A fast calculation method and system for submerged water depth based on multi-layer grid overlay analysis

Abstract

The present invention discloses a method and system for quickly calculating flood depth based on multi-layer grid overlay analysis, and belongs to the technical field of flood risk analysis. The method includes constructing a meteorological grid, a catchment area grid, and a hydrodynamic model grid; using the intersection area between the meteorological grid and the catchment area grid as the allocation weight, and obtaining real-time rainfall data to calculate the rainfall allocated on the catchment area unit; using the overlay relationship between the catchment area grid and the hydrodynamic model grid and the rainfall allocated on the catchment area unit, the maximum flood depth of the hydrodynamic model grid unit is calculated. The present invention combines distributed databases and parallel computing technology, and proposes an interpolation method based on static-dynamic variable decoupling, which provides results that are relatively consistent with professional models in a short time; through the organic combination of overlay analysis, distributed databases, and parallel computing, not only the accurate calculation of complex data analysis and simulation is achieved, but also the ability to respond quickly is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of flood risk analysis, and in particular relates to a method and system for quickly calculating flood depth based on multi-layer grid overlay analysis. Background Art

[0002] In the context of frequent extreme rainstorms, urban flood prevention is particularly important. Flood risk analysis, as a key link in flood prevention, is of great significance for extending warning preparation time, improving the scientific nature of emergency response, and providing effective support for decision-making when rainstorms occur.

[0003] The inundation depth is an important indicator to measure the severity of floods and a key factor in flood risk assessment. In flood risk analysis, the calculation of inundation depth not only affects the accuracy and timeliness of early warning preparation, but is also directly related to the scientificity and effectiveness of emergency response.

[0004] However, in actual operation, the key problem and difficulty that restricts the effectiveness of flood risk analysis is to accurately calculate the flood depth based on the actual weather in a short period of time. At present, there are two main methods for calculating flood depth on the market: one is the emerging neural network and interdisciplinary model. Although such methods have certain innovation and flexibility, they face the problems of low accuracy and unstable results in practical applications; the other is the traditional hydrological and hydrodynamic professional model. Although such methods are mature in theory and rigorous in calculation process, they have large amount of calculation and low timeliness, which makes it difficult to meet the needs of rapid response. Summary of the invention

[0005] Purpose of the invention: In order to solve the above problems, the present invention provides a method and system for quickly calculating the submerged water depth based on multi-layer grid overlay analysis.

[0006] Technical solution: A fast calculation method for flooding depth based on multi-layer grid overlay analysis includes the following steps:

[0007] step S 1. Based on the same monitoring area, a meteorological grid, a watershed grid, and a hydrodynamic model grid are respectively established; the meteorological grid, the watershed grid, and the hydrodynamic model grid are respectively divided into a number of meteorological grid points, watershed divisions, and hydrodynamic model grid units;

[0008] step S 2. Analyze the grid superposition relationship between the meteorological grid points and the watershed partitions, and between the watershed partitions and the hydrodynamic model grid units to obtain analysis results; and update the analysis results to the distributed database;

[0009] step S 3. Get the current meteorological grid point The corresponding real-time rainfall is obtained from the distributed database by index query and the current meteorological grid point Current watershed partitions with overlapping relationships , and the current watershed partition Current hydrodynamic model grid cells with overlapping relationships ;

[0010] step S 4. Use the rainfall calculation formula to calculate the current basin division The corresponding rainfall ; Based on the rainfall , query the preset model solution table by index to obtain the corresponding rainfall interval and the maximum flooding depth value corresponding to the rainfall interval;

[0011] step S 5. Based on rainfall , rainfall interval, and the maximum flooding depth value corresponding to the rainfall interval are calculated to obtain the current hydrodynamic model grid unit The corresponding maximum flooding depth.

