662376.90	3553840.00	28.95
						80	118.719804	32.096548	39662349.90	3553855.00	29.15
Unit number	Count in the unit	Node	1	Node 2	Node 3							Node 4
						…	…	…	…	…	…
7222	4	7464	7513	7514	7465
						7223	4	7465	7514	7515	7466
7224	4	7466	7515	7516	7467
						7225	4	7468	7517	7518	7469
7226	4	7469	7518	7519	7470
						7227	4	7470	7519	7520	7471
7228	4	7471	7520	7521	7472
						7229	4	7472	7521	7522	7473
7230	4	7473	7522	7523	7474
						7231	4	7474	7523	7524	7475
7232	4	7475	7524	7525	7476
						7233	4	7476	7525	7526	7477
?…	…	…	…	…	…

2), the acquisition of data 2

Carrying out Model Calculation period and step-length confirms: according to polluting time range that the time of taking place confirms Model Calculation and Model Calculation time step as data 2.

Scope computing time of model need comprise the time range of polluting generation and effective influence subsequently thereof; And substantial connection is arranged with the computing velocity of model; Section computing time of model is 1 month; In input file inputSource.txt, the file main contents are interpreted as (time range of Model Calculation and Model Calculation time step data):

Beginning simulated time: 2007-01-03 08:00:00

The end simulation time: 2007-01-04 08:00:00

Step-length computing time (Sec): 300

Output time step-length (Sec): 3000

Initial water level (Huanghai Sea elevation m): 4.3

The wind field zero hour (m/s, degree): 5.0,90

Concluding time wind field (m/s, degree): 5.0,90

3), the acquisition of data 3

Carrying out boundary condition confirms: obtain needed water level on the section of border, zoning, flow or background water concentration time series condition, through paying model as calculation of boundary conditions after the interpolation on the Model Calculation time step, be data 3.

Boundary condition comprises current boundary condition and water quality background values boundary condition; Boundary condition is mainly the concentration of water level, flow and all kinds of background pollution materials; Its main data are time series processes; Because different its boundary condition numbers of zoning is different with type, the data structure of employing is as shown in table 2, and respective data storage is in Boundary point structure data.txt.In last each file of row storage in the table 2.Wherein first station flow boundary condition form is as shown in table 3, and other boundary condition data layout is that unit is different similarly, and water level unit is m, and flux unit is m ³/ s, water quality unit are mg/l:

Table 2 border file organization table

The border numbering	The border title	Border HQ type	Filename
					1	The Nanjing import	2	NanjingQC.txt
2	Hereditary property continent head	1	ShiYezhouHC.txt
				3	Zhu Jia mountain lock	2	ZhujiashanDamC.txt
4	Ma Chahezha	2	MaChaRivDamQC.txt
				5	The Yue Zi river course	2	YuziRivQC.txt
6	Beam village flow	2	LiangzhuangQC.txt
				7	New people's flow	2	XinMingQC.txt
8	Small rowboat mouth flow	2	HuaKouZiQC.txt
				9	The Chunhe river mouth	2	ChuriverQC.txt

1 representation level process identifier in the HQ type in the table 2,2 represent the discharge process sign.

Table 3 border file data content is held form (DatongQ0707.txt)

4) acquisition of data 4

The concentration of setting water level that each grid node calculates initial time, initial flow, initial flow velocity and initial pollutant to be measured is as data 4;

The input of starting condition: the input of starting condition; Starting condition comprises conditions such as initial water level, flow, flow velocity and pollutant levels thereof; The model system that the application set up is directly given in model system according to actual conditions, promptly is directly to pay initial value in two dimensional model.

5) acquisition of data 5

The parameter of point source position polluter is confirmed: detect kind, leakage point number, leak time, the leakage point of pollutant to be measured position coordinates, leak that rate of dissolution, saturation solubility, volatility and degradation rate are as data 5 in weight, density, the water, data 5 main characteristics with actual contamination accident are confirmed.

Need be in model system to polluter kind (being assumed to nitrobenzene), rate of dissolution, saturation solubility (%), volatility Kg/ (s.Kg) etc. need carry out data declaration in emission point number, drain time, position coordinates, discharging weight, density, the water.Its data storage is in inputsourcedata (PointWq) .txt.Table 4 is seen in concrete being provided with, and the parameter in the table is mainly obtained through the corresponding document in the inquiry system.

Table 4 is the parameter of point source position polluter

Wherein, Under the usual conditions; China's earth-fixed co-ordinate system mainly adopts square rid, latitude and longitude coordinates system etc., under large-scale map system, mainly adopt Gauss-Ke Lvge to divide 3 degree to be with and carry out projection with 6 degree; In order to unite to different coordinate systems; Having write the mutual transformant MODEL C # class of dividing following two coordinate systems of band projection effect based on Gauss Kru&4&ger projection separately, and be integrated in to be implemented in the system and realize directly in the longitude and latitude map that carrying of point-source pollution object location longitude and latitude coordinate is converted into the square rid coordinate, can be latitude and longitude coordinates with the square rid coordinate transformation also in the process of data visualization simultaneously.

