A simulation method for the dynamic interaction between surface water / groundwater around a lake and the water volume in the lake body

Abstract

The present invention discloses a method for simulating the dynamic interaction between surface water / groundwater around a lake and the water volume of the lake body. The method constructs a surface water-groundwater coupling model; characterizes grids with open boundaries around the lake; develops interactive calculations between surface water around the lake and lake water; develops interactive calculations between groundwater around the lake and lake water; receives model data, calculates the amount of interaction between the lake body and the surrounding groundwater / surface water during the simulation time, and outputs the results. The technical effect of this application is that by expressing the open boundaries of the watershed, the interaction process between surface water / groundwater and lake water in the watershed around the lake is developed, which not only improves the hydrological process of the watershed's recharge / discharge to the lake body, but also improves the accuracy of the water volume interaction calculation results.

Description

Technical Field

[0001] The present invention relates to the technical field of dynamic interactive water volume simulation methods, and in particular to a simulation method for the dynamic interaction of surface water / groundwater around a lake and the water volume of a lake body. Background Art

[0002] The quantity and quality of lake water are influenced by the surrounding surface water and groundwater. Understanding the dynamic relationship between these factors contributes to effective water resource management. Managing lake water quantity requires accurate modeling and prediction so that appropriate measures can be taken under varying climatic and environmental conditions.

[0003] Traditional lake hydrological models typically treat lakes as isolated systems, ignoring the impact of surrounding surface and groundwater on lake levels and volume. However, in reality, complex interactions exist between surface and groundwater and lakes, and these relationships can be influenced by geographical conditions, climate change, and human activities. Summary of the Invention

[0004] Purpose of the invention: The present invention proposes a simulation method for the dynamic interaction between surface water / groundwater around a lake and the water volume of the lake body. By integrating the surface water-groundwater coupling model, a surface water-lake water interaction module and a groundwater-lake water interaction module are developed, thereby improving the accuracy of the calculation results.

[0005] Technical solution: The present invention proposes a method for simulating the dynamic interaction between surface water / groundwater around a lake and the water volume of the lake body, which is characterized by comprising the following steps:

[0006] Step 1: Build a surface water-groundwater coupling model and collect absolute water level data of the lake;

[0007] Step 2: Characterize the area where surface water / groundwater around the lake interacts with the lake body. The surface water around the lake includes river water and surface diffuse flow.

[0008] Step 3: Develop an interactive calculation and simulation module for the surface water around the lake and the lake water, which is used to simulate the recharge relationship between the surface water around the lake and the lake water based on the relationship between the water level of the surface water around the lake and the water level of the lake body;

[0009] Step 4: Develop an interactive calculation and simulation module for the groundwater around the lake and the lake water, which is used to simulate the recharge relationship between the groundwater around the lake and the lake water level based on the relationship between the water level of the groundwater around the lake and the water level of the lake body;

[0010] Step 5: Receive absolute water level data, calculate the interaction between the lake and surrounding surface water / groundwater during the simulation time, and output the results.

[0011] Preferably, the surface water-groundwater coupling model in step 1 is numerical simulation software with three-dimensional surface water-groundwater coupling simulation function, specifically Intelliway-SSIM.

[0012] Preferably, the step 1 includes the following steps:

[0013] S101: Simplify river courses and basin boundaries;

[0014] S102: Divide the land area around the lake into a number of triangular grids of varying sizes, and divide the river channel around the lake into a number of rectangular / trapezoidal grids of varying lengths;

[0015] S103: Parameter localization.

[0016] Preferably, the specific steps of step 2 include:

[0017] S201: Identify the land triangle meshes that have water volume interaction with the lake body, and record them as EleID; identify the river meshes that have water volume interaction with the lake body, and record them as RivID;

[0018] S202: assigning RexchangeWithLake to the identified RivID as a river water characterization tag;

[0019] S203: Assign EexchangeWithLake to the identified EleID as a surface flow and groundwater characterization tag.

[0020] Preferably, the surface water interaction calculation formula in step 3 is the Saint-Venant formula:

[0021]

[0022] Where: x is the distance between the marked grid center point and the lake edge; t is the time step of the model calculation; A is the flow area, perpendicular to the direction of water flow; Q is the interaction flow between surface water and lake water; H is the head difference between surface water and lake water; Sf is the friction slope, that is, the head loss per unit distance; g is the acceleration of gravity.

