Simulation method for riverway hardening in surface water-underground water coupling model

Abstract

The invention relates to a method for simulating riverway hardening in a surface water-underground water coupling model. The technology comprises the following steps: constructing a basic area surface water-underground water coupling model; carrying out specificity expression on the river channel hardening condition; the interaction process of water flow in the river channel and peripheral surface water is expressed; according to different types of hardening conditions of the riverway, the interaction process of water flow in the riverway and surrounding underground water is expressed; and based on the basic area surface water-underground water coupling model, coupling the steps 2, 3 and 4 to realize the dissimilatory simulation of the river hydrodynamic process under different river hardening category conditions. The method has the technical effects that the hydrological interaction process of the river surface water and the underground water is supplemented and perfected by carrying out differential expression on the river hardening condition and considering the hydrological processes under different hardening conditions, so that the model is more applicable, the interaction water quantity of the river surface water and the underground water can be accurately calculated, and the water quality of the river surface water and the underground water is improved. And the influence of groundwater supply and extraction on surface water and ecological environment can be evaluated.

Description

Technical Field

[0001] The present application relates to the technical field of a method for simulating river channel hardening in a model, and in particular to a method for simulating river channel hardening in a surface water-groundwater coupling model. Background Art

[0002] In the field of water resources management and ecological environment protection, the interaction between surface water and groundwater is crucial to maintaining ecological balance and sustainable use of water resources. Groundwater is part of the subsurface hydrological system, while surface water includes water bodies such as rivers, lakes and wetlands. Understanding and simulating the interaction between these water bodies is crucial for the rational management of water resources, drought prevention, flood control and ecological environment protection. Traditionally, researchers have used numerical models to simulate the interaction between surface water and groundwater. These models usually treat surface water and groundwater separately without coupling them well, resulting in inaccurate simulation results. In addition, the hardening of river channels varies in different regions, and traditional models find it difficult to fully consider the impact of this factor on hydrological processes. Therefore, it is necessary to develop a method that can couple surface water and groundwater models and consider hydrological processes under different hardening conditions. This method will help to more accurately simulate and understand the interaction between surface water and groundwater and improve the efficiency and effectiveness of water resources management and ecological environmental protection. This patent proposes a simulation method for river channel hardening in a surface water-groundwater coupling model. Using this method, the hardening conditions of different river channels, the interaction between the water in the river section and the surrounding groundwater and the amount of interactive water can be accurately calculated, which supplements and improves the hydrological process of river channel water and surrounding surface water and groundwater. Summary of the invention

