Method and related device for calculating flood inundation range based on grid water level

Abstract

The present application discloses a method for calculating flood inundation range based on grid water level and related devices, and relates to the technical field of flood process prediction. The method comprises: firstly, using a distributed hydrological model to calculate the flow process of each key section of the river channel, and calculating the water level of each key section of the river channel according to the water level-flow relationship, so as to determine the water level of each grid of the river channel, and then by comparing the elevation of the river channel grid with the elevation of other grids in the basin, it can be determined whether each basin grid is inundated, and the flood inundation range is obtained. Compared with the traditional technology of using the finite element method to solve the NS equation and obtain the water depth of each position in the basin, the present application significantly improves the prediction efficiency of the flood inundation range, and provides a basis and support for quickly simulating the flood inundation range, evaluating the impact of flood disasters, and formulating flood control measures in advance.

Description

Technical Field

[0001] The present application relates to the technical field of flood process prediction, and particularly to a method for calculating flood inundation range based on grid water levels and related devices. Background Art

[0002] A flood refers to a natural phenomenon in which the river water level rises rapidly due to reasons such as heavy rain or snowmelt, the water volume exceeds the capacity of the river channel, and then the river water overflows, inundating both banks and low-lying areas. Since ancient times, floods have had a wide impact on human society and the environment. Especially in densely populated and economically developed areas, floods not only cause significant economic losses but also pose a serious threat to human lives and infrastructure.

[0003] To effectively prevent and mitigate the impact of flood disasters, flood inundation range simulation technology has emerged. By simulating the flood inundation range, the affected areas of floods can be predicted, flood control measures can be formulated in advance, land use planning can be optimized, and disaster losses can be reduced. Currently, the main method for calculating the flood inundation range is the hydrodynamic model. The hydrodynamic model is based on the equations of mass conservation and momentum conservation, divides the basin into multiple grid areas, and uses the finite element method to solve the NS equations to obtain the water depths at various positions in the basin. Although the calculation results of this method have high accuracy, when dealing with large-scale basins, the modeling difficulty is large and the calculation efficiency is very low, making it difficult to quickly respond to sudden flood events. Summary of the Invention

[0004] The purpose of the present application is to provide a method for calculating flood inundation range based on grid water levels and related devices, which can quickly simulate the flood inundation range and improve the prediction efficiency of the flood inundation range.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] In the first aspect, the present application provides a method for calculating flood inundation range based on grid water levels, including the following steps:

[0007] Obtain the river channel position line, the positions of key river channel sections, basin grid data, basin precipitation data, and the water level - discharge relationship of the key river channel sections; the basin grid data includes topographic grid data, soil grid data, and vegetation grid data.

[0008] Divide the basin into sub-basins according to the positions of the key river channel sections and the topographic grid data, and establish a distributed hydrological model for the basin.

[0009] Based on the basin grid data and the basin precipitation data, use the distributed hydrological model of the basin to simulate the flow process and determine the flow process at the positions of the key river channel sections.

[0010] Determine the water level process at the key river cross-section locations based on the flow process at the key river cross-section locations and the water level - flow relationship of the key river cross-sections.

[0011] Based on the river position line and the basin grid data, determine the river grids in the basin grid, and determine the water level process of each river grid according to the water level process at the key river cross-section locations.

[0012] Based on the water level processes of each river grid and the elevations of each basin grid, determine whether each basin grid is flooded to determine the flood inundation range; early warnings can be issued for villages and towns within the flood inundation range in the basin.

[0013] Optionally, determine the water level process of each river grid according to the water level process at the key river cross-section locations. Specifically: According to the water level processes at two adjacent key river cross-section locations, use the spatial linear interpolation method for interpolation to determine the water level process of each river grid between two adjacent key river cross-section locations.

[0014] Optionally, to determine whether each basin grid is flooded based on the water level processes of each river grid and the elevations of each basin grid, it specifically includes the following steps:

[0015] For each basin grid, determine the river grid closest to the basin grid among the river grids, and assign the water level process of the river grid to the basin grid.

[0016] Based on the water level process of the basin grid and the elevation of the basin grid, determine the water depth process of the basin grid. When the water depth of the basin grid is greater than 0, determine the basin grid as a potentially flooded grid.

[0017] For each potentially flooded grid, determine whether it is connected to each river grid to obtain a connection judgment result.

[0018] If the connection judgment result is yes, determine the potentially flooded grid as a flooded grid.