[0023] Preferably, the groundwater interaction calculation formula in step 4 is Darcy's formula:

[0024]

[0025] Where Q is the flow rate per unit time through the perimeter of the lake, between the lake water and the land interface; k is the permeability of the porous medium; A is the cross-sectional area, perpendicular to the flow direction; Δh is the hydraulic head difference of the fluid in the porous medium; L is the distance between the center point of the marked grid and the lake edge.

[0026] Preferably, the step five comprises the following steps:

[0027] S501: At time T=0, initialization data of the surface water-groundwater coupling model is received to form the initial water level conditions of the water level in the river grid and the surface diffuse flow water level;

[0028] S502: Based on the initial conditions of the surface water-groundwater coupling model, the runoff generation and confluence process on land, the interaction process between surface water and groundwater, the interaction process between land grids, the evapotranspiration process, the interaction process between surface water and groundwater between river segments and surrounding grids, the upstream and downstream migration process of river water, and the upstream and downstream migration process of land surface water and groundwater are calculated at time T+1. Finally, the current surface water level and groundwater level of the land triangular grid that interacts with the lake body are obtained, as well as the river water level at the lake entrance.

[0029] S503: Receive lake water level monitoring data and surface water / groundwater levels at time T+1, and calculate the interaction between the surface water and groundwater around the lake and the lake water at time T+1 based on the Darcy formula and the Saint-Venant formula. Obtain the interaction between the surface water around the lake and the lake water, as well as the interaction between the groundwater around the lake and the lake water at time T+1.

[0030] S504: Update time T=T+1, and determine whether T is equal to the simulation end time Tend;

[0031] S505: If T≠Tend, then the watershed state at the current moment is used as the initial condition and S502 to S504 are repeatedly calculated. Otherwise, the model calculation ends and the time series of the interaction amount at each moment is output.

[0032] Beneficial effects: The present invention proposes a simulation method for the dynamic interaction between surface water / groundwater around a lake and the water volume of the lake body, which helps to more accurately understand and predict the interaction between surface water / groundwater and lake water; by using the lake water level as the model boundary, the impact of the lake water level on the hydrological process of surface water / groundwater in the basin is taken into account, making the basin hydrological process more complete and the model more applicable; by accurately calculating the interaction volume between surface water / groundwater and lake water in the basin, the application of water resource management of the lake is improved; this method can be widely used in water resource management, ecological protection and other fields, and helps to more effectively manage and protect water resources and ecosystems. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart of a method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in the lake body according to an embodiment of the present application;

[0034] Figure 2 This is a flowchart of the sub-steps of step one in the embodiment of the present application;

[0035] Figure 3 This is a sub-step flow chart of step 2 in the embodiment of the present application;

[0036] Figure 4 This is a flowchart of the sub-steps of step five in the embodiment of the present application;

[0037] Figure 5 It is the interaction time series between the surface water and the lake water of a certain unit lakeshore in an area in the embodiment of the present application;

[0038] Figure 6 It is the interaction time series between groundwater and lake water in a certain area of the lake shoreline in the embodiment of the present application. DETAILED DESCRIPTION

[0039] The present invention discloses a simulation method for the dynamic interaction between surface water / groundwater around a lake and the water volume of the lake body. The method is improved on the basis of a surface water-groundwater coupling model, and a new interaction calculation simulation module for the surface water / groundwater around the lake and the lake water is developed. The method can accurately calculate the time-space interaction process and interaction volume between the surface water / groundwater around the lake and the lake water. The improvement of this method not only helps to improve the hydrological process between the river basin and the lake body, but also provides strong support for the management of lake water resources, and also helps to accurately calculate terrestrial surface water and groundwater.

[0040] like Figure 1 As shown, the technical method includes the following steps:

[0041] Step 1: Build a surface water-groundwater coupling model and receive lake monitoring water level data as boundary conditions.

[0042] The surface water-groundwater coupling model used here is Intelliway-SSIM.

[0043] Combine Figure 2 , S10 includes the following 3 sub-steps,

[0044] S101, simplify the boundaries of the study area and the rivers within the area to a reasonable level.

[0045] Among them, according to the research purpose, the research boundary and river channel can be simplified by comparing the map in GIS.

[0046] S102, divide the study area into triangular grids of varying sizes, and divide the river channel into rectangular / trapezoidal grids of varying lengths.

[0047] The meshing tool is PIHMgis, and the simplified river network is used as a constraint to generate the triangulated mesh.

[0048] S103, using dem, soil, stratum, land use, and meteorological data to assign different attributes to the triangular mesh.

