CN102787582A - Method for giving early warning by building water resource model - Google Patents

Abstract

The invention provides a method for giving an early warning by building a water resource model. The water resource model is built by the following steps: (1) building a hydrodynamic model of a social economic-ecosystem according to rules of a social economic subsystem and an ecosystem water cycle which is composed of a lake/river ecological subsystem and a regional water supply subsystem; and (2) selecting a proper water quality model, quantitatively analyzing the response relation of water quality change and the influence mechanism of water quantity change in the water supply subsystem on water quality after pollutants discharged by the social economic subsystem enter the water environment, and on this basis, embedding the water environment subsystem into the hydrodynamic model of the social economic-ecosystem, to therefore build a system dynamics model capable of giving a comprehensive early warning from two aspects, i.e. water quality and water quantity. The system combines the water quality model and the system dynamics model to construct a set of water resource shortage prewarning system, thereby being beneficial to improving scientificity, effectiveness and quantitativeness.

Description

Through making up the method that the water resource model comes early warning

Technical field

The invention belongs to shortage of water resources early-warning prediction method field, particularly a kind of to pass through the method that structure water resource model come early warning of regional water resources shortage problem based on system dynamics foundation.

Background technology

In recent years, along with the aggravation of Global climate change and the increase of social economy's water, shortage of water resources has become second largest nature and the social concern that the 21 century mankind are faced after global warming.World Water Day in 2007, the United Nations just began to pay close attention to " reply water shortage " problem, and this shows that water resources crisis has become the focus that international community pays close attention to.And in China, because rainfall reduces from south to north gradually, northern area is faced with the problem of shortage of water resources for a long time, and since the seventies, the water yield in basins such as Haihe River, the Yellow River, the Liaohe River just significantly reduces, even cutout.In recent years; Under the background of global warming, historical rare arid climate has also appearred in the southwest that China's water resource is the abundantest, and river levels such as the Lancang River, the Wujiang River, Jia Lingjiang River sharply descend; Constantly break through historical low; Caused a series of problems that influence social stability and Environmental Health thus, not enough like water demand for natural service, lake eutrophication is serious etc.This shows that the shortage of water resources problem has become the key factor and a primary difficult problem in all problems of China's environmental resource.Therefore; Research and establishment one cover is taken all factors into consideration the shortage of water resources early-warning and forecast systems of the aquatic attitude of water quality and quantity; And the emergency preplan of in time formulating the reply shortage of water resources has been very urgent, and this is of great practical significance for maintain social stability, guarantee environment safety.

But; At present often more pay close attention to water yield indexs such as runoff in the water resource system, amount of precipitation and relative moisture of the soil for the research of shortage of water resources early warning; Predict the risk of shortage of water resources through analyzing its Changing Pattern, or only need water whether to be met the early warning water resources crisis through analyzing social economic system.Yet water resource system is one and society, economy; Ecology, the closely-related composite feedback system (CFS) of environment, shortage of water resources can cause the scarcity of water demand for natural service; Influence quality of water environment; Otherwise ecological disruption, environment pollution can cause falling sharply of available water resource equally, thus further exacerbate water shortage of resources situation.Therefore the response relation between the analysis-by-synthesis water yield, water quality and the aquatic attitude key element considers in the shortage of water resources early warning system it is that the ten minutes science is with necessary with water quality and aquatic attitude key element.Complexity based on water system; Some scholars have selected for use the system dynamics model of being good at research trends and complicated nonlinear system to come water security is carried out early warning; But still be to bias toward simulation and the prediction that the social economic system water yield is changed; This shows and only relies on system equation to realize that the early warning that aquatic attitude and water environment are changed is not enough to have only to add special water quality model, could realize the comprehensive pre-warning to water resources crisis.

Summary of the invention

The object of the invention is to provide a kind of through making up the method that the water resource model comes early warning, and this method combines water quality model to make up a cover shortage of water resources pre-alarming system with system dynamics model, help to improve its science, validity and quantitative property.

