Method for determining appropriate water surface ratio based on water environment objectives

Abstract

The present invention discloses a method for determining an appropriate water surface ratio based on water environment objectives, including obtaining land use data and generating land use information according to the land use data; based on the land use information, determining the maximum pollutant accumulation amount C1; obtaining the pollutant accumulation rate constant C2, the scouring coefficient S1, the scouring index S2, the water quality target concentration value C of the corresponding land use s , the comprehensive pollutant degradation coefficient K, the water depth h, and the lateral inflow q; based on the Infoworks ICM model, determining the pollutant inflow rate m according to the maximum pollutant accumulation amount C1, the pollutant accumulation rate constant C2, the scouring coefficient S1, and the scouring index S2; based on the water surface ratio calculation model, determining the appropriate water surface ratio according to the pollutant inflow rate m, the water quality target concentration value C s , the comprehensive pollutant degradation coefficient K, the water depth h, and the lateral inflow q. The present invention can provide a more scientific reference index for subsequent urban planning and design and urban construction.

Description

Technical Field

[0001] The present invention relates to the technical field of urban planning, and particularly relates to a method for determining an appropriate water surface ratio based on water environment objectives. Background Art

[0002] According to relevant domestic and foreign research, the pollution carried by rainwater runoff during rainfall has become one of the main causes of water body pollution in many cities at home and abroad. It is reported that the pollution of about 60% of rivers and 50% of lakes in the United States is related to non-point source pollution mainly carried by rainwater runoff pollution. In cities where secondary sewage treatment has been achieved, about 40-80% of the annual BOD (biochemical oxygen demand or biochemical oxygen consumption) load of the receiving water body comes from rainwater runoff; research in Canada shows that rainwater runoff pollution contributes more TSS (total suspended solids content) and TKN (Kjeldahl nitrogen) to local rivers compared to point source pollution, and its contributions of COD (chemical oxygen demand) and TP are also very close to those of point source pollution sources; domestic research shows that rainwater runoff pollution is the main source of TP (total phosphorus) and TN (total nitrogen) in Baiyangdian Wetland; research in Beijing further confirms that rainwater runoff pollution has become the main reason for the deterioration of the water quality of the receiving water body. Thus, it can be seen that today when urban point source pollution has been gradually controlled, the overflow pollution and rainwater runoff pollution brought by rainwater runoff have increasingly become important and main influencing factors for the water quality of urban receiving water bodies, and sufficient attention and emphasis must be paid. In the context of ecological civilization when facing the situation of competing with water for land in urban construction, it is necessary to conduct basic research on urban water area indicators based on the appropriate water surface ratio under the water environment conditions to provide more scientific reference indicators for subsequent urban planning and design and urban construction. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a method for determining an appropriate water surface ratio based on water environment objectives, which can provide more scientific reference indicators for subsequent urban planning and design and urban construction.

[0004] The method for determining an appropriate water surface ratio based on water environment objectives according to an embodiment of the present invention includes the steps of:

[0005] Obtain land use data and generate land use information based on the land use data;

[0006] Based on the land use information, determine the maximum pollutant aggregation amount C 1 ;

[0007] Obtain the cumulative rate constant C 2 of the pollutant, the scour coefficient S 1 , the scour index S 2 and the water quality target concentration value C s, pollutant comprehensive degradation coefficient K, water depth h, and lateral inflow q;

[0008] Based on the Infoworks ICM model, according to the maximum pollutant accumulation amount C 1 , the pollutant accumulation rate constant C 2 , the scour coefficient S 1 and the scour index S 2 , determine the pollutant inflow rate m into the river;

[0009] Based on the water surface ratio calculation model, according to the pollutant inflow rate m into the river, the water quality target concentration value C s , the pollutant comprehensive degradation coefficient K, the water depth h, and the lateral inflow q, determine the appropriate water surface ratio.