[0019] If the connection judgment result is no, determine the potentially flooded grid as a non-flooded grid.

[0020] Optionally, the resolution of the terrain grid data should be better than 30m, and it can accurately reflect the terrain of the river positions and the main potential inundation areas within the basin.

[0021] Optionally, the distributed hydrological model of the basin adopts the VIC model.

[0022] Optionally, divide the basin into sub-basins according to the key river cross-section locations and the terrain grid data, which specifically includes the following steps:

[0023] Based on the terrain grid data, divide the basin into catchment areas.

[0024] Sub - basins are delineated for the basin according to the positions of key river cross - sections and the catchment areas within the basin.

[0025] In a second aspect, the present application provides a system for calculating flood inundation extent based on grid water levels, including the following modules:

[0026] A data acquisition module, configured to acquire the river position line, the positions of key river cross - sections, basin grid data, basin precipitation data, and the water level - discharge relationship of key river cross - sections; the basin grid data includes topographic grid data, soil grid data, and vegetation grid data.

[0027] A flow process simulation module, configured to delineate sub - basins for the basin according to the positions of key river cross - sections and topographic grid data, and establish a distributed hydrological model for the basin; according to the basin grid data and basin precipitation data, use the distributed hydrological model for the basin to simulate the flow process and determine the flow process at the positions of key river cross - sections.

[0028] A water level process determination module, configured to determine the water level process at the positions of key river cross - sections according to the flow process at the positions of key river cross - sections and the water level - discharge relationship of key river cross - sections; determine the river channel grids in the basin grid according to the river position line and basin grid data, and determine the water level process of each river channel grid according to the water level process at the positions of key river cross - sections.

[0029] A flood inundation extent determination module, configured to judge whether each basin grid is inundated according to the water level processes of each river channel grid and the elevations of each basin grid, and determine the flood inundation extent; early warnings can be issued for villages and towns within the basin in the flood inundation extent.

[0030] In a third aspect, the present application provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the computer program to implement the steps of the method for calculating flood inundation extent based on grid water levels described above.

[0031] In a fourth aspect, the present application provides a computer - readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method for calculating flood inundation extent based on grid water levels described above are implemented.

[0032] In a fifth aspect, the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, the steps of the method for calculating flood inundation extent based on grid water levels described above are implemented.

[0033] According to the specific embodiments provided by the present application, the following technical effects are disclosed:

[0034] The present application provides a method and related device for calculating the flood inundation range based on grid water levels. In this method, the basin is divided into sub-basins, a distributed hydrological model of the basin is established, and based on the basin grid data and basin precipitation data, the distributed hydrological model of the basin is used to simulate the flow process, determine the flow process at the key cross-section positions of the river channel, then determine the water level process at the key cross-section positions of the river channel according to the water level-flow relationship at the key cross-section positions of the river channel, and further determine the water level process of each river channel grid according to the water level process at the key cross-section positions of the river channel. Finally, according to the water level processes of each river channel grid and the elevations of each basin grid, it is judged whether each basin grid is inundated to determine the flood inundation range, and thus early warnings can be issued for villages and towns within the flood inundation range in the basin. The above solution provided by the present application first calculates the flow processes of each key cross-section of the river channel by using the distributed hydrological model, calculates the water levels of each key cross-section of the river channel according to the water level-flow relationship, and then can determine the water levels of each grid of the river channel. By comparing the elevations of the river channel grids with those of other grids in the basin, it can be determined whether each basin grid is inundated to obtain the flood inundation range. Compared with the traditional technology of solving the NS equation by using the finite element method to obtain the water depths at various positions in the basin, the present application significantly improves the prediction efficiency of the flood inundation range, providing a basis and support for quickly simulating the flood inundation range, evaluating the impact of flood disasters, and formulating flood prevention measures in advance. Brief Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a flowchart of a method for calculating the flood inundation range based on grid water levels provided by an embodiment of the present application.

[0037] Figure 2 It is a schematic diagram of sub-basin division and key cross-sections of the river channel in a method for calculating the flood inundation range based on grid water levels provided by an embodiment of the present application.

[0038] Figure 3 It is a schematic diagram of determining the water levels of river channel grids by performing spatial linear interpolation in a method for calculating the flood inundation range based on grid water levels provided by an embodiment of the present application.

[0039] Figure 4 It is a flowchart of step A6 in a method for calculating the flood inundation range based on grid water levels provided by an embodiment of the present application.