Technical scheme of the present invention is following:

Through making up the method that the water resource model comes early warning, at first set up the water resource model through following steps:

(1) according to the rule of social economy's subsystem and ecosystem water circulation, make up the Hydrodynamic Model of social economy-ecosystem, ecosystem water circulation is made up of lake river ecological subsystem and regional water supply subsystem;

(2) select suitable water quality model; The response relation and the water supply subsystem water yield that the pollutant that quantitative analysis social economy subsystem is discharged enters into change of water quality after the water environment change the influence mechanism to water quality; On this basis the water environment subsystem is embedded in the Hydrodynamic Model of social economy-ecosystem, thereby builds the system dynamics model that can carry out comprehensive pre-warning from water quality and quantity two aspects;

Draw the emergent regulation and control strategy of water resources crisis according to system model through following steps again: (1) obtains this regional shortage of water resources alert grade through the analog simulation to social economy-ecosystem supply and demand water yield and quality of water environment variation;

(2) simulate its influence through the adjustment relevant parameter, and combine corresponding emergent regulation and control strategy to analyze, and foundation is provided the optimization of emergent regulation and control strategy to the water resources crisis alert.

The hydrodynamic model of the said ecosystem comprises the regional water supply subsystem and needs water subsystem.

Said water supply subsystem structure is referring to Figure of description 2, and the output constraint equation is:

(1)SW(t)＝SW(t-Δt)+[I(t)+P(t)+Ed(t)-E(t)-O(t)-SS(t)-SE(t)]*Δt；

(2)TS(t)＝SW(t)+SS(t)+GS(t)。

The said water subsystem structure that needs is referring to comprising industrial water requirements, agriculture water requirement, life water requirement, water demand for natural service amount, gross water requirement in the Figure of description 3.

The water requirement constraint equation of said industrial water requirements is: (1) IV (t)=IV (t-Δ t)+IV (t-Δ t) K _I(t) * Δ t; (2) D _I(t)=IV (t) * A _I(3) IR (t)=D _I(t) * ratio1; (4) IW (t)=D _I(t) ratio2.

The need water constraint equation of said agriculture water requirement is: (1) D _A(t)=∑ Sn _*A _An(t); (2) AR (t)=D _A(t) * ratio3; (3) AW (t)=D _A(t) * ratio4.

The water requirement constraint equation of said life water requirement is: (1) NP (t)=NP (t-Δ t)+NP (t-Δ t) K _D(t) * Δ t; (2) D _D(t)=NP (t) * A _D(3) DR (t)=D _D(t) * ratio5; (4) DW (t)=D _D(t) * ratio6.

The water demand of ecological water demand constraint equation is:

The water requirement constraint equation of said gross water requirement is: D=D _I+ D _A+ D _D+ D _E-IR-AR-DR.

The constraint equation of said water environment subsystem is:

(1)SW(t)C(t)＝SW(t)C(t-Δt)+[I(t)C _I(t)+Ed(t)C _e(t)-O(t)C(t)+kC(t)SW(t)]Δt；

(2)Ed(t)＝IW(t)+AW(t)+DW(t)。

Technique effect of the present invention is:

This invention is to be goal in research with regional water resources; Start with from the feedback relationship of internal system; The water yield of analyzing the social economy's subsystem and the ecosystem supply with and and quality of water environment between response mechanism; Water resources crisis to drought condition possibly occur down carries out early warning from two aspects of water quality and quantity, for emergent regulation measure provides foundation.

Description of drawings

Fig. 1 comes the method flow sketch map of early warning for according to the invention through making up the water resource model.

Fig. 2 is a water supply subsystem structure sketch map of the present invention.

Fig. 3 is the water subsystem structural representation that needs of the present invention.

The specific embodiment

Below in conjunction with accompanying drawing the present invention is further specified.