[0010] According to the appropriate water surface ratio determination method based on the water environment target of the embodiment of the present invention, it has at least the following beneficial effects: The present invention uses water environment capacity calculation, hydraulic principles, and the Infoworks ICM model to propose an appropriate water surface ratio determination method based on the water environment target, which can provide more scientific reference indicators for subsequent urban planning and design and urban construction.

[0011] According to some embodiments of the present invention, based on the land use information, determine the maximum pollutant accumulation amount C 1 , including the steps:

[0012] Based on the land use information, determine the research scope of the land, and obtain the areas S of different land uses corresponding to the research scope 0 ;

[0013] Obtain the pollution index and the initial rain value corresponding to the research scope;

[0014] According to the area S 0 , the pollution index, and the initial rain value, determine the maximum pollutant accumulation amount C 1 .

[0015] According to some embodiments of the present invention, the maximum pollutant accumulation amount C 1 is equal to the product of the area S 0 , the pollution index, and the initial rain value.

[0016] According to some embodiments of the present invention, based on the land use information, determine the research scope of the land, and obtain the basin area S corresponding to the research scope. The lateral inflow q is equal to the product of the typical annual rainfall and the basin area S.

[0017] According to some embodiments of the present invention, based on the Infoworks ICM model, according to the maximum pollutant accumulation amount C1 and the pollutant accumulation rate constant C 2 and the flushing coefficient S 1 and the flushing exponent S 2 , to determine the pollutant inflow rate m, including the steps of:

[0018] Configure the attribute parameters of the Infoworks ICM model, wherein the confluence model of the Infoworks ICM model is configured as the SWMM model;

[0019] According to the maximum pollutant accumulation amount C 1 and the pollutant accumulation rate constant C 2 and the flushing coefficient S 1 and the flushing exponent S 2 , configure the SWMM model;

[0020] Determine the boundary conditions of the Infoworks ICM model and run the Infoworks ICM model to obtain the pollutant inflow rate m.

[0021] According to some embodiments of the present invention, the configuring of the attribute parameters of the Infoworks ICM model includes:

[0022] Configure the attribute parameters of the green space in the Infoworks ICM model, wherein the green space runoff type is configured as Horton infiltration, the confluence parameter is configured as 0.200, the surface type is configured as Pervious, and the confluence model is configured as the SWMM model;

[0023] Configure the attribute parameters of other construction land in the Infoworks ICM model, wherein the other construction land runoff type is configured as Fixed, the surface type is configured as Impervious, the confluence model is configured as the SWMM model, and the fixed runoff coefficient is configured as 0.6.

[0024] According to some embodiments of the present invention, the configuring of the SWMM model according to the maximum pollutant accumulation amount C 1 and the pollutant accumulation rate constant C 2 and the flushing coefficient S 1 and the flushing exponent S 2 , includes:

[0025] According to the maximum pollutant accumulation amount C 1 and the pollutant accumulation rate constant C 2, configure the Build-up attribute of the catchment area in the SWMM model, where the type of the Build-up attribute is configured as the first exponential relationship model;

[0026] According to the scouring coefficient S 1 and the scouring exponent S 2 , configure the scouring attribute in the SWMM model, where the type of the scouring attribute is configured as the second exponential relationship model.

[0027] According to some embodiments of the present invention, the calculation equation of the first exponential relationship model is: where B is the pollutant accumulation amount, C 1 is the maximum pollutant accumulation amount, C 2 is the pollutant accumulation rate constant, and t is the accumulation time.

[0028] According to some embodiments of the present invention, the calculation equation of the second exponential relationship model is: where W is the pollutant scouring amount, S 1 is the scouring coefficient, S 2 is the scouring exponent, q 1 is the net flow per unit area.

[0029] According to some embodiments of the present invention, the calculation equation of the water surface ratio calculation model is:

[0030] P = (2m - q * C s ) / (K * C s * h * S) * 100%, where m is the pollutant inflow rate into the river, q is the lateral inflow, K is the comprehensive pollutant degradation coefficient, C s is the water quality target concentration value, h is the water depth, and S is the basin area.