[0012] In a further embodiment, the step S 2 further comprises the following steps:

[0013] use GIS The technology performs geometric intersection operations on meteorological grids and watershed grids, and on watershed grids and hydrodynamic model grids, to obtain meteorological grid points and watershed partitions, as well as watershed partitions and hydrodynamic model grid units with overlapping relationships;

[0014] Assign corresponding serial numbers to meteorological grid points, watershed divisions, and hydrodynamic model grid cells;

[0015] Calculating the intersection area of ​​the meteorological grid points and the watershed partitions that have an overlapping relationship; updating the intersection area and the serial numbers of the meteorological grid points and the watershed partitions related to the intersection area into the distributed database;

[0016] The serial numbers of the watershed partitions and hydrodynamic model grid cells having overlapping relationships are updated in the distributed database.

[0017] In a further embodiment, the step S 4 medium rainfall The following rainfall calculation formula is used:

[0018] ;

[0019] In the formula, For watershed partitions, For watershed partition The corresponding rainfall amount; is the meteorological grid point, Meteorological grid point The corresponding real-time rainfall; For watershed partition The area of for and The intersection area.

[0020] In a further embodiment, the step S The establishment of the model scheme table in 4 includes the following steps:

[0021] Get watershed partitions The historical rainfall and the historical rainfall range ,in, This is the lowest rainfall in history. This is the highest rainfall in history.

[0022] The historical rainfall range Equidistant division n Segments, each segment interval is ,in, n is a parameter; the rainfall corresponding to the endpoint of each segment interval is defined as the preset rainfall and updated to the model scheme table;

[0023] The basin partition is calculated based on the preset rainfall corresponding to the endpoints of each segment interval. Corresponding hydrodynamic simulation grid cells Maximum flooding depths under different preset rainfall levels;

[0024] Hydrodynamic simulation grid cells The serial number and hydrodynamic simulation grid unit The maximum flooding depths under different preset rainfall amounts are updated in the model scenario table.

[0025] In a further embodiment, the step S 4. The corresponding rainfall interval and the maximum flooding depth value corresponding to the rainfall interval are obtained by index query; the following steps are included:

[0026] The current watershed partition is obtained by querying the index of the model scheme table The corresponding preset rainfall set ;

[0027] Based on rainfall , from a preset rainfall set Select the rainfall interval ; where the rainfall is defined Not greater than The maximum rainfall value is defined as is not less than The minimum rainfall ;

[0028] Based on rainfall , rainfall , respectively obtain the current hydrodynamic model grid cells In rainfall , Maximum flooding depth.

[0029] In a further embodiment, the step S 5 Current hydrodynamic model grid cells The corresponding maximum flooding depth is calculated using barycentric coordinate linear interpolation, and the calculation formula is as follows:

[0030] ;

[0031] ;

[0032] In the formula, The hydrodynamic model grid cell In rainfall Maximum flooding depth at 1000 km / h; , The hydrodynamic model grid cells are In rainfall , Maximum flooding depth at 1000 km / h; is the interpolation parameter.

[0033] In a further embodiment, the following steps are also included:

[0034] By using parallel computing technology, the barycentric coordinate interpolation calculation is performed for each hydrodynamic model grid cell within the corresponding rainfall range.

[0035] In another technical solution, a system for rapidly calculating submerged water depth based on multi-layer grid overlay analysis is provided, which is used to implement the method for rapidly calculating submerged water depth based on multi-layer grid overlay analysis as described above, and the system comprises:

[0036] The first module is configured to establish a meteorological grid, a watershed grid, and a hydrodynamic model grid based on the same monitoring area; the meteorological grid, the watershed grid, and the hydrodynamic model grid are respectively divided into a number of meteorological grid points, watershed divisions, and hydrodynamic model grid units;

[0037] The second module is configured to analyze the grid superposition relationship between the meteorological grid points and the watershed partitions, and between the watershed partitions and the hydrodynamic model grid units, to obtain analysis results; and update the analysis results to the distributed database;

[0038] The third module is set to obtain the current meteorological grid point The corresponding real-time rainfall is obtained from the distributed database by index query and the current meteorological grid point Current watershed partitions with overlapping relationships , and the current watershed partition Current hydrodynamic model grid cells with overlapping relationships ;

[0039] The fourth module is configured to calculate the current watershed partition using the rainfall calculation formula The corresponding rainfall ; Based on the rainfall , query the preset model solution table by index to obtain the corresponding rainfall interval and the maximum flooding depth value corresponding to the rainfall interval;

[0040] The fifth module is set based on rainfall , rainfall interval, and the maximum flooding depth value corresponding to the rainfall interval are calculated to obtain the current hydrodynamic model grid unit The corresponding maximum flooding depth.

