Simulation method for dynamic interaction of lake-surrounding surface water / underground water and lake water volume

Abstract

The invention discloses a method for simulating dynamic interaction of lake-surrounding surface water / underground water and lake water volume. The method comprises the following steps: constructing a surface water-underground water coupling model; carrying out characterization expression on grids with open boundaries around the lake; interactive calculation of surface water around the lake and lake water is developed; interactive calculation of groundwater around the lake and lake water is developed; and receiving model data, calculating the interaction amount of the lake body and surrounding underground water / surface water in the simulation time, and outputting a result. The method has the technical effects that the interaction process of surface water / underground water and lake water of the basin surrounding the lake is developed by expressing the open boundary of the basin, the hydrological process of supply / discharge of the basin to the lake body is perfected, and the accuracy of a water volume interaction calculation result is also improved.

Description

Technical Field

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

[0002] The water quantity and quality of lakes are affected by the surrounding surface water and groundwater, and understanding the dynamic relationship between them helps to effectively manage water resources. The management of lake water quantity requires accurate simulation and prediction so that appropriate measures can be taken under different climatic and environmental conditions.

[0003] Traditional lake hydrological models usually treat lakes as isolated systems, ignoring the impact of surrounding surface water and groundwater on lake water levels and volumes. However, in reality, there are complex interactions between surface water and groundwater and lakes, which may be affected 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 the surface water / groundwater around the lake and the water volume in the lake body. Through the integrated development of the surface water-groundwater coupling model, a surface water-lake water interaction module and a groundwater-lake water interaction module are developed to improve 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: Step 1: Build a surface water-groundwater coupling model and collect absolute water level data of the lake; Step 2: Characterize the area where the surface water / groundwater around the lake interacts with the lake body. The surface water around the lake includes river water and surface diffuse flow. 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; Step 4: Develop an interactive calculation simulation module for groundwater around the lake and lake water, which is used to simulate the recharge relationship between groundwater around the lake and lake water based on the relationship between the water level of the groundwater around the lake and the water level of the lake body; 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.

[0006] Preferably, the surface water-groundwater coupling model in step 1 is a numerical simulation software with a three-dimensional surface water-groundwater coupling simulation function, specifically, Inteliway-SSIM.

[0007] Preferably, the step 1 comprises the following steps: S101: Simplify river courses and basin boundaries; S102: Divide the land area around the lake into a number of triangular grids of different sizes, and divide the river channel around the lake into a number of rectangular / trapezoidal grids of different lengths; S103: Parameter localization.

[0008] Preferably, the specific steps of step 2 include: S201: Identify the land triangular 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: Assign EexchangeWithLake to the identified EleID as a surface flow and groundwater characterization tag.

[0009] Preferably, the surface water interaction calculation formula in step 3 is Saint-Venant's formula: (1.1) (1.2) 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 water flow direction; 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.

[0010] Preferably, the groundwater interaction calculation formula in step 4 is Darcy's formula: (2.1) Among them, Q is the flow rate through the perimeter of the lake, between the lake water and the land in unit time; 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, and L is the distance between the marked grid center point and the lake edge.

[0011] Preferably, the step five comprises the following steps: 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: Calculate 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 in the river section and the surrounding grids, the upstream and downstream migration process of river water, and the upstream and downstream migration process of land surface water and groundwater at time T+1 according to the initial conditions of the surface water-groundwater coupling model. Finally, the current surface water level and groundwater level of the land triangular grid that interacts with the lake body and the river water level at the lake entrance are obtained. S503: receiving the lake water level monitoring data and the surface water / groundwater level at time T+1, and calculating the interaction between the surface water and groundwater around the lake and the lake water at time T+1 according to the Darcy formula and the Saint-Venant formula; obtaining the interaction amount between the surface water around the lake and the lake water and the interaction amount 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 calculated repeatedly. Otherwise, the model calculation ends and the time series of the interaction amount at each moment is output.