[0003] In order to accurately calculate the interaction between river water and surrounding groundwater under different river hardening conditions, the present application provides a simulation method for river hardening in a surface water-groundwater coupling model. The present application provides a method for simulating river channel hardening in a surface water-groundwater coupling model, which adopts the following technical solutions: The technology includes: Step 1: Construct a basic regional surface water-groundwater coupling model; Step 2: Differentiate and express the hardening of the river channel; Step 3: Express the interaction process between the water flow in the river and the surrounding surface water; Step 4: According to the different types of hardening of the river channel, express the interaction process between the water flow in the river channel and the surrounding groundwater; Step 5: Based on the basic regional surface water-groundwater coupling model, couple steps 2, 3, and 4 to achieve differentiated simulation of river hydrodynamic processes under different river hardening categories; Through the above scheme, the river channel hardening material is expressed in the surface water-groundwater coupling model, new river channel material parameters are added, the hydrological process is supplemented and improved, and the interaction between the river channel hardening materials and the surrounding surface water and groundwater is accurately calculated. Then, the improved model can be used to evaluate the impact of river channel hardening on regional surface water and groundwater. Preferably, the specific content of step one is to use Intelliway-SSIM to build a surface water-groundwater coupling model. a. Simplify the boundaries of the study area and the rivers within the area to a reasonable level; b. Divide the study area into triangular grids of varying sizes and divide the river channel into rectangular / trapezoidal grids of varying lengths; c. Use DEM data, soil data, stratum data, land use data, and meteorological data to give triangular meshes different attributes; d. Use the river width and depth data from the survey to assign different attributes to the rectangular / trapezoidal grids; Preferably, the specific content of step 2 is to express the river channel hardening conditions in a differentiated manner, including ecological river channel, one-side light, two-side light and three-side light. a. Through field investigation, the materials of the river in the study area are divided into four categories: ecological river (River-matype=0) means that the river is not hardened, one-sided light (River-matype=1) means that one side of the riverbed is made of hard material, two-sided light (River-matype=2) means that both sides of the riverbed are made of hard material, and three-sided light (River-matype=3) means that both the side and bottom of the riverbed are made of hard material; b. Add river material expression parameters, River-matype, to the model; c. Fill 0, 1, 2, and 3 into the model input file to complete the expression of the heterogeneity of the river channel in terms of hardening; Preferably, the specific content of step three is to express the interaction process between the water flow in the river channel and the surrounding surface water. When the water level of the river channel is higher than the sum of the river bank height and the depth of the adjacent surface water, the river channel water overflows the river channel and flows to the adjacent surface. On the contrary, when there is adjacent surface water and it is higher than the river channel water level, the adjacent surface water flows into the river channel. The specific formula is as follows: Relative water level of the river ( )>the sum of river bank height (the height from river bottom to ground surface) and the depth of adjacent surface water ( ): Relative water level of the river ( )<the sum of river bank height and adjacent surface water depth( ): in: is the Verriuli coefficient, which represents the effect of weir geometry and flow conditions; is the effective length of the weir, i.e. the cross-sectional length of the weir through which the water flows, here the length of the river reach; It is the vertical distance between the river water level and the surface water level; n is the flow index. Preferably, the specific content of step 4 is to express the interaction process between the river channel and the surrounding groundwater according to the hardening condition of the river channel, wherein: Ecological river (River-matype=0): The water in the river can infiltrate into the riverbed and the soil beside it, and at the same time, the water in the riverbed and the soil beside it can also infiltrate to replenish the water in the river; One-sided light river (River-matype=1): The river water and the surrounding groundwater can interact at non-hard materials, but the river water and the surrounding groundwater cannot interact at hard materials; Two-sided smooth river (River-matype=2): Similarly, only the river flow at the non-hard material can interact with the surrounding groundwater; Three-sided bare river (River-matype=3): Since the three sides are made of hard materials, the river flow cannot interact with the groundwater; The formula for interaction calculation is as follows: in: is soil moisture; is the soil water flux; is the absolute elevation; K is soil hydraulic conductivity; is the river water level; is the riverbed elevation; is the soil pressure potential; It is the difference between the river water level and the surrounding groundwater level. Preferably, the specific content of step five is to couple steps two, three and four based on the basic regional surface water-groundwater coupling model to achieve the differentiated simulation of river hydrodynamic processes under different river hardening categories and the simulation of their impact on the surrounding surface water and groundwater hydrological processes, which includes the following steps: Step 1: T=0, receiving model initialization data to form the initial water level condition of the basin; Step 2: Calculate the runoff generation and convergence process on land, the interaction process between surface runoff and groundwater, the interaction process between land grids, and the evapotranspiration process according to the initial conditions of the model, and obtain the surface water level and groundwater level of each triangular grid along the river; Step 3: Calculate the interaction between the river channel and the surrounding surface water. When the water level in the river channel is higher than the surface water level, the river channel water flows to the surface, and vice versa. Step 4: Calculate the interaction between the river channel and surrounding groundwater according to the material conditions of the river channel; Step 5: T=T+1, determine whether T is equal to Tend, where Tend is the simulation end time. If T≠Tend, repeat steps 2 to 4 based on the new data. Otherwise, the model calculation ends and the interaction results are output. The beneficial effects of the present invention are: 1. By differentially expressing the hardening conditions of the river channel, the hydrological process under different hardening conditions can be considered, making the model more applicable; 2. By calculating the interaction between surface water and groundwater, it is helpful to evaluate the impact of groundwater recharge and extraction on surface water and the ecological environment; 3. This method combines the surface water-groundwater coupling model and parameters under different hardening conditions, and can be widely used in water resources management, ecological protection and other fields, which helps to more effectively manage and protect water resources and ecosystems. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 It is a flow chart of a method for simulating river channel hardening in a surface water-groundwater coupling model in an embodiment of the present application. Figure 2 It is a sub-step flow chart of S10 in the embodiment of the present application. Figure 3 It is a sub-step flow chart of S20 in the embodiment of the present application. Figure 4 It is a sub-step flow chart of S50 in the embodiment of the present application. DETAILED DESCRIPTION