[0041] Beneficial effects:

[0042] (1) The present invention pre-constructs a meteorological grid, a watershed grid, and a hydrodynamic model grid; uses the intersection area between the meteorological grid and the watershed grid as an allocation weight, and obtains real-time rainfall data to calculate the rainfall allocated to the watershed unit; and uses the overlapping relationship between the watershed grid and the hydrodynamic model grid and the rainfall allocated to the watershed unit to calculate the maximum flooding depth of the hydrodynamic model grid unit.

[0043] (2) The present invention uses the catchment area as the basic unit for rainfall allocation and accurately calculates the impact of rainfall on the depth of accumulated water. With the help of the spatial overlap relationship between the meteorological grid and the catchment area unit, the amount is allocated by weighting the intersection area. The spatial overlap relationship distributed database is used to quickly query the spatial overlap information through indexing, thereby accelerating real-time calculation.

[0044] (3) The present invention combines distributed database and parallel computing technology, and proposes a static-dynamic variable decoupling interpolation method to provide results that are relatively consistent with professional models in a short time. Through the organic combination of overlay analysis, distributed database, and parallel computing, it not only achieves accurate calculation of complex data analysis and simulation, but also ensures the ability to respond quickly.

[0045] Compared with the classical hydrological and hydrodynamic model, the present invention reduces the time cost to 1 / 12 and controls the absolute error within 5 cm More than 97.7% of the hydrodynamic model grid cells have an absolute error of less than 0.25 cm . BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a flow chart of the method of the present invention;

[0047] Figure 2 is a technical breakdown diagram of the present invention;

[0048] Figure 3 It is an example diagram of the spatial overlay relationship table and the model scheme table;

[0049] Figure 4 It is a schematic diagram of the meteorological grid and the catchment area grid;

[0050] Figure 5 It is a schematic diagram of the catchment area grid and the hydrodynamic model grid. DETAILED DESCRIPTION

[0051] Example 1

[0052] like Figures 1 to 5 As shown, this embodiment provides a method for quickly calculating the submerged water depth based on multi-layer grid overlay analysis, comprising the following steps:

[0053] step S 1. Based on the same monitoring area, a meteorological grid, a watershed grid, and a hydrodynamic model grid are respectively established; the meteorological grid, the watershed grid, and the hydrodynamic model grid are respectively divided into a number of meteorological grid points, watershed divisions, and hydrodynamic model grid units;

[0054] step S 2. Analyze the grid superposition relationship between the meteorological grid points and the watershed partitions, and between the watershed partitions and the hydrodynamic model grid units to obtain analysis results; and update the analysis results to the distributed database;

[0055] step S 3. Get the current meteorological grid point The corresponding real-time rainfall is obtained from the distributed database by index query and the current meteorological grid point Current watershed partitions with overlapping relationships , and the current watershed partition Current hydrodynamic model grid cells with overlapping relationships ;

[0056] step S4. Use the rainfall calculation formula to calculate the current basin division The corresponding rainfall ; Based on the rainfall , query the preset model solution table by index to obtain the corresponding rainfall interval and the maximum flooding depth value corresponding to the rainfall interval;

[0057] step S 5. Based on rainfall , rainfall interval, and the maximum flooding depth value corresponding to the rainfall interval are calculated to obtain the current hydrodynamic model grid unit The corresponding maximum flooding depth.

[0058] In step S 1, the meteorological grid is a two-dimensional cloud grid, which is usually composed of the following parts: (1) Grid points: Each grid point usually represents a geographic coordinate, such as longitude and latitude, and these points form a regular rectangular grid in two-dimensional space. (2) Meteorological variables: Meteorological data is stored at each grid point. In this embodiment, rainfall is used as meteorological data. The rainfall here can be based on observed measured data or the result calculated by a numerical weather forecast model. (3) Spatial resolution: The resolution of the grid determines the distance between grid points. Higher resolution means more grid points and more detailed meteorological data.