[0031] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0032] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0033] Figure 1 is the step flow chart of the method for determining the appropriate water surface ratio based on the water environment target in the embodiment of the present invention;

[0034] Figure 2 is the scouring process line of the method for determining the appropriate water surface ratio based on the water environment target in the embodiment of the present invention;

[0035] Figure 3 It is the process line of the annual required water surface ratio for the method for determining the appropriate water surface ratio based on the water environment target in the embodiment of the present invention. Specific embodiments

[0036] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0037] In the description of the present invention, "first", "second", etc. are only used for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0038] Please refer to Figure 1 , this embodiment discloses a method for determining the appropriate water surface ratio based on the water environment target, including steps S100, S200, S300, S400, and S500. Among them, the detailed descriptions of each step are as follows:

[0039] S100. Obtain land use data and generate land use information according to the land use data;

[0040] In this embodiment, geographic data is obtained through a GIS (Geographic Information System) platform (for example, ArcGIS), and land use information is generated according to the land use data, so as to use the land use information as a land use database to facilitate subsequent calculation of the non-point source pollutants generated by each plot.

[0041] Among them, obtaining geographic data through the GIS platform includes the steps of:

[0042] S101. Load the map file in dwg format through the GIS platform;

[0043] S102. Select and export the required elements;

[0044] S103. Adjust the topological relationship of the exported elements to obtain land use information.

[0045] In this embodiment, the map file in dwg format can be edited through CAD (Computer Aided Design) software, and the corresponding map can be edited according to different research needs of users, which is flexible and convenient to use.

[0046] S200. Determine the maximum pollutant aggregation amount C 1 , specifically including the steps:

[0047] S201. Determine the research scope of the land based on the land use information, and obtain the areas S of different land uses corresponding to the research scope. 0 ; In the land use information, there are one or more plots, and the land use nature and area S of each plot 0 may vary. According to the research requirements, determine the research scope of the land and obtain the corresponding area S 0 , for subsequent calculations.

[0048] S202. Obtain the pollution index and first flush value corresponding to the research scope.

[0049] In this embodiment, the land use natures of different research scopes may vary, and the pollution indexes corresponding to different land use natures can be obtained by referring to materials. For example, the non-point source pollution index can be determined according to the "Technical Specification for Integrated Rainwater Utilization of Low-Impact Development" (SZDB / Z 145-2015). When there is a lack of measured data, it can be calculated according to the underlying surface type according to the classification standard in Table 1, where Table 1 is the table of surface pollution prediction indexes for various land uses.

[0050]

[0051]

[0052] Table 1

[0053] To more scientifically determine the water surface ratio, this embodiment considers the first flush characteristics. The first flush value is a characteristic parameter of the first flush characteristics and can be obtained by referring to relevant materials. For example, according to the "Code for Design of Outdoor Wastewater Engineering" (GB 50014-2006), it can be obtained that when used for runoff pollution control of a separate drainage system, the storage volume of the rainwater storage tank is calculated based on the rainfall, taking 4 mm to 8 mm. In this embodiment, the value of the first flush value is 8 mm.

[0054] S203. Determine the maximum pollutant accumulation amount C 0 according to the areas S 1 of different land uses, pollution indexes, and first flush values. 1 In this embodiment, the distribution of the underlying surface is planned to calculate the first flush runoff pollution load generated by different land uses, and the first flush runoff pollution load is used as the maximum pollutant accumulation amount C1, where the maximum pollutant accumulation amount C 0 is equal to the product of the areas S

[0055] S300. Obtain the cumulative rate constant C 2 of the pollutants, 1 scouring coefficient S 2, the water quality target concentration value C of the corresponding land use s , the comprehensive degradation coefficient K of pollutants, the water depth h, and the lateral inflow q.