[0040] Figure 5Schematic diagram for determining whether there is connectivity between potentially flooded grids and each river channel grid in a method for calculating flood inundation range based on grid water levels provided by an embodiment of the present application.

[0041] Figure 6 Schematic diagram of the functional modules of a flood inundation range calculation system based on grid water levels provided by an embodiment of the present application.

[0042] Figure 7 Schematic diagram of the structure of a computer device provided by an embodiment of the present application. Detailed implementation manners

[0043] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0044] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0045] In an exemplary embodiment, as Figure 1 shown, a method for calculating flood inundation range based on grid water levels is provided, including the following steps:

[0046] A1. Obtain the river channel position line, the positions of key river channel cross-sections, basin grid data, basin precipitation data, and the water level - discharge relationship of the key river channel cross-sections; the basin grid data includes topographic grid data, soil grid data, and vegetation grid data.

[0047] As an exemplary embodiment, the resolution of the topographic grid data should be better than 30m, which can accurately reflect the terrain of the river channels and the main potential inundation areas within the basin. Specifically in this embodiment, the resolution of the topographic grid data is 12.5m; for the soil grid data, the China soil dataset of the World Soil Database is used, and for the vegetation grid data, the global 1km land cover data of the University of Maryland is used. The precipitation data uses the precipitation process designed for a once-in-a-century event in this basin, and the precipitation duration is 24 hours.

[0048] A2. Divide the basin into sub-basins according to the positions of the key river channel cross-sections and the topographic grid data, and establish a distributed hydrological model for the basin. The outlets of the sub-basins are located at river confluences or key cross-sections, as Figure 2 shown.

[0049] A3. Based on the basin grid data and basin precipitation data, use the distributed hydrological model of the basin to simulate the flow process and determine the flow process at the key cross-section positions of the river channel. In this embodiment, the simulation duration of the distributed hydrological model is 24 hours, and the time step is 1 hour. The flow process refers to the flow values passing through the key cross-section positions of the river channel changing with time.

[0050] A4. Based on the flow process at the key cross-section positions of the river channel and the water level-flow relationship of the key cross-sections of the river channel, determine the water level process at the key cross-section positions of the river channel. The water level process refers to the water level values at the key cross-section positions of the river channel changing with time.

[0051] A5. Based on the river channel position line and the basin grid data, determine the river channel grids in the basin grid, and based on the water level process at the key cross-section positions of the river channel, determine the water level process of each river channel grid, as Figure 3 shown, to obtain the water level process of each river channel grid. In one embodiment, the river channel grid means that the grid value at the position where the river channel line passes is 1, and the grid values in other areas are 0. The position and size of the river channel grid are consistent with those of the terrain grid.

[0052] A6. Based on the water level process of each river channel grid and the elevation of each basin grid, determine whether each basin grid is flooded to determine the flood inundation range; early warnings can be issued for villages and towns within the flood inundation range in the basin.

[0053] In another exemplary embodiment of the present application, in step A5, based on the water level process at the key cross-section positions of the river channel, determining the water level process of each river channel grid specifically includes: based on the water level processes at two adjacent key cross-section positions of the river channel, using the spatial linear interpolation method for interpolation to determine the water level process of each river channel grid between two adjacent key cross-section positions of the river channel.

[0054] In another exemplary embodiment of the present application, as Figure 4 shown in the flowchart, step A6 determines whether each basin grid is flooded based on the water level process of each river channel grid and the elevation of each basin grid, and specifically includes the following steps:

[0055] A61. For each basin grid, determine the river channel grid closest to the basin grid among the river channel grids, and assign the water level process of the river channel grid to the basin grid.

[0056] A62. Based on the water level process of the basin grid and the elevation of the basin grid, determine the water depth process of the basin grid. When the water depth of the basin grid is greater than 0, determine the basin grid as a potentially flooded grid. That is, subtract the elevation of the basin grid from the water level of the basin grid to obtain the water depth of the basin grid. If the water depth is less than 0, it indicates that the basin grid is not flooded; if the water depth is greater than 0, it indicates that the basin grid may be flooded.

[0057] A63. For each potentially flooded grid, determine whether it can be connected to each river channel grid to obtain a connectivity determination result. If the connectivity determination result is yes, execute step A64; if the connectivity determination result is no, execute step A65.

[0058] A64. Determine the potentially flooded grid as a flooded grid.