[0059] The catchment grid is the basic unit used in hydrological models to describe the convergence and distribution of water flow, and is usually used to simulate rainfall-runoff processes and flood forecasting. The catchment grid used in this embodiment mainly includes the following main parts: (1) Grid points: Similar to meteorological grids, the catchment grid is also composed of regular or irregular grid points. Each grid point represents a small unit in the catchment area and has specific geographical coordinates (such as longitude and latitude). (2) Basin division: divided into different basins, each basin represents an independent catchment area. By analyzing the water flow direction of the grid points, the boundary of each basin can be determined. (3) Precipitation: The grid points include precipitation data, which indicates the distribution of rainfall in each grid unit. Precipitation data can also come from measured data or numerical prediction models.

[0060] The hydrodynamic model grid is the basic unit used to simulate water flow and hydrodynamic processes, and is widely used in hydrological and hydrodynamic simulations such as rivers, reservoirs, lakes, and floods. In this embodiment, the hydrodynamic model grid consists of the following two main parts: (1) Grid cells: The two-dimensional hydrodynamic grid is composed of regular (such as rectangular) or irregular (such as triangular, quadrilateral) cells. Each cell represents a small two-dimensional spatial area in the simulation area and is used to calculate the hydrodynamic behavior in the area. (2) Maximum flooding depth: The water depth or water level information is recorded in each grid cell. Water depth is one of the key parameters for hydrodynamic calculations and determines the flow speed, direction, and flow rate of the water body in the grid.

[0061] step S 2 further comprises the following steps:

[0062] use GIS The technology performs geometric intersection operations on meteorological grids and watershed grids, and on watershed grids and hydrodynamic model grids, to obtain meteorological grid points and watershed partitions, as well as watershed partitions and hydrodynamic model grid units with overlapping relationships;

[0063] Assign corresponding serial numbers to meteorological grid points, watershed divisions, and hydrodynamic model grid cells;

[0064] Calculating the intersection area of ​​the meteorological grid points and the watershed partitions that have an overlapping relationship; updating the intersection area and the serial numbers of the meteorological grid points and the watershed partitions related to the intersection area into the distributed database;

[0065] The serial numbers of the watershed partitions and hydrodynamic model grid cells having overlapping relationships are updated in the distributed database.

[0066] That is to say, when studying the grid overlay relationship between meteorological grid points and watershed partitions, and between watershed partitions and hydrodynamic model grid units, first read the meteorological grid, watershed grid, and hydrodynamic model grid data and load them into the system; perform coordinate transformation on the meteorological grid, watershed grid, and hydrodynamic model grid to ensure that they are in the same coordinate system. Then use GIS The technology performs a geometric intersection operation on the meteorological grid and the watershed grid, obtains the grid cells of the overlapping part, and calculates the intersection area of ​​the overlapping part (the meteorological grid point in this embodiment refers to the meteorological grid cell); based on the weighted calculation and distribution of the intersection area of ​​the overlapping part, the rainfall of each watershed partition (watershed unit) is obtained.

[0067] Among them, the steps S 4 medium rainfall The following rainfall calculation formula is used:

[0068] ;

[0069] In the formula, For watershed partitions, For watershed partition The corresponding rainfall amount; is the meteorological grid point, Meteorological grid point The corresponding real-time rainfall; For watershed partition The area of for and The intersection area.

[0070] In studying the overlapping relationship between meteorological grid points and watershed divisions, watershed divisions and meteorological grid points Intersection Area For data groups greater than 0, Serial number, Serial number and The values ​​corresponding to the watershed partition number, meteorological grid point number, and intersection area fields are inserted into the distributed database in sequence. The example is as follows:

[0071] Create a spatial overlay relationship table in a distributed database, including the following fields and types:

[0072] Column name, type;

[0073] Basin partition number, int ;

[0074] Meteorological grid point number, int ;

[0075] The intersection area, double .

[0076] A distributed database is a database system that spans multiple physical or logical nodes. Its core purpose is to improve data availability, scalability, and fault tolerance through distributed storage and processing. PostgresSQL This single-node relational database is Postgres - BDR Extension package that provides some distributed storage, sharding, query distribution and replication functions.