[0012] Beneficial effects: The simulation method of the dynamic interaction between surface water / groundwater around a lake and the water volume of the lake body proposed in the present invention 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 influence 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 amount between surface water / groundwater and lake water in the basin, the application of water resources management of the lake is improved; the method can be widely used in water resources management, ecological protection and other fields, and helps to more effectively manage and protect water resources and ecosystems. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a flow chart of a simulation method for dynamic interaction between surface water / groundwater around a lake and water volume in a lake body in an embodiment of the present application; Figure 2 is a sub-step flow chart of step one in an embodiment of the present application; Figure 3 It is a sub-step flow chart of step 2 in the embodiment of the present application; Figure 4 is a sub-step flow chart of step five in the embodiment of the present application; Figure 5 is the interaction time series between the surface water and the lake water of the lake shoreline of a certain area in the embodiment of the present application; 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

[0014] The present invention discloses a simulation method for the dynamic interaction between surface water / groundwater around a lake and the water volume of a lake body. The method is improved on the basis of a surface water-groundwater coupling model, and a new interaction calculation simulation module for surface water / groundwater around a lake and lake water is developed, which can accurately calculate the interaction process and interaction volume between surface water / groundwater around a lake and lake water in time and space. The improvement of this method not only helps to improve the hydrological process between the watershed 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.

[0015] like Figure 1 As shown, the technical method includes the following steps: Step 1: Construct a surface water-groundwater coupling model and receive lake monitoring water level data as boundary conditions.

[0016] Among them, the surface water-groundwater coupling model used here is Inteliway-SSIM.

[0017] Combination Figure 2 , S10 includes the following three sub-steps, S101, simplify the boundaries of the study area and the rivers within the area to a reasonable level.

[0018] Among them, the study boundary and river channel can be simplified by comparing the map in GIS according to the research purpose.

[0019] S102, divide the study area into triangular grids of different sizes and divide the river channel into rectangular / trapezoidal grids of different lengths.

[0020] The meshing tool is PIHMgis, and the simplified river network is used as a constraint to generate triangular meshes.

[0021] S103, using dem, soil, stratum, land use, and meteorological data to give different attributes to the triangular mesh.

[0022] 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.

[0023] Step 2: Characterize the areas around the lake where there is interaction between terrestrial surface water / groundwater and the lake body.

[0024] Combination Figure 3 As shown, S20 includes the following three sub-steps: S201, prepare lake boundary, triangular mesh, and river channel mesh shape layers; S202, EleIDs and RivIDs that are completely in contact with the lake boundary were identified in ArcGIS; S203, adding characteristic tags EexchangeWithLake and RexchangeWithLake to the marked EleID and RivID.

[0025] S30, develop an interactive calculation and simulation module for the surface water around the lake and the lake water.

[0026] The groundwater interaction here occurs in the land triangular grid marked EexchangeWithLake and the river rectangular / trapezoidal grid. The water recharge direction is determined by the absolute water level difference between surface water and lake water. If the surface water level is higher than the lake water level, the surface water recharges the river, and vice versa, the lake water recharges the surface water. The surface water interaction calculation formula is the Saint-Venant formula: (1.1) (1.2) 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 water flow direction; 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.

[0027] Step 4: Develop an interactive calculation and simulation module for groundwater and lake water around the lake.

[0028] The groundwater interaction here also occurs in the land triangular grid marked EexchangeWithLake. When the groundwater level in the grid is higher than the lake level, the groundwater replenishes the lake, and vice versa. The groundwater interaction calculation formula is Darcy's formula: (2.1) Among them, Q is the flow rate through the perimeter of the lake, between the lake water and the land in unit time; 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, and L is the distance between the marked grid center point and the lake edge.

[0029] 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.

[0030] Combination Figure 4 As shown, S50 includes the following 5 sub-steps: S501, T=0, receiving model initialization data as the initial state of the model; The initialization data are the model parameters set by the user.

[0031] S502, T=T+1, the time is updated to the next step length; calculate the runoff on land, the interaction between surface water and groundwater, the interaction between land grids, evapotranspiration, the interaction between surface water and groundwater in the river section and the surrounding grids, the upstream and downstream migration of river water, and the upstream and downstream migration process of land surface water-groundwater, and obtain the surface water and groundwater levels in the interaction area with the lake water.