As shown in Figure 1, through making up the method that the water resource model comes early warning, set up system through following steps:

At first set up system model through following steps:

(1) according to the rule of social economy's subsystem and ecosystem water circulation, make up the Hydrodynamic Model of social economy-ecosystem, ecosystem water circulation is made up of lake river ecological subsystem and regional water supply subsystem;

(2) select suitable water quality model; The response relation and the water supply subsystem water yield that the pollutant that quantitative analysis social economy subsystem is discharged enters into change of water quality after the water environment change the influence mechanism to water quality; On this basis the water environment subsystem is embedded in the Hydrodynamic Model of social economy-ecosystem, thereby builds the system dynamics model that can carry out comprehensive pre-warning from water quality and quantity two aspects;

Draw the emergent regulation and control strategy of water resources crisis based on system model through following steps again:

(1) through analog simulation, obtains this regional shortage of water resources alert grade to social economy-ecosystem supply and demand water yield and quality of water environment variation;

(2) simulate its influence through the adjustment relevant parameter, and combine corresponding emergent regulation and control strategy to analyze, and foundation is provided the optimization of emergent regulation and control strategy to the water resources crisis alert.

One, analyzes the circulative metabolism of water resource at the social economic system and the ecosystem; And the feedback relationship of the two, for example, the regional water supply subsystem provides water resource for social economy's subsystem; And the development of social economic system promotes the exploitation of water resource; Thereby improve the water supply capacity of regional water supply system, but the available water of regional water supply system receives the restriction of specific water demand for natural service amount, thereby make the water supply capacity of regional water supply subsystem remain on certain level.According to these inherent contacts, utilize system dynamics software Stella to set up the Hydrodynamic Model of social economy-ecosystem.Relate generally to 2 big subsystems, promptly the regional water supply subsystem needs water subsystem (comprise again that wherein industry needs water subsystem, agricultural needs water subsystem, life to need water subsystem and water demand for natural service subsystem).

T and t-Δ t are time variables in the formula, have the initial value of a simulation, such as being initial value with in January, 2000; Then t-Δ t represents the value in January, and Δ t is equivalent to a time interval, can obtain the value in February according to the value simulation in January; T just represents the value in February; And the value in March obtains according to the value in February, and therefore at this moment t-Δ t is February, and t is March.

(1) the modeling thinking of water supply subsystem

The water supply subsystem structure of having considered the surface water leakage is as shown in Figure 2.

The output constraint equation:

SW(t)＝SW(t-Δt)+[I(t)+P(t)+Ed(t)-E(t)-O(t)-SS(t)-SE(t)]*Δt (1)

TS(t)＝SW(t)+SS(t)+GS(t) (2)

In the formula, SW is a surface water capacity; I is for going into streamflow; P is an amount of precipitation; Ed is a quantity of wastewater effluent; E is an evaporation capacity; O is for going out streamflow; SS is a face of land output; SE is a leakage; GS is underground available water; Δ t is a time step; TS is a total supply.

(2) the modeling thinking of need water subsystem

The need water subsystem structure of having considered the water demand for natural service amount is as shown in Figure 3.

The water requirement constraint equation:

1) industrial water requirements (D _I)

IV(t)＝IV(t-Δt)+IV(t-Δt)K _I(t)*Δt (3)

D _I(t)＝IV(t)*A _I (4)

IR(t)＝D _I(t)*ratio1 (5)

IW(t)＝D _I(t)*ratio2 (6)

In the formula, IV is an industrial output value; K ₁Be the industrial output value growth rate; D _IBe industrial water requirements; A _IBe ten thousand yuan of industrial output value water supply volumes; Ratio1 is an industrial reuse water rate; Ratio2 is the industrial wastewater discharge rate; IR is the industrial reuse water yield; IW is an industrial wastewater.

2) agriculture water requirement (D _A)

D _A(t)＝∑S _n*A _An(t) (7)

AR(t)＝D _A(t)*ratio3 (8)

AW(t)＝D _A(t)*ratio4 (9)

In the formula, D _ABe agriculture water requirement; A _AnBe all kinds of agricultural lands water consumption; S _nBe agricultural land area; Ratio3 is agriculture recycle-water rate; Ratio4 is agriculture water-break emission index; AR (t) is the agriculture reuse water yield; AW is agriculture water-break discharge value.