[0077] In the above spatial overlay relationship table, the basin partition number, meteorological grid point number and intersection area correspond to each other. For real-time meteorological rainfall data, the basin partition number and meteorological grid point number are used as indexes to quickly query the intersection area, and then the rainfall calculation formula is used to calculate the rainfall of the basin partition, accelerating real-time calculation.

[0078] step SThe establishment of the model scheme table in 4 includes the following steps:

[0079] Get watershed partitions The historical rainfall and the historical rainfall range ,in, This is the lowest rainfall in history. This is the highest rainfall in history.

[0080] The historical rainfall range Equidistant division n Segments, each segment interval is ,in, n is a parameter; the rainfall corresponding to the endpoint of each segment interval is defined as the preset rainfall and updated to the model scheme table;

[0081] The basin partition is calculated based on the preset rainfall corresponding to the endpoints of each segment interval. Corresponding hydrodynamic simulation grid cells Maximum flooding depths under different preset rainfall levels;

[0082] Hydrodynamic simulation grid cells The serial number and hydrodynamic simulation grid unit The maximum flooding depths under different preset rainfall amounts are updated in the model scenario table.

[0083] Among the above n The value can be adjusted according to the interpolation fineness. n The larger the value, the more accurate the interpolation result. The rainfall value at the end point of each segment interval is used as the boundary condition of the hydrological and hydrodynamic professional model to simulate and calculate the historical maximum flooding depth of each hydrodynamic simulation grid unit.

[0084] The specific fields and type information of the model scheme table in the database are as follows:

[0085] Column name, type;

[0086] rainfall, double ;

[0087] Grid cell number, int ;

[0088] Maximum flood depth, double .

[0089] step S The corresponding rainfall interval and the maximum flooding depth value corresponding to the rainfall interval are obtained by querying the index in 4;

[0090] The following steps are involved:

[0091] The current watershed partition is obtained by querying the index of the model scheme table The corresponding preset rainfall set ;

[0092] Based on rainfall , from a preset rainfall set Select the rainfall interval ; where the rainfall is defined Not greater than The maximum rainfall value is defined as is not less than The minimum rainfall ;

[0093] Based on rainfall , rainfall , respectively obtain the current hydrodynamic model grid cells In rainfall , Maximum flooding depth.

[0094] In other words, the preset rainfall field of the model scenario table in the database is constructed B - Tree Index; real-time calculated rainfall for each watershed interval , search the model solution table for a value not greater than The maximum rainfall value is taken as the left endpoint value of the rainfall interval. The real-time calculated rainfall for each watershed interval , find in the model solution table that is not less than The minimum rainfall value is taken as the right endpoint of the rainfall interval. . Combine the left and right endpoints into a rainfall interval .

[0095] step S 5 Current hydrodynamic model grid cells The corresponding maximum flooding depth is calculated using barycentric coordinate linear interpolation, and the calculation formula is as follows:

[0096] ;

[0097] ;

[0098] In the formula, The hydrodynamic model grid cell In rainfall Maximum flooding depth at 1000 km / h; , The hydrodynamic model grid cells are In rainfall , Maximum flooding depth at 1000 km / h; is the interpolation parameter.

[0099] The overlapping relationship between the above-mentioned watershed partitions and the hydrodynamic model grid units is: Falling in the watershed Inside.

[0100] In addition, this embodiment also includes the following steps:

[0101] By using parallel computing technology, the barycentric coordinate interpolation calculation is performed for each hydrodynamic model grid cell within the corresponding rainfall range.

[0102] In parallel computing, the rainfall distribution of each watershed partition is calculated and the rainfall is obtained; for the rainfall of each watershed partition , query the database to obtain the corresponding rainfall interval . use GIS The overlay analysis obtains the overlay relationship between the hydrodynamic model grid and the catchment area grid; for the hydrodynamic model grid cells falling in the watershed partition, the maximum flooded water depth after the barycentric coordinate interpolation is calculated.

[0103] The interpolation calculation task of each hydrodynamic model grid cell is divided into different computing cores or processors. Each processor is responsible for calculating the interpolation of one or more hydrodynamic model grid cells.