[0032] The calculation of each process is based on the system state quantity of the previous step as the initial condition of the calculation of this step. The meteorological data at time T is read to drive the surface water-groundwater coupling model to calculate the surface water level and groundwater level of each grid.

[0033] S503, receiving lake water level monitoring data at time T, and calculating the interaction between the surface water / groundwater around the lake and the lake water.

[0034] Among them, the surface water level and groundwater level of the triangular grid around the lake and the surface water level inside the river are calculated by S502.

[0035] 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 calculated repeatedly. Otherwise, the model calculation ends and the time series of the interaction amount at each moment is output.

[0036] 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.

[0037] like Figure 5 As shown, it is the interaction time series between surface water and lake water per unit lakeshore length in a certain area from 2018 to 2019; Figure 6 For this area, the interaction time series between groundwater and lake water per unit length of lake shoreline in 2018 and 2019. The interaction results 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 water volume in the lake, characterized in that: The following steps are involved: Step 1: Build a surface water-groundwater coupling model and collect absolute water level data of the lake; Step 2: Characterize the area where the surface water / groundwater around the lake interacts with the lake body. The surface water around the lake includes river water and surface diffuse flow. 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; Step 4: Develop an interactive calculation simulation module for groundwater around the lake and lake water, which is used to simulate the recharge relationship between groundwater around the lake and lake water based on the relationship between the water level of the groundwater around the lake and the water level of the lake body; 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.

2. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in a lake according to claim 1, characterized in that: The surface water-groundwater coupling model in step 1 is a numerical simulation software with three-dimensional surface water-groundwater coupling simulation function, specifically Inteliway-SSIM.

3. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in a lake according to claim 1 or 2, characterized in that: The step 1 comprises the following steps: S101: Simplify river courses and basin boundaries; S102: Divide the land area around the lake into a number of triangular grids of different sizes, and divide the river channel around the lake into a number of rectangular / trapezoidal grids of different lengths; S103: Parameter localization.

4. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in a lake according to claim 3, characterized in that: The specific steps of step 2 include: S201: Identify the land triangular 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: Assign EexchangeWithLake to the identified EleID as a surface flow and groundwater characterization tag.

5. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in a lake according to claim 4, characterized in that: The specific steps of step three are: A. When the water level of the river in the river grid marked RexchangeWithLake is higher than the water level of the lake, the water from the river replenishes the lake, and vice versa; B. When the surface diffuse flow water level in the land triangle grid marked with 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.

6. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in a lake according to claim 5, characterized in that: In the step 4, the interactive calculation simulation module of the groundwater around the lake and the lake water, the groundwater interaction here occurs in the terrestrial triangular grid marked EexchangeWithLake. When the groundwater level in the grid is higher than the lake water level, the groundwater replenishes the lake, and vice versa, the water in the lake replenishes the groundwater. The groundwater level in the grid and the lake water level are both absolute water levels.

7. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in a lake according to claim 6, characterized in that: The surface water interaction calculation formula in step 3 is the Saint-Venant formula: （1.1）； （1.2）； 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 water flow direction; 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.

8. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in a lake according to claim 7, characterized in that: The groundwater interaction calculation formula in step 4 is Darcy's formula: （2.1）； Among them, Q is the flow rate through the perimeter of the lake, between the lake water and the land in unit time; 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, and L is the distance between the marked grid center point and the lake edge.

9. The method for simulating the dynamic interaction between surface water / groundwater around a lake and water volume in a lake according to claim 8, characterized in that: The step five comprises the following steps: 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: Calculate 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 in the river section and the surrounding grids, the upstream and downstream migration process of river water, and the upstream and downstream migration process of land surface water and groundwater at time T+1 according to the initial conditions of the surface water-groundwater coupling model. Finally, the current surface water level and groundwater level of the land triangular grid that interacts with the lake body and the river water level at the lake entrance are obtained. S503: receiving the lake water level monitoring data and the surface water / groundwater level at time T+1, and calculating the interaction between the surface water and groundwater around the lake and the lake water at time T+1 according to the Darcy formula and the Saint-Venant formula; obtaining the interaction amount between the surface water around the lake and the lake water and the interaction amount 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 calculated repeatedly. Otherwise, the model calculation ends and the time series of the interaction amount at each moment is output.

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