[0059] A65. Determine the potentially flooded grid as a non-flooded grid. The lack of connectivity between the potentially flooded grid and each river channel grid means that there is at least one non-flooded grid between the potentially flooded grid and the river channel grid, completely disconnecting the potentially flooded grid from the river channel grid, hindering the flow of river water to the potentially flooded area and causing the potentially flooded grid to actually have no water, as Figure 5 shown.

[0060] Based on the above judgment, determine whether each watershed grid is flooded.

[0061] In another exemplary embodiment of the present application, the watershed distributed hydrological model adopts the VIC (Variable Infiltration Capacity) model.

[0062] In another exemplary embodiment of the present application, the watershed is divided into sub-watersheds according to the key cross-section positions of the river channels and the topographic grid data, which specifically includes the following steps:

[0063] According to the topographic grid data, divide the watershed into catchment areas.

[0064] According to the key cross-section positions of the river channels and the catchment areas within the watershed, divide the watershed into sub-watersheds.

[0065] The above solution provided in this embodiment first uses a distributed hydrological model to calculate the flow processes of each key cross-section of the river channels, calculates the water levels of each key cross-section of the river channels according to the water level-flow relationship, and then can determine the water levels of each grid of the river channels. By comparing the elevations of the river channel grids with those of other grids within the watershed, it is possible to determine whether each watershed grid is flooded and obtain the flood inundation range. Compared with the traditional technology of using the finite element method to solve the NS equation to obtain the water depths at various positions within the watershed, the solution of this embodiment significantly improves the prediction efficiency of the flood inundation range, providing a basis and support for quickly simulating the flood inundation range, evaluating the impact of flood disasters, and formulating flood prevention measures in advance.

[0066] The present application also provides an application scenario, which applies the above-mentioned method for calculating the flood inundation range based on grid water levels. Specifically: The method for calculating the flood inundation range based on grid water levels provided in this embodiment can be applied in the flood prevention and disaster reduction scenario. The flood prevention and disaster reduction scenario includes a data collection link, a flood inundation range simulation link, and a disaster prevention warning link; the data within the basin enters the flood inundation range simulation link from the data collection link, and through the method of simulation based on a distributed hydrological model and grid water level calculation, the corresponding flood inundation range is obtained and enters the downstream disaster prevention warning link. The method for calculating the flood inundation range based on grid water levels provided in this embodiment belongs to calculating the grid water level by simulating the flow rate according to the grid data and precipitation data within the basin, and determining the flood inundation range.

[0067] Based on the same inventive concept, the embodiment of the present application also provides a system for calculating the flood inundation range based on grid water levels for implementing the above-mentioned method. The implementation solutions provided by this system for solving problems are similar to the implementation solutions described in the above method. Therefore, the specific limitations in one or more system embodiments provided below can refer to the limitations on the method for calculating the flood inundation range based on grid water levels in the above text, and will not be repeated here.

[0068] In an exemplary embodiment, as Figure 6 shown, a system for calculating the flood inundation range based on grid water levels is provided, including the following modules:

[0069] A data acquisition module, configured to acquire the river channel position line, the positions of key river channel cross-sections, basin grid data, basin precipitation data, and the water level-discharge relationship of key river channel cross-sections; the basin grid data includes topographic grid data, soil grid data, and vegetation grid data.

[0070] A flow process simulation module, configured to divide the basin into sub-basins according to the positions of key river channel cross-sections and topographic grid data, and establish a distributed hydrological model for the basin; according to the basin grid data and basin precipitation data, use the distributed hydrological model for the basin to simulate the flow process and determine the flow process at the positions of key river channel cross-sections.

[0071] A water level process determination module, configured to determine the water level process at the positions of key river channel cross-sections according to the flow process at the positions of key river channel cross-sections and the water level-discharge relationship of key river channel cross-sections; determine the river channel grids in the basin grid according to the river channel position line and basin grid data, and determine the water level process of each river channel grid according to the water level process at the positions of key river channel cross-sections.

[0072] A flood inundation range determination module, configured to determine whether each basin grid is inundated according to the water level processes of each river channel grid and the elevations of each basin grid, and determine the flood inundation range; early warnings can be issued for villages and towns within the basin in the flood inundation range.

[0073] Of course, Figure 6 the architecture shown is only exemplary. When implementing different functions, one or at least two components in the Figure 6 shown system can be omitted according to actual needs.

[0074] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal, and its internal structure diagram can be as Figure 7 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements the method for calculating the flood inundation range based on grid water levels described above.

[0075] Those skilled in the art can understand that Figure 7 the structure shown in

[0076] is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have a different component layout.