[0104] Parallel computing can significantly reduce the total computing time; since each processor or computing core independently handles its assigned task, the overall calculation is performed simultaneously, thus speeding up the overall calculation. By assigning tasks to multiple processors, computing resources can be used more efficiently. In a multi-core processor or distributed computing environment, each core or node can fully utilize its computing power, avoiding the situation where a single processor is overloaded while other processors are idle.

[0105] Compared with the classical hydrological and hydrodynamic model, the method provided in this embodiment reduces the time cost to 1 / 12 and the absolute error is controlled within 5 cm More than 97.7% of the hydrodynamic model grid cells have an absolute error of less than 0.25 cm .

[0106] Example 2

[0107] This embodiment provides a system for quickly calculating submerged water depth based on multi-layer grid overlay analysis, which is used to implement the method for quickly calculating submerged water depth based on multi-layer grid overlay analysis as described in Example 1. The system includes:

[0108] The first module is configured to establish a meteorological grid, a watershed grid, and a hydrodynamic model grid based on the same monitoring area; the meteorological grid, the watershed grid, and the hydrodynamic model grid are respectively divided into a number of meteorological grid points, watershed divisions, and hydrodynamic model grid units;

[0109] The second module is configured to analyze the grid superposition relationship between the meteorological grid points and the watershed partitions, and between the watershed partitions and the hydrodynamic model grid units, to obtain analysis results; and update the analysis results to the distributed database;

[0110] The third module is set to obtain the current meteorological grid point The corresponding real-time rainfall is obtained from the distributed database by index query and the current meteorological grid point Current watershed partitions with overlapping relationships , and the current watershed partition Current hydrodynamic model grid cells with overlapping relationships ;

[0111] The fourth module is configured to calculate the current watershed partition using the rainfall calculation formula The corresponding rainfall ; Based on the rainfall , query the preset model solution table by index to obtain the corresponding rainfall interval and the maximum flooding depth value corresponding to the rainfall interval;

[0112] The fifth module is set based on rainfall , rainfall interval, and the maximum flooding depth value corresponding to the rainfall interval are calculated to obtain the current hydrodynamic model grid unit The corresponding maximum flooding depth.

Claims

1. A fast calculation method for submerged water depth based on multi-layer grid overlay analysis, characterized in that: The following steps are involved: step S 1. Based on the same monitoring area, a meteorological grid, a watershed grid, and a hydrodynamic model grid are respectively established; the meteorological grid, the watershed grid, and the hydrodynamic model grid are respectively divided into a number of meteorological grid points, watershed divisions, and hydrodynamic model grid units; step S 2. Analyze the grid superposition relationship between the meteorological grid points and the watershed partitions, and between the watershed partitions and the hydrodynamic model grid units to obtain analysis results; and update the analysis results to the distributed database; step S 3. Get the current meteorological grid point The corresponding real-time rainfall is obtained from the distributed database by index query and the current meteorological grid point Current watershed partitions with overlapping relationships , and the current watershed partition Current hydrodynamic model grid cells with overlapping relationships ; step S 4. Use the rainfall calculation formula to calculate the current basin division The corresponding rainfall ; Based on the rainfall , query the preset model solution table by index to obtain the corresponding rainfall interval and the maximum flooding depth value corresponding to the rainfall interval; step S 5. Based on rainfall , rainfall interval, and the maximum flooding depth value corresponding to the rainfall interval are calculated to obtain the current hydrodynamic model grid unit The corresponding maximum flooding depth; step S 4 medium rainfall The following rainfall calculation formula is used: ； In the formula, For watershed partitions, For watershed partition The corresponding rainfall amount; is the meteorological grid point, Meteorological grid point The corresponding real-time rainfall; For watershed partition The area of for and The intersection area.

2. The method for rapid calculation of submerged water depth based on multi-layer grid overlay analysis according to claim 1, characterized in that: step S 2 further comprises the following steps: use GIS The technology performs geometric intersection operations on meteorological grids and watershed grids, and on watershed grids and hydrodynamic model grids, to obtain meteorological grid points and watershed partitions, as well as watershed partitions and hydrodynamic model grid units with overlapping relationships; Assign corresponding serial numbers to meteorological grid points, watershed divisions, and hydrodynamic model grid cells; Calculating the intersection area of ​​the meteorological grid points and the watershed partitions that have an overlapping relationship; updating the intersection area and the serial numbers of the meteorological grid points and the watershed partitions related to the intersection area into the distributed database; The serial numbers of the watershed partitions and hydrodynamic model grid cells having overlapping relationships are updated in the distributed database.