[0005] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and a regional example. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not used to limit the present invention. An embodiment of the present application discloses a method for simulating river channel hardening in a surface water-groundwater coupling model. The method is improved on the basis of the surface water-groundwater coupling model. By expressing the river channel hardening conditions in a differentiated manner, the hydrological processes under different hardening conditions can be considered, making the model more applicable. The method can more accurately understand and predict the interaction between surface water and groundwater, and help evaluate the impact of groundwater recharge and extraction on surface water and the ecological environment. like Figure 1 As shown, the technical method includes the following steps: S10, construct a basic regional surface water-groundwater coupling model. Among them, Intelliway-SSIM is used here as the surface water-groundwater coupling model. Combination Figure 2 , S10 includes the following 4 sub-steps, S101, simplify the boundaries of the study area and the rivers within the area to a reasonable level. Among them, the simplification of research boundaries and river channels can be carried out by referring to the map. S102, divide the study area into triangular grids of different sizes and divide the river channel into rectangular / trapezoidal grids of different lengths. S103, using dem, soil, stratum, land use, and meteorological data to give different attributes to the triangular mesh. Among them, all the above data can be downloaded from public sources. DEM data can be used to assign grid elevation information, soil, stratum, and land use data can be used to assign grid underlying surface data, and Thiessen polygons can be used to assign meteorological attributes to each triangular grid. S20, differential expression of river channel hardening conditions. Combination Figure 3 As shown, S20 includes the following three sub-steps: S201, based on the on-site investigation of river channel hardening conditions, is divided into four categories: ecological river channel, one-sided river channel, two-sided river channel, and three-sided river channel; S202, add the river material expression parameter, River_matype, to the model. Ecological river, one-sided light, two-sided light, and three-sided light are represented by numbers 0, 1, 2, and 3 respectively; S203, fill 0, 1, 2, and 3 into the model input file to complete the differential expression of river channel hardening. S30 expresses the interaction process between the water flow in the river and the surrounding surface water. The interaction process between the water flow in the river channel and the surrounding surface water. When the water level in the river channel is higher than the sum of the river bank height and the depth of the adjacent surface water, the river channel water overflows the river channel and flows to the adjacent surface. On the contrary, when there is surface water on the adjacent side and it is higher than the river channel water level, the adjacent surface water flows into the river channel. The specific formula is as follows: Relative water level of the river ( )>the sum of river bank height (the height from river bottom to ground surface) and the depth of adjacent surface water ( ): Relative water level of the river ( )<the sum of river bank height and adjacent surface water depth( ): in: is the Verriuli coefficient, which represents the effect of weir geometry and flow conditions; is the effective length of the weir, i.e. the cross-sectional length of the weir through which the water flows, here the length of the river reach; It is the vertical distance between the river water level and the surface water level; n is the flow index. S40, expresses the interaction between the water flow in the river and the surrounding groundwater according to the different types of hardening of the river channel. Among them, the hardened surface does not interact. Ecological river channel (River-matype=0): Each side can interact with groundwater according to the head difference; One-sided light (River-matype=1): Only non-hardened surfaces can interact with groundwater based on the water head difference; Two-sided light (River-matype=2): Only the bottom of the riverbed can interact with groundwater according to the head difference on both sides of the riverbed; Three-sided light (River-matype=3): All three sides cannot interact with the surrounding groundwater; The formula for interaction calculation is as follows: in: is soil moisture; is the soil water flux; is the absolute elevation; K is soil hydraulic conductivity; is the river water level; is the riverbed elevation; is the soil pressure potential; It is the difference between the river water level and the surrounding groundwater level. S50, based on the basic regional surface water-groundwater coupling model, coupling steps two, three and four, realizes the differentiated simulation of the hydrodynamic process of the river under different river hardening categories. Combination Figure 4 As shown, S50 includes the following 7 sub-steps: S501, at T=0, receiving model initialization data; The initialization data are the model parameters set by the user. S502, T=T+1, the time is updated to the next step length. S503, calculating the runoff generation and convergence on land, the interaction between surface runoff and groundwater, the interaction between land grids, and evapotranspiration at time T, and obtaining the surface water level and groundwater level of each triangular grid. The calculation of each process takes the system state quantity of the previous step as the initial condition of the calculation of this step, reads the meteorological data at time T to drive the model to calculate, and calculates the surface water level and groundwater level of each grid. S504, calculating the interaction between the river channel and the surrounding surface water. If the river channel water level is higher than the surface water level, the river channel water flows to the surface, and vice versa, the surface water flows to the river channel. The surface water level of the triangular grid around the river channel and the surface water level inside the river channel are calculated by S503. S505: Calculate the interaction between the river channel and surrounding groundwater according to the river channel material. Among them, the groundwater level of the triangular grid around the river channel, the surface water level and groundwater level inside the river channel are calculated by S503. S506, judging whether T is equal to Tend, where Tend represents the end time of the model simulation, and if T≠Tend, then steps S502-S506 are calculated repeatedly until T=Tend. S507, output the interaction results between the river water and the surrounding surface water and groundwater within the model simulation time. This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A method for simulating river channel hardening in a surface water-groundwater coupling model, characterized in that: The method comprises: Step 1: Construct a basic regional surface water-groundwater coupling model; Step 2: Differentiate and express the hardening of the river channel; Step 3: Express the interaction process between the water flow in the river and the surrounding surface water; Step 4: According to the different types of hardening of the river channel, express the interaction process between the water flow in the river channel and the surrounding groundwater; Step 5: Based on the basic regional surface water-groundwater coupling model, couple steps 2, 3, and 4 to achieve differentiated simulation of river hydrodynamic processes under different river hardening categories.