[0049] Among them, all the above data can be downloaded from public sources. The 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.

[0050] Step 2: Characterize the areas around the lake where there is interaction between terrestrial surface water / groundwater and the lake body.

[0051] Combine Figure 3 As shown, S20 includes the following three sub-steps:

[0052] S201, prepare the lake boundary, triangular mesh, and river channel mesh shape layers;

[0053] S202, identifying the EleID and RivID that are in full contact with the lake boundary in ArcGIS;

[0054] S203: Add characteristic tags EexchangeWithLake and RexchangeWithLake to the marked EleID and RivID.

[0055] S30, develop an interactive calculation and simulation module for the surface water around the lake and the lake water.

[0056] The surface water interaction occurs in the land triangulated grid marked EexchangeWithLake and the river rectangular / trapezoidal grid. The water recharge direction is determined by the absolute water level difference between the surface water and the lake water. If the surface water level is higher than the lake water level, the surface water recharges the river; otherwise, the lake water recharges the surface water. The surface water interaction calculation formula is the Saint-Venant formula:

[0057]

[0058] Where: x is the distance between the marked grid center point and the lake edge; t is the time step of the model calculation; A is the flow area, perpendicular to the direction of water flow; Q is the interaction flow between surface water and lake water; H is the head difference between surface water and lake water; Sf is the friction slope, that is, the head loss per unit distance; g is the acceleration of gravity.

[0059] Step 4: Develop an interactive calculation and simulation module for groundwater and lake water around the lake.

[0060] The groundwater interaction here also occurs in the land triangulation grid marked EexchangeWithLake. The water recharge direction is determined by the absolute water level difference between the groundwater and lake water. When the groundwater level in the grid is higher than the lake level, the groundwater recharges the lake, and vice versa. The groundwater interaction calculation formula is Darcy's formula:

[0061]

[0062] Where Q is the flow rate per unit time through the perimeter of the lake, between the lake water and the land interface; k is the permeability of the porous medium; A is the cross-sectional area, perpendicular to the flow direction; Δh is the hydraulic head difference of the fluid in the porous medium; L is the distance between the center point of the marked grid and the lake edge.

[0063] Step 5: Receive model data, calculate the interaction between the lake and the surface water / groundwater in the surrounding land during the simulation time, and output the results.

[0064] Combine Figure 4 As shown, S50 includes the following 5 sub-steps:

[0065] S501, T=0, receiving model initialization data as the initial state of the model;

[0066] The initialization data are the model parameters set by the user.

[0067] S502, T = T + 1, the time is updated to the next step length; calculate the land runoff, the interaction between surface water and groundwater, the interaction between land grids, evapotranspiration, the interaction between surface water and groundwater between the river section and the surrounding grids, the upstream and downstream migration of river water, and the upstream and downstream migration of land surface water and groundwater, and obtain the surface water and groundwater levels in the area interacting with the lake water.

[0068] The calculation of each process is based on the system state quantity of the previous step as the initial condition for the calculation of this step. The meteorological data at time T is read to drive the surface water-groundwater coupling model to perform calculations, and the surface water level and groundwater level of each grid are calculated.

[0069] S503: Receive lake water level monitoring data at time T and calculate the interaction between the surface water / groundwater around the lake and the lake water.

[0070] Among them, the surface water level and groundwater level of the triangular grid around the lake and the surface water level inside the river channel are calculated by S502.

[0071] S504: Update time T=T+1, and determine whether T is equal to the simulation end time Tend;

[0072] S505: If T≠Tend, then the watershed state at the current moment is used as the initial condition and S502 to S504 are repeatedly calculated. Otherwise, the model calculation ends and the time series of the interaction amount at each moment is output.

[0073] The calculation of the surface water-groundwater coupling model (inteliway-SSIM) of a certain area is taken as an example to illustrate the effectiveness and rationality of the invented method.

[0074] like Figure 5 The figure shows the interaction time series between surface water and lake water per unit lake shoreline length in a certain area from 2018 to 2019. Figure 6 For this area, the time series of the interaction between groundwater and lake water per unit length of lake shoreline is shown between 2018 and 2019. The results of the interaction between surface water and groundwater and lake water are all on an hourly scale.