3) life water requirement (D _D)

NP(t)＝NP(t-Δt)+NP(t-Δt)K _D(t)*Δt (10)

D _D(t)＝NP(t)*A _D (11)

DR(t)＝D _D(t)*ratio5 (12)

DW(t)＝D _D(t)*ratio6 (13)

In the formula, NP is a population; K _DRate of change (birth rate-death rate+rate of the moving into-rate of moving out) for population; D _DBe the life water requirement; DR is the sewage reuse amount; DW is a life quantity of wastewater effluent; Ratio5 is a life recycle-water rate; Ratio6 is life effluent discharge rate, A _DBe water supply volume per capita.

4) water demand for natural service amount (D _E)

$\mathrm{\λ}=\frac{1}{m}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\frac{E\left({\mathrm{\η}}_i\right)}{E\left({\mathrm{\ϵ}}_i\right)}---\left(14\right)$

$D_E=\mathrm{\λ}\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{D}_{\mathrm{Ei}}}{n}---\left(15\right)$

In the formula, λ is ecological water level coefficient; M is an ecological ragime index number; η _iFor changing as i in the maximum period, all years minimum ecological water bit variable; ε _iBe minimum ecological water bit variable of all years; E (η _i) be η _iMathematic expectaion; E (ε _i) be ε _iMathematic expectaion; D _EBe ecological water requirement; D _EiBe the minimum monthly water yield; N is a year umber.

5) gross water requirement (D)

D＝D _I+D _A+D _D+D _E-IR-AR-DR (16)

In the formula, D is a gross water requirement; D _IBe industrial water requirements; D _ABe agriculture water requirement; D _DBe the life water requirement; D _EBe ecological water requirement; IR is the industrial reuse water yield; AR is the agriculture reuse water yield; DR is the sewage reuse water yield.

Two, select suitable water quality model; The pollutant that quantitative analysis social economy subsystem is discharged enter into change of water quality after the water environment response relation and water supply subsystem, need the water yield of water subsystem and the ecological subsystem in lake (perhaps river) to change influence mechanism to water quality; Water quality model and regional water supply subsystem, the ecological subsystem in lake (river) and social economy's subsystem are set up contact thus; It is embedded in the Hydrodynamic Model of ecology-social economic system as the water environment subsystem, thereby builds the system dynamics model that can carry out comprehensive pre-warning from water quality and quantity two aspects.

Water environment subsystem constraint equation:

SW(t)C(t)＝SW(t)C(t-Δt)+[I(t)C _I(t)+Ed(t)C _e(t)-O(t)C(t)+kC(t)SW(t)]Δt?(17)

Ed(t)＝IW(t)+AW(t)+DW(t) (18)

In the formula: C-pollutant levels background value; CI-goes into typical pollutant concentration in the flowing water; Typical pollutant concentration in the Ce-sewage effluent; I-goes into streamflow; O-goes out streamflow; The SW-surface water capacity; K-typical pollutant sedimentation coefficient.

Three, because the present invention is conceived to the comprehensive pre-warning forecast to water resources crisis; Therefore need make alert fast judges; For emergent decision-making provides foundation, so and be not suitable for adopting the method (for example set up index system and estimate and give a mark, confirm grade) of traditional evaluation water resource safety according to score value; But in constructed model, included basically and the matter of water resource, the canonical parameter that amount is relevant; And utilize system dynamics model to set up the dependency relation between these parameters, and based on this, intend and adopt two indexs---(actual conditions according to survey region select to represent pollutant for water yield supply and demand ratio (supply and demand ratio was less than demonstration alarm in 1 o'clock) and monitoring section typical pollutant concentration; The water quality standard that is higher than national regulation shows alarm), respectively to resource lack of water and two types of water resources crisis early warning of water quality type lack of water.Concrete alert grade is formulated according to national standard and pertinent literature.

Four, according to the division of shortage of water resources warning level, (concrete parameter comprises ten thousand yuan of industrial output value water supply volumes, agriculture water consumption per mu can to adjust relevant parameter; Water supply volume per capita, industry and daily life sewage reclamation rate, industrial waste water emission factor; Pollutant levels; The water transfer inbound traffics) simulating its influence, and combine corresponding emergent regulation and control strategy to analyze, and foundation is provided the optimization of emergent regulation and control strategy to the water resources crisis alert.