3, model running

It is that core is found the solution that two dimensional model mainly adopts the non-structure current of foundation and transport of substances mathematical model thereof; The current discrete method is the method for finite difference and finite element combination; Computing grid is non-structure triangle and quadrilateral mesh; The transport of substances equation adopts high precision TVD form to disperse and finds the solution, and the water quality calculating section of model adopts and writes based on the water quality principle of Wasp.

The Hydrodynamic Model that the water environment model of this project is adopted is the open source code model and model is carried out part revise; Further develop water quality on this basis and calculated model program, realized the given and automatic setting of boundary condition and pollutant emission position.Because the model meshes system that is adopted is the non-structure grid; Therefore model has bigger advantage aspect the complex boundary match, and the convective term of finding the solution the equation of momentum adopts Euler-Lagrangian algorithm, and the stability of algorithm better; Can so that computing time step-length break through the restriction of CFL＜1; Improved counting yield, the pollutant of model is found the solution and is adopted the implicit expression difference of facining the wind to find the solution, and has stronger stability.

When conditions and datas such as the needed grid of above-mentioned model, model interpolation, various border, initial, point source are set completion in system after; And generate corresponding data file; Then just can moving model; The Craft in Chemical Industrial Area in Nanjing, it is about 30 minutes that two dimensional model calculates when left and right sides materializing procedure needed computing machine in 10 days.

The data 1-5 difference input value computation model software that step 2 obtains (is opened the water pollution emergency system; Kit mumber: 2011SR086425; Submission date; 2010-12-26) reading of data 1-5 can carry out the dynamic calculation that contamination accident is polluted the field, and model can calculate according to above-mentioned data message in computation process automatically, and output corresponding calculated result; Obtain the concentration of pollutant to be measured of the different time of different grid nodes, thus obtain the accident impact zone contaminant density field dynamically.

Hydrodynamic force that above-mentioned two dimensional model calculates and polluter result of calculation, the emission behaviour of polluter is divided into: the concentration field change procedure of 20 tons of toluene of limit, the Changjiang river bank discharging; The Tidal Flow that has provided Model Calculation from Fig. 3 distributes,

From the result of calculation polluter as getting into the Changjiang river; Its discharge process has the advantages that bank transports; Can't diffuse to whole river surface, because the Changjiang river flow rate of water flow is bigger, polluter can be degraded by the regional also rapid dilution in rapid transportation to downstream; Model can calculate the spatial and temporal distributions (like Fig. 3) of water level, velocity field; Provided position, different fixing monitoring point (particular location is as shown in Figure 4) among Fig. 5 and calculated the change procedure of pollutant levels, from figure, can find out peak value time of arrival of polluter and attenuation process subsequently thereof clearly, can further obtain its hazard level to the pollutant concentration standard.Further can judge the range of influence and the space-time dynamic change procedure thereof of polluter from Fig. 6.As can be seen from the figure, because the Yangtze River Water face width is shallow, polluter can not failed to move on in the opposite bank and go, and is therefore less to the influence on opposite bank, can adopt 0 dimension model to carry out tentative calculation simultaneously in the area of no data yet, and its result of calculation is as shown in Figure 7.

The concentration change in time and space process of diverse location polluter, its result of calculation is seen (like Fig. 3-5).

The main computing method and the step of embodiment 2, zero-dimensional model

Under the situation about lacking for the quick estimation of needs and border condition data such as landform, water level and flow, can consider to use zero-dimensional model to calculate fast.The employing of model continues to calculate with instantaneous point source formula.

(1) cardinal principle of model:

Instantaneous source two-dimensional diffusion model equation is:

$\frac{\∂c}{\∂t}+U\frac{\∂c}{{\∂x}_1}=D_{11}\frac{{\∂}^{2}c}{{{\∂x}_1}^2}+D_{22}\frac{{\∂}^{2}c}{{{\∂x}_2}^2}---(3-1)$

Being solved to of this equation: $c({\mathrm{<figure-callout\; id="1"\; label="x"\; filenames="HDA0000140608150000022.png,HDA0000140608150000023.png"\; state="\{\{state\}\}">x</figure-callout>}}_1,x_2,t)=\frac{\mathrm{<figure-callout\; id="4"\; label="M"\; filenames="HDA0000140608150000022.png,HDA0000140608150000023.png"\; state="\{\{state\}\}">M</figure-callout>}}{\sqrt{4\mathrm{\&pi;}{D}_{11}{D}_{22}}}\mathrm{Exp}[-\frac{{(x_1-U_t)}^2}{4D_{11}t}-\frac{x_2^2}{4D_{22}t}]---(3-2)$

C is a material concentration in the formula, x ₁, x ₂Be respectively x, the coordinate of y both direction, D ₁₁, D ₂₂Be respectively x, the turbulence diffusion coefficient of y both direction, M is material mass (kg);

For continuous source two-dimensional diffusion computing formula, its computing formula form is:

$c({\mathrm{<figure-callout\; id="1"\; label="x"\; filenames="HDA0000140608150000022.png,HDA0000140608150000023.png"\; state="\{\{state\}\}">x</figure-callout>}}_1,x_2)=\frac{\stackrel{\&CenterDot;}{M}}{\mathrm{<figure-callout\; id="4"\; label="U"\; filenames="HDA0000140608150000022.png,HDA0000140608150000023.png"\; state="\{\{state\}\}">U</figure-callout>}\sqrt{4\mathrm{\&pi;}{\mathrm{<figure-callout\; id="1"\; label="Dx"\; filenames="HDA0000140608150000022.png,HDA0000140608150000023.png"\; state="\{\{state\}\}">Dx</figure-callout>}}_1/U}}\exp [-\frac{x_2^2\mathrm{<figure-callout\; id="4"\; label="U"\; filenames="HDA0000140608150000022.png,HDA0000140608150000023.png"\; state="\{\{state\}\}">U</figure-callout>}}{4{\mathrm{Dx}}_1}]---(3-3)$

is line source intensity in the formula, the quality that the level per unit length diffused out in the unit interval.The scope of application of formula is the situation of calculating

, and this moment, CONCENTRATION DISTRIBUTION tended towards stability.The result of calculation of formula is just set up.

Model is divided into x in compiling procedure, the y both direction, and (x0, y0), the distance of its diffusion is the position with respect to point source in the position of point source.Calculate the change in concentration under the different convection current diffusions constantly of its point source.

(2) mesh generation of zoning and the net region depth of water: the mesh generation method that it is main is identical with the mesh generation method of two dimensional model, and especially 0 dimension model does not need detailed landform, only need provide the average depth of water in zoning and get final product;

(3) pollution source set positions: its establishing method is identical with the one dimension network of waterways and two dimensional model; Do not consider sinking, the chemical reaction of polluter at the polluter of 0 dimension model;

(4) boundary condition is given: need provide regional velocity field in the zero-dimensional model, given generally speaking average gets final product, and the flow field that also can directly call two dimensional model calculating makes that calculating is more reasonable;

(5) calculate operation and result thereof: after configuring above-mentioned various conditions; Get final product moving model; Suppose that a point-source pollution material is in the uniform flow; The different diffusion and the dilution of polluter constantly that calculate of model are illustrated in fig. 7 shown below, and as can be seen from the figure, the zero dimension computation model can go out the convection current and the diffusion process of polluter; Can set x in the model, the coefficient of diffusion of y direction is to reflect the difference of material in the turbulent fluctuation diffusion of main flow and cross-current direction.

Brief summary:

Because the model of exploitation has versatility; And be applied to the actual computation that the Dalian Oil spills is polluted; And provide technology to support to the evaluation that influences of marine environment for Chinese Ministry of Environmental Protection and 863 environmental impact assessment expert opinion Dalian Oil spills with calculating; The technology that the while patent relates to also is used for the migration and the diffusion process of supposition pollutant in reservoir area under the Three Gorges Reservoir scheduling effect, and the calculating of the pollution field of the steep River Reservoir in Tangshan has application promise in clinical practice.

Claims (2)

1. a network of waterways area burst contamination accident is polluted the detection method of a dynamic change, comprises the steps:

1) confirms the network of waterways regional extent of Model Calculation according to pollution source position and river course space distribution;

2) obtain data 1, data 2, data 3, data 4 and data 5 respectively;

Said data 1 generate the quadrature quadrilateral mesh that obtains zone, the said network of waterways for carrying out grid with the zone, the network of waterways of 1 pair of step 1) of software earlier; Carry out the interpolation landform based on the actual measurement landform of each said grid node through software 2 again, obtain grid node data and interpolated data as data 1;

Said data 2 are for confirming that according to polluting the time of taking place the time range of Model Calculation and Model Calculation time step obtain the Model Calculation control table, as data 2;

Said data 2 are beginning simulated time, end simulation time, computing time step-length, output time step-length, initial water level, the zero hour wind field and concluding time wind field;

Said data 3 through paying model after the interpolation on the Model Calculation time step, as calculation of boundary conditions, are data 3 for obtaining needed water level on the section of border, zoning, flow or background water concentration time series condition;

Said data 4 for the concentration of the water level setting each grid node and calculate initial time, initial flow, initial flow velocity and initial pollutant to be measured as data 4;

Said data 5 for the position coordinates of the kind that detects pollutant to be measured, leakage point number, leak time, leakage point, leak in weight, density, the water rate of dissolution, saturation solubility, volatility and degradation rate as data 5,

3) adopt the numerical evaluation prototype software to read above-mentioned 1) the data 1-5 that obtains and dynamically calculating, obtain the concentration of pollutant to be measured of the different time of different grid nodes, thereby the pollutant that obtains network of waterways system is dynamic.

2. the method for claim 1 is characterized in that:

Step 2) in, said software 1 is Gambit mesh generation software or based on the triangle subdivision and the quadrature quadrilateral program code of the Denauney algorithm of independent development; Interpolation can adopt software Tecplot;

The computing method of the interpolation landform in the said data 1 are the planar delta linear interpolation algorithm;

Position coordinates in the said data 5 is latitude and longitude coordinates or square rid coordinate;

In the step 3), said numerical evaluation prototype software is open water pollution emergency system, kit mumber: 2011SR086425.

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