[0077] In an exemplary embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented.

[0077] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0078] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0079] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0080] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0081] The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., without limitation.

[0082] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0083] In this text, specific examples are used to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. At the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. To sum up, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A method for calculating flood inundation range based on grid water level, characterized in that: include: Obtaining a river channel position line, a key section position of a river channel, watershed raster data, watershed precipitation data, and a water level-flow relationship of a key section of a river channel; the watershed raster data includes terrain raster data, soil raster data, and vegetation raster data; Divide the watershed into sub-basins according to the key section positions of the river channel and the terrain grid data, and establish a distributed hydrological model of the watershed; According to the watershed raster data and the watershed precipitation data, the flow process is simulated using the watershed distributed hydrological model to determine the flow process at the key section of the river; Determine the water level process at the key section of the river channel according to the flow process at the key section of the river channel and the water level-flow relationship at the key section of the river channel; Determine a river grid in the watershed grid according to the river position line and the watershed grid data, and determine the water level process of each river grid according to the water level process at the key section position of the river; According to the water level process of each river grid and the elevation of each basin grid, it is judged whether each basin grid is flooded and the flood inundation range is determined; early warning can be issued to villages and towns within the flood inundation range in the basin.

2. The method for calculating flood inundation range based on grid water level according to claim 1, characterized in that: According to the water level process at the key section position of the river channel, the water level process of each river channel grid is determined, specifically: according to the water level process at the key section positions of two adjacent river channels, the spatial linear interpolation method is used for interpolation to determine the water level process of each river channel grid between the two adjacent key section positions of the river channel.

3. The method for calculating flood inundation range based on grid water level according to claim 1, characterized in that: According to the water level process of each river grid and the elevation of each basin grid, it is judged whether each basin grid is flooded, including: For each watershed grid, determine the river channel grid closest to the watershed grid in each river channel grid, and assign the water level process of the river channel grid to the watershed grid; Determine the water depth process of the watershed grid according to the water level process of the watershed grid and the elevation of the watershed grid, and determine the watershed grid as a grid that may be submerged when the water depth of the watershed grid is greater than 0; For each possible flooding grid, determine whether the possible flooding grid and each river grid are connected, and obtain a connection determination result; If the connectivity determination result is yes, determining the possible submerged grid as a submerged grid; If the connectivity determination result is negative, the possible submerged grid is determined as a non-submerged grid.

4. The method for calculating flood inundation range based on grid water level according to claim 1, characterized in that: The resolution of the terrain raster data is better than 30m, which can accurately reflect the location of the river channel in the basin and the terrain conditions of the main potential flooding areas.

5. The method for calculating flood inundation range based on grid water level according to claim 1, characterized in that: The basin distributed hydrological model adopts the VIC model.

6. The method for calculating flood inundation range based on grid water level according to claim 1, characterized in that: Dividing the watershed into sub-watersheds according to the key section positions of the river channel and the terrain grid data specifically includes: Dividing the watershed into catchment areas according to the terrain grid data; The basin is divided into sub-basins according to the locations of key sections of the river and the catchment areas within the basin.

7. A flood inundation range calculation system based on grid water level, characterized in that: include: A data acquisition module, used to acquire the river channel position line, the river channel key section position, the watershed raster data, the watershed precipitation data and the water level-flow relationship of the river channel key section; the watershed raster data includes terrain raster data, soil raster data and vegetation raster data; A flow process simulation module is used to divide the watershed into sub-basins according to the key section position of the river channel and the terrain grid data, and establish a distributed hydrological model of the watershed; according to the watershed grid data and the watershed precipitation data, the watershed distributed hydrological model is used to simulate the flow process and determine the flow process at the key section position of the river channel; A water level process determination module is used to determine the water level process at the key section of the river channel according to the flow process at the key section of the river channel and the water level-flow relationship at the key section of the river channel; determine the river channel grid in the watershed grid according to the river channel position line and the watershed grid data, and determine the water level process of each river channel grid according to the water level process at the key section of the river channel; The flood inundation range determination module is used to determine whether each river basin grid is inundated and determine the flood inundation range based on the water level process of each river channel grid and the elevation of each river basin grid; it can issue early warnings to villages and towns within the flood inundation range in the river basin.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the flood inundation range calculation method based on grid water level according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for calculating flood inundation range based on grid water level described in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for calculating flood inundation range based on grid water level described in any one of claims 1 to 6 is implemented.

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