Claims

1. A method for simulating the dynamic interaction between surface water / groundwater around a lake and the water volume of the lake, characterized in that: The following steps are involved: Step 1: Build a surface water-groundwater coupling model using Intelliway-SSIM and collect absolute water level data of the lake: S101: Simplify river courses and basin boundaries; S102: Divide the land area around the lake into a number of triangular grids of varying sizes, and divide the river channel around the lake into a number of rectangular / trapezoidal grids of varying lengths; S103: parameter localization; Step 2: Characterize the area where surface water / groundwater around the lake interacts with the lake. The surface water around the lake includes river water and surface flow. S201: Identify the land triangle meshes that have water volume interaction with the lake body, and record them as EleID; identify the river meshes that have water volume interaction with the lake body, and record them as RivID; S202: assigning RexchangeWithLake to the identified RivID as a river water characterization tag; S203: assigning EexchangeWithLake to the identified EleID as a surface flow and groundwater characterization tag; Step 3: Develop an interactive calculation simulation module for the surface water around the lake and the lake water, which is used to simulate the recharge relationship between the surface water around the lake and the lake water based on the relationship between the water level of the surface water around the lake and the water level of the lake body: A. When the water level in the river grid marked RexchangeWithLake is higher than the water level in the lake, the river water replenishes the lake, and vice versa; B. When the surface diffuse flow water level in the land triangle grid marked EexchangeWithLake is higher than the lake water level, the surface water flows into the lake; otherwise, the water in the lake overflows the surface. The water level in the river grid, the surface flow water level, and the lake water level are all absolute water levels. The surface water interaction here occurs in the land triangular grid marked EexchangeWithLake and the river rectangular / trapezoidal grid. The absolute water level difference between the surface water and the lake water is used to determine the direction of water recharge. Step 4: Develop an interactive calculation simulation module for the groundwater around the lake and the lake water, which is used to simulate the recharge relationship between the groundwater around the lake and the lake water level based on the relationship between the water level of the groundwater around the lake and the water level of the lake body: Here, groundwater interaction occurs in the land triangulated mesh marked EexchangeWithLake. When the groundwater level in the mesh is higher than the lake level, groundwater replenishes the lake, and vice versa. The groundwater level and lake level in the mesh are both absolute water levels. Here, groundwater interaction also occurs in the land triangulated mesh marked EexchangeWithLake. The direction of water replenishment is determined by the absolute water level difference between groundwater and lake water. Step 5: Receive absolute water level data, calculate the interaction between the lake and surrounding surface water / groundwater during the simulation time, and output the results: S501: At time T=0, initialization data of the surface water-groundwater coupling model is received to form the initial water level conditions of the water level in the river grid and the surface diffuse flow water level; S502: Based on the initial conditions of the surface water-groundwater coupling model, the runoff generation and confluence process on land, the interaction process between surface water and groundwater, the interaction process between land grids, the evapotranspiration process, the interaction process between surface water and groundwater between river segments and surrounding grids, the upstream and downstream migration process of river water, and the upstream and downstream migration process of land surface water and groundwater are calculated at time T+1. Finally, the current surface water level and groundwater level of the land triangular grid that interacts with the lake body are obtained, as well as the river water level at the lake entrance. S503: Receive lake water level monitoring data and surface water / groundwater levels at time T+1, and calculate the interaction between the surface water and groundwater around the lake and the lake water at time T+1 based on the Darcy formula and the Saint-Venant formula. Obtain the interaction between the surface water around the lake and the lake water, as well as the interaction between the groundwater around the lake and the lake water at time T+1. S504: Update time T=T+1, and determine whether T is equal to the simulation end time Tend; S505: If T≠Tend, then the watershed state at the current moment is used as the initial condition and S502 to S504 are repeatedly calculated. Otherwise, the model calculation ends and the time series of the interaction amount at each moment is output.

2. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in the lake according to claim 1, characterized in that: The surface water interaction calculation formula in step 3 is the Saint-Venant formula: Where: x is the distance between the marked grid center point and the lake edge; t is the time step of the model calculation; A is the flow area, perpendicular to the direction of water flow; Q is the interaction flow between surface water and lake water; H is the head difference between surface water and lake water; Sf is the friction slope, that is, the head loss per unit distance; g is the acceleration of gravity.

3. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in the lake according to claim 1, characterized in that: The groundwater interaction calculation formula in step 4 is Darcy's formula: Where Q is the flow rate per unit time through the perimeter of the lake, between the lake water and the land interface; k is the permeability of the porous medium; A is the cross-sectional area, perpendicular to the flow direction; Δh is the hydraulic head difference of the fluid in the porous medium; L is the distance between the center point of the marked grid and the lake edge.

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