2. The method according to claim 1, characterized in that The surface water-groundwater coupling model can be a commonly used numerical simulation software with three-dimensional surface water-groundwater coupling simulation function. This claim describes the surface water-groundwater coupling model (inteliway-SSIM) independently developed by Beijing Inteliway as an example.

3. The method according to claim 1, characterized in that The specific contents of constructing the surface water-groundwater coupling model described in step 1 include differentiated expression of rivers of different levels according to the river characteristics of the study area and the research objectives, defining the boundaries of the simulation area based on the river distribution, performing unstructured grid division on the land part in the simulation area, performing structured grid division on the river area, and localizing the parameters of the region according to the regional soil, land use, lithology distribution, etc.

4. The method according to claim 1, characterized in that Step 2 describes the differential expression of the river channel hardening situation, specifically: Through field investigation, the materials of the rivers in the study area are divided into four categories: ecological river (River-matype=0) means that the river is not hardened, one-sided smooth river (River-matype=1) means that one side of the river is made of hard material, two-sided smooth river (River-matype=2) means that both sides of the river are made of hard materials, and three-sided smooth river (River-matype=3) means that both the sides and bottom of the river are made of hard materials.

5. The method according to claim 1, characterized in that As described in step three, the interaction process between the water flow in the river channel and the surrounding surface water is expressed. When the water level in the river channel is higher than the sum of the river bank height and the surface water depth on the side, the river channel water overflows the river channel and flows to the side surface. Conversely, when there is surface water on the side and it is higher than the river channel water level, the side surface water flows into the river channel.

6. The method according to claim 1, characterized in that As described in step 4, the interaction process between the river channel and the surrounding groundwater is expressed according to the hardening of the river channel, where: Ecological river channel (River-matype=0): The water in the river channel can infiltrate into the riverbed and the soil beside it. At the same time, the water in the riverbed and the soil beside it can also infiltrate to replenish the water in the river channel. One-sided light river (River-matype=1): The river water and the surrounding groundwater can interact at non-hard materials, but the river water and the surrounding groundwater cannot interact at hard materials; Two-sided smooth river (River-matype=2): Similarly, only the river flow at the non-hard material can interact with the surrounding groundwater; Three-sided hard river (River-matype=3): Since the three sides are made of hard materials, the river water cannot interact with the groundwater.

7. The method according to claim 1, characterized in that As described in step 5, based on the basic regional surface water-groundwater coupling model, the response of the river hydrodynamic process and its surrounding hydrological process under different river hardening categories is expressed, which includes the following steps: Step 1: At a certain time T, calculate the land runoff generation and convergence process, the interaction process between surface runoff and groundwater, the interaction process between land grids, and the evapotranspiration process, and obtain the surface water level and groundwater level of the unstructured grid in the area around the river; Step 2: At a certain time T, calculate the upstream inflow and downstream outflow process of the river channel to obtain the river water level in the river channel grid; Step 3: When the water level in the river channel is higher than the sum of the river bank and the adjacent surface water heights, the river channel water overflows the adjacent surface, affecting the adjacent surface hydrological process and the surface water-groundwater interaction process; when the water level in the river channel is lower than the river bank and there is adjacent surface water, the adjacent surface water can flow into the river channel; Step 4: Calculate the interactive water volume between the river water and the surrounding groundwater at the non-hard material location, depending on whether the river channel side and bottom are hard materials; Step 5: Complete all the above calculation processes, use the state at time T as the initial condition for the next time T=T+1, and repeat the calculations from step 1 to step 4 until the end of the model simulation.

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