[0056] Among them, the cumulative rate constant C of pollutants 2 , the scour coefficient S 1 , the scour index S 2 , the water quality target concentration value C of the corresponding land use s , the comprehensive degradation coefficient K of pollutants, and the water depth h can all be obtained by referring to local relevant specifications or reference documents. Based on the land use information, the research scope of the land use is determined, and the watershed area S corresponding to the research scope is obtained. The lateral inflow q is equal to the product of the typical annual rainfall and the watershed area S. Among them, the selection method of the typical annual rainfall is as follows:

[0057] Select the years with a difference from the average not exceeding 10% according to the annual rainfall to obtain the candidate years;

[0058] Among the candidate years, based on the monthly rainfall, the monthly rainfall peak, and the distribution of rainfall intensities of each intensity, analyze according to the differences of the candidate years from the average in each factor;

[0059] Determine the typical year of rainfall and the rainfall of the typical year according to the weights of each factor.

[0060] S400. Based on the Infoworks ICM model, according to the maximum accumulation amount C of pollutants 1 , the cumulative rate constant C of pollutants 2 , the scour coefficient S 1 and the scour index S 2 , determine the pollutant inflow rate m into the river.

[0061] Step S400 specifically includes step S401 and step S402. Among them, the descriptions of step S401 and step S402 are as follows:

[0062] S401. Configure the attribute parameters of the Infoworks ICM model. Among them, configure the confluence model of the Infoworks ICM model as the SWMM ((Storm Water Management Model)) model.

[0063] In this embodiment, configuring the attribute parameters of the Infoworks ICM model includes:

[0064] S401a. Configure the attribute parameters of the green spaces in the Infoworks ICM model. Among them, the green space runoff type is configured as Horton infiltration, the confluence parameter is configured as 0.200, the surface type is configured as Pervious, and the confluence model is configured as the SWMM model;

[0065] S401b. Configure the attribute parameters of other construction lands in the Infoworks ICM model. Among them, the runoff type of other construction lands is configured as Fixed, the surface type is configured as Impervious, the confluence model is configured as the SWMM model, and the fixed runoff coefficient is configured as 0.6.

[0066] For the relevant attribute parameters of different types of runoff surfaces in the Infowroks ICM model, please refer to Table 2. In Table 2, "green space" indicates that the runoff surface is a green space, and "others" indicates that the runoff surface is other construction lands.

[0067]

[0068] Table 2

[0069] S402. Configure the SWMM model according to the maximum pollutant accumulation amount C 1 , the pollutant accumulation rate constant C 2 , the scour coefficient S 1 and the scour index S 2 .

[0070] In this embodiment, step S402 includes the steps:

[0071] S402a. According to the maximum pollutant accumulation amount C 1 and the pollutant accumulation rate constant C 2 , configure the Build-up (modeling) attribute of the catchment area in the SWMM model. Among them, the type of the Build-up attribute is configured as the first exponential relationship model. The exponential relationship model simultaneously considers the influence of pollutant accumulation and rainfall runoff on the scour process, making the calculation of pollutant accumulation and subsequent calculation of pollutant scour amount more scientific and reasonable. Among them, the calculation equation of the first exponential relationship model is: Among them, B is the pollutant accumulation amount, C 1 is the maximum pollutant accumulation amount, C 2 is the pollutant accumulation rate constant, and t is the accumulation time. In this embodiment, the pollutant accumulation rate constant C 2 takes the value of 0.4.

[0072] S402b. According to the scour coefficient S 1 and the scour index S2 Configure the scour properties in the SWMM model. Among them, the type of scour property is configured as the second exponential relationship model. The model in the form of exponential relationship takes into account the effects of pollutant accumulation and rainfall runoff on the scour process, making the calculation more scientific and reasonable. The calculation equation of the second exponential relationship model is: where W is the pollutant scour amount, S 1 is the scour coefficient, S 2 is the scour exponent, q 1 is the net flow per unit area. In this embodiment, the scour coefficient S 1 takes a value of 1.0, and the scour exponent S 2 takes a value of 0.3.