3. The method for rapid calculation of submerged water depth based on multi-layer grid overlay analysis according to claim 2, characterized in that: step S The establishment of the model scheme table in 4 includes the following steps: Get watershed partitions The historical rainfall and the historical rainfall range ,in, This is the lowest rainfall in history. This is the highest rainfall in history. The historical rainfall range Equally divided into n Segments, each segment interval is ,in, n is a parameter; the rainfall corresponding to the endpoint of each segment interval is defined as the preset rainfall and updated to the model scheme table; The basin partition is calculated based on the preset rainfall corresponding to the endpoints of each segment interval. Corresponding hydrodynamic simulation grid cells Maximum flooding depths under different preset rainfall levels; Hydrodynamic simulation grid cells The serial number and hydrodynamic simulation grid unit The maximum flooding depths under different preset rainfall amounts are updated in the model scenario table.

4. The method for rapid calculation of submerged water depth based on multi-layer grid overlay analysis according to claim 3, characterized in that: step S The corresponding rainfall interval and the maximum flooding depth value corresponding to the rainfall interval are obtained by querying the index in 4; The following steps are involved: The current watershed partition is obtained by querying the index of the model scheme table The corresponding preset rainfall set ; Based on rainfall , from a preset rainfall set Select the rainfall interval ; where the rainfall is defined Not greater than The maximum rainfall value is defined as is not less than The minimum rainfall ; Based on rainfall , rainfall , respectively obtain the current hydrodynamic model grid cells In rainfall , Maximum flooding depth.

5. The method for rapid calculation of submerged water depth based on multi-layer grid overlay analysis according to claim 4, characterized in that: step S 5 Current hydrodynamic model grid cells The corresponding maximum flooding depth is calculated using barycentric coordinate linear interpolation, and the calculation formula is as follows: ； ； In the formula, The hydrodynamic model grid cell In rainfall Maximum flooding depth at 1000 km / h; , The hydrodynamic model grid cells are In rainfall , Maximum flooding depth at 1000 km / h; is the interpolation parameter.

6. The method for rapid calculation of submerged water depth based on multi-layer grid overlay analysis according to claim 5, characterized in that: The following steps are also included: By using parallel computing technology, the barycentric coordinate interpolation calculation is performed for each hydrodynamic model grid cell within the corresponding rainfall range.

7. A system for rapid calculation of submerged water depth based on multi-layer grid overlay analysis, used to implement a method for rapid calculation of submerged water depth based on multi-layer grid overlay analysis as claimed in any one of claims 1 to 6, characterized in that: The system comprises: The first module is configured to establish a meteorological grid, a watershed grid, and a hydrodynamic model grid based on the same monitoring area; the meteorological grid, the watershed grid, and the hydrodynamic model grid are respectively divided into a number of meteorological grid points, watershed divisions, and hydrodynamic model grid units; The second module is configured to analyze the grid superposition relationship between the meteorological grid points and the watershed partitions, and between the watershed partitions and the hydrodynamic model grid units, to obtain analysis results; and update the analysis results to the distributed database; The third module is set to obtain the current meteorological grid point The corresponding real-time rainfall is obtained from the distributed database by index query and the current meteorological grid point Current watershed partitions with overlapping relationships , and the current watershed partition Current hydrodynamic model grid cells with overlapping relationships ; The fourth module is configured to calculate the current watershed partition using the rainfall calculation formula The corresponding rainfall ; Based on the rainfall , query the preset model solution table by index to obtain the corresponding rainfall interval and the maximum flooding depth value corresponding to the rainfall interval; The fifth module is set based on rainfall , rainfall interval, and the maximum flooding depth value corresponding to the rainfall interval are calculated to obtain the current hydrodynamic model grid unit The corresponding maximum flooding depth.

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