The above is merely preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of within spirit of the present invention and principle, being done, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. through making up the method that the water resource model comes early warning, it is characterized in that, at first set up the water resource model through following steps:

(1) according to the rule of social economy's subsystem and ecosystem water circulation, make up the Hydrodynamic Model of social economy-ecosystem, ecosystem water circulation is made up of lake river ecological subsystem and regional water supply subsystem;

(2) select suitable water quality model; The response relation and the water supply subsystem water yield that the pollutant that quantitative analysis social economy subsystem is discharged enters into change of water quality after the water environment change the influence mechanism to water quality; On this basis the water environment subsystem is embedded in the Hydrodynamic Model of social economy-ecosystem, thereby builds the system dynamics model that can carry out comprehensive pre-warning from water quality and quantity two aspects;

Draw the emergent regulation and control strategy of water resources crisis based on system model through following steps again:

(1) through analog simulation, obtains this regional shortage of water resources alert grade to social economy-ecosystem supply and demand water yield and quality of water environment variation;

(2) simulate its influence through the adjustment relevant parameter, and combine corresponding emergent regulation and control strategy to analyze, and foundation is provided the optimization of emergent regulation and control strategy to the water resources crisis alert.

2. according to claim 1 through making up the method that the water resource model comes early warning, it is characterized in that: the hydrodynamic model of the said ecosystem comprises the regional water supply subsystem and needs water subsystem.

3. according to claim 1 and 2 through making up the method that the water resource model comes early warning, it is characterized in that: said output constraint equation is:

(1)SW(t)＝SW(t-Δt)+[I(t)+P(t)+Ed(t)-E(t)-O(t)-SS(t)-SE(t)]*Δt；

(2)TS(t)＝SW(t)+SS(t)+GS(t)。

4. according to claim 1 through making up the method that the water resource model comes early warning; It is characterized in that: the said need comprises gross water requirement in the water subsystem structure, and said gross water requirement is made up of industrial water requirements, agriculture water requirement, life water requirement, water demand for natural service amount.

5. according to claim 4 through making up the method that the water resource model comes early warning, it is characterized in that: the water requirement constraint equation of said industrial water requirements is: (1) IV (t)=IV (t-Δ t)+IV (t-Δ t) K _I(t) * Δ t; (2) D _I(t)=IV (t) * A _I(3) IR (t)=D _I(t) * ratio1; (4) IW (t)=D _I(t) * ratio2.

6. according to claim 4 through making up the method that the water resource model comes early warning, it is characterized in that: the need water constraint equation of said agriculture water requirement is:

(1)D _A(t)＝∑S _n*A _An(t)；(2)AR(t)＝D _A(t)*ratio3；(3)AW(t)＝D _A(t)*ratio4。

7. according to claim 4 through making up the method that the water resource model comes early warning, it is characterized in that: the water requirement constraint equation of said life water requirement is:

(1)NP(t)＝NP(t-Δt)+NP(t-Δt)K _D(t)*Δt；(2)D _D(t)＝NP(t)*A _D；

(3)DR(t)＝D _D(t)*ratio5；(4)DW(t)＝D _D(t)*ratio6。

8. according to claim 4 through making up the method that the water resource model comes early warning, it is characterized in that: the water requirement constraint equation of said water demand for natural service amount is:

9. according to claim 4 through making up the method that the water resource model comes early warning, it is characterized in that: the water requirement constraint equation of said gross water requirement is: D=D _I+ D _A+ D _D+ D _E-IR-AR-DR.

10. according to claim 4 through making up the method that the water resource model comes early warning, it is characterized in that: the constraint equation of said water environment subsystem is:

(1)SW(t)C(t)＝SW(t)C(t-Δt)+[I(t)C _I(t)+Ed(t)C _e(t)-O(t)C(t)+kC(t)SW(t)]Δt；

(2)Ed(t)＝IW(t)+AW(t)+DW(t)。

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