[0073] S403. Determine the boundary conditions of the Infoworks ICM model and run the Infoworks ICM model to obtain the pollutant inflow rate m into the river.

[0074] In this embodiment, COD is used as the pollution load for calculation. The boundary conditions of the Infoworks ICM model are determined as rainfall with data every five minutes in a typical year. After running the Infoworks ICM model, the amount of COD scoured every five minutes, that is, the pollutant inflow rate m into the river, is obtained. Through the operation of the Infoworks ICM model, the total annual non-point source scour amount of COD is 8473.325 kg / s, among which, Figure 2 shows the specific scour process line.

[0075] S500. Based on the water surface ratio calculation model, determine the appropriate water surface ratio according to the pollutant inflow rate m into the river, the water quality target concentration value C s , the comprehensive pollutant degradation coefficient K, the water depth h, and the lateral inflow q.

[0076] Among them, the calculation equation of the water surface ratio calculation model is:

[0077] P = (2m - q * C s ) / (K * C s * h * S) * 100%, where m is the pollutant inflow rate into the river, q is the lateral inflow, K is the comprehensive pollutant degradation coefficient, C s is the water quality target concentration value, h is the water depth, and S is the basin area. In this embodiment, through the water surface ratio calculation model, the maximum water surface ratio required for non-point source pollutant absorption throughout the year is 5.85%, concentrated at 14:35 on March 5 of the current year. Among them, Figure 3 shows the process line of the water surface ratio required throughout the year. The pollutant inflow rate m into the river in this embodiment comprehensively considers factors such as the land use nature of different land uses, the characteristics of the first rain, and the characteristics of rainfall, making the water surface ratio calculation model more scientific and reasonable.

[0078] Specifically, in the related art, the calculation method of the water area's pollution-carrying capacity only considers the pollution-carrying capacity of water body dilution, while in this embodiment, the calculation method of the water area's pollution-carrying capacity is corrected to consider a certain degree of pollutant degradation. Then the calculation equation of the water area's pollution-carrying capacity is as follows:

[0079] M = Q(C s - C 0 ) + Q p C s + KVC s - m;

[0080] In the formula, M is the water area's pollution-carrying capacity, C s is the water quality target concentration value, C 0 is the pollutant concentration value at the initial section, Q p is the discharge flow of the existing wastewater, Q is the inflow flow at the initial section, V is the water body volume, and K is the comprehensive pollutant degradation coefficient.

[0081] Assume that the water quality concentration at the starting section is consistent with the water quality control target of the water body, that is, C 0 = C s , the water area's pollution-carrying capacity is consistent with the pollutant inflow rate, that is, M = m, the discharge of the existing wastewater is consistent with the lateral inflow rate, that is, Q p = q, then V = (2m - qC s ) / KC s .

[0082] The suitable water surface area is: J = V / h, where J is the water surface area and h is the water depth.

[0083] The suitable water surface ratio is: P = J / S * 100%, where P is the water surface ratio and S is the basin area, that is, the area of the research scope.

[0084] The present invention uses water environment capacity calculation, hydraulic principles, and the Infoworks ICM model to propose a method for determining the suitable water surface ratio based on water environment objectives, which can provide more scientific reference indicators for subsequent urban planning and design and urban construction, and is conducive to calculating the water surface ratio required to absorb non-point source pollution.

[0085] The above has described the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge scope of those of ordinary skill in the art.

Claims

1. A method for determining the appropriate water surface ratio based on water environment objectives, characterized in that, it includes the steps of: Obtain land use data and generate land use information based on the land use data; Based on the land use information, determine the maximum pollutant accumulation amount C 1 ; Obtain the cumulative rate constant C of pollutants 2 , flushing coefficient S 1 , flushing exponent S 2 , the water quality target concentration value C of the corresponding land use s , the comprehensive degradation coefficient K of pollutants, water depth h and lateral inflow q; Configure the attribute parameters of the Infoworks ICM model. Among them, configure the confluence model of the Infoworks ICM model as the SWMM model; According to the maximum pollutant accumulation amount C 1 、the pollutant accumulation rate constant C 2 、the flushing coefficient S 1 and the flushing index S 2 , configure the SWMM model; Determine the boundary conditions of the Infoworks ICM model and run the Infoworks ICM model to obtain the pollutant inflow rate m into the river; Based on the water surface ratio calculation model, determine the appropriate water surface ratio according to the pollutant inflow rate m into the river, the water quality target concentration value C s , the comprehensive pollutant degradation coefficient K, the water depth h, and the lateral inflow q Among them, the calculation equation of the water surface ratio calculation model is: P = (2m - q * C s ) / (K * C s * h * S) * 100%, where m is the pollutant inflow rate into the river, q is the lateral inflow, K is the comprehensive degradation coefficient of the pollutant, C s is the water quality target concentration value, h is the water depth, and S is the basin area.

2. The method for determining the appropriate water surface ratio based on water environment objectives according to claim 1, characterized in that, Determining the maximum pollutant accumulation amount C based on the land use information 1 , including the steps of: Based on the land use information, determine the research scope of the land and obtain the area S of different land use types corresponding to the research scope 0 ; Obtain the pollution index and the first flush value corresponding to the research scope; According to the area S 0 , the pollution index and the first rain value, determine the maximum pollutant accumulation amount C 1 .

3. The method for determining the appropriate water surface ratio based on water environment objectives according to claim 2, characterized in that, The maximum accumulation amount C of the pollutants 1 is equal to the area S 0 multiplied by the pollution index and the initial rain value.

4. The method for determining the appropriate water surface ratio based on water environment objectives according to claim 1, characterized in that, Based on the land use information, determine the research scope of the land and obtain the basin area S corresponding to the research scope. The lateral inflow q is equal to the product of the typical annual rainfall and the basin area S.

5. The method for determining the appropriate water surface ratio based on water environment objectives according to claim 1, characterized in that, The configuration of the attribute parameters of the Infoworks ICM model includes: Configure the attribute parameters of the green space in the Infoworks ICM model. Among them, the green space runoff type is configured as Horton infiltration, the confluence parameter is configured as 0.200, the surface type is configured as Pervious, and the confluence model is configured as the SWMM model; Configure the attribute parameters of other construction lands in the Infoworks ICM model. Among them, the runoff type of other construction lands is configured as Fixed, the surface type is configured as Impervious, the confluence model is configured as the SWMM model, and the fixed runoff coefficient is configured as 0.

6.

6. The method for determining the appropriate water surface ratio based on water environment objectives according to claim 1 or 5, characterized in that, According to the maximum pollutant accumulation amount C 1 、the pollutant accumulation rate constant C 2 、the flushing coefficient S 1 and the flushing index S 2 , configure the SWMM model, including: According to the maximum pollutant accumulation amount C 1 and the pollutant accumulation rate constant C 2 , configure the Build-up attribute of the catchment area in the SWMM model, where the type of the Build-up attribute is configured as the first exponential relationship model; According to the scouring coefficient S 1 and the scouring exponent S 2 , configure the scouring attributes in the SWMM model, where the type of the scouring attributes is configured as the second exponential relationship model.

7. The method for determining the appropriate water surface ratio based on water environment objectives according to claim 6, characterized in that, The calculation equation of the first exponential relationship model is: B = C 1 (1 - e -C2t ), where B is the amount of pollutant aggregation, C 1 is the maximum amount of pollutant aggregation, C 2 is the pollutant accumulation rate constant, and t is the accumulation time.

8. The method for determining the appropriate water surface ratio based on water environment objectives according to claim 7, characterized in that, The calculation equation of the second exponential relationship model is: W = S 1 q 1 S2 B, where W is the pollutant wash-off amount, and S 1 is the wash-off coefficient, and S 2 is the wash-off exponent, and q 1 is the net flow per unit area.

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