A method and system for automatically identifying and extracting flood risk map elements
By using MIKE software and code conversion technology, the flood range, flood depth, flood duration and arrival time of flood risk maps are automatically identified, solving the problem of tedious manual analysis in existing technologies and realizing efficient and accurate flood risk map production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHANGJIANG SURVEY PLANNING DESIGN & RES CO LTD
- Filing Date
- 2026-01-23
- Publication Date
- 2026-05-29
AI Technical Summary
The current process of creating flood risk maps involves tedious manual analysis and calculations, resulting in long mapping cycles and high costs. There is an urgent need for automated identification of flood risk map elements to improve efficiency.
Flood simulations were performed using MIKE software. The simulation results were converted from .dfsu files to .shp files. Data processing and analysis were performed by writing code to automatically identify elements such as inundation range, inundation depth, inundation duration, and flood arrival time.
It has enabled the automated identification of flood risk map elements, improving accuracy, shortening the mapping cycle, reducing costs, and enhancing the timeliness of emergency response.
Smart Images
Figure CN122113723A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of element identification and extraction technology, and particularly relates to a method and system for automatic identification and extraction of flood risk map elements. Background Technology
[0002] A flood risk map is a thematic map compiled based on a geographic information system and hydrodynamic models. It scientifically marks the inundation range, inundation depth, inundation duration, and flood arrival time of floods with different return periods, intuitively displaying the flood risk distribution of a region. It can effectively support flood control emergency command and disaster relief, and provide a scientific basis for flood control management.
[0003] Current flood risk map production processes require manual analysis and calculations based on hydrodynamic simulations, combining the simulation results with geographic information data to obtain elements such as flood inundation range, inundation depth, inundation duration, and flood arrival time. This process is complex and one of the most time-consuming steps in the entire mapping cycle. There is an urgent need to propose a method for automatically identifying and extracting flood risk map elements to significantly improve mapping efficiency, freeing manpower from tedious post-processing, shortening the overall flood risk map production cycle, and reducing costs. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this disclosure provides a method for automatically identifying and extracting flood risk map elements. The method involves using MIKE software to perform flood simulation, converting the .dfsu simulation results into .shp files, and then writing code to process and analyze the simulation results, thereby achieving automatic identification and extraction of flood risk map elements such as inundation range, inundation depth, inundation duration, and flood arrival time.
[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for automatically identifying and extracting flood risk map elements includes the following steps: Collect basic geographic and hydrodynamic data of the study area, simulate flood evolution based on the hydrodynamic model, and output flood inundation process data and maximum inundation value data for each grid cell in the simulation area; The maximum inundation data is converted to generate a standardized vector geographic data file with spatial topology and attribute information. Based on the standardized vector geographic data file, the flood inundation range is identified and extracted through spatial analysis and hydrological identification. Based on the standardized vector geographic data file, the flood inundation depth distribution is extracted; Based on the standardized vector geographic data file, the flood inundation duration distribution is extracted; Based on the flood inundation process data, the arrival time distribution of the flood is extracted; By integrating the flood inundation range, inundation depth distribution, inundation duration distribution, and flood arrival time distribution, a flood risk map is generated.
[0006] Furthermore, the maximum flooding data undergoes format conversion, including attribute reconstruction, geometric topology conversion, and geocoding, to achieve the conversion from model result format to vector geographic data format.
[0007] Furthermore, the model results are in .dfsu format, and the general vector geographic data are in .shp format.
[0008] Furthermore, the specific steps for identifying and extracting the flood inundation range include: Read the maximum water depth attribute of each grid cell in the standardized vector geographic data file; Based on a preset water depth threshold, distinguish between flooded and non-flooded areas; The total area of all inundated grid areas is calculated as the flood inundation range.
[0009] Furthermore, the specific steps for automatically extracting the flood inundation depth distribution include: directly extracting the maximum water depth attribute value of each grid cell in the standardized vector geographic data file to form the inundation depth distribution.
[0010] Furthermore, the specific steps for extracting the duration distribution of flood inundation include: Read the flooding duration attribute of each grid cell in the standardized vector geographic data file; Extract all grid cells with a duration greater than zero and their corresponding duration values to form the flooding duration distribution.
[0011] Furthermore, the specific steps for extracting the arrival time distribution of the flood include: Read the water depth values of each grid cell at different time steps in the flood inundation process data; Identify the time step at which the water depth first exceeds zero in each grid cell; The first flooding time of each grid cell is taken as the flood arrival time, forming a spatiotemporal distribution.
[0012] Furthermore, the hydrodynamic model is a MIKE series model, and the standardized vector geographic data file is a shp format file.
[0013] Furthermore, the maximum inundation data is converted to a new format, and the inundation range, inundation depth distribution, inundation duration distribution, and flood arrival time distribution are extracted, along with the risk map generation. The entire process is automated and processed in batches through a written program script.
[0014] On the other hand, the present invention provides an automatic identification and extraction system for flood risk map elements, comprising the following steps: The data collection and simulation module is used to collect basic geographic and hydrodynamic data of the study area, simulate flood evolution based on the hydrodynamic model, and output flood inundation process data and maximum inundation value data for each grid cell in the simulation area. The data format conversion module is used to convert the maximum flooding data into a standardized vector geographic data file with spatial topology and attribute information. The inundation range extraction module is used to identify and extract the inundation range of floods based on the standardized vector geographic data file through spatial analysis and hydrological identification. The flood depth extraction module is used to extract the flood depth distribution based on the standardized vector geographic data file. The inundation duration extraction module is used to extract the inundation duration distribution of floods based on the standardized vector geographic data file. The arrival time extraction module is used to extract the arrival time distribution of the flood based on the flood inundation process data; The output module integrates the flood inundation range, inundation depth distribution, inundation duration distribution, and flood arrival time distribution to generate a flood risk map.
[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The method for automatic identification and extraction of flood risk map elements of the present invention can automatically identify and extract elements such as inundation range, inundation depth, inundation duration and flood arrival time, which is more accurate than previous studies.
[0016] 2. The method for automatic identification and extraction of flood risk map elements of the present invention can automatically identify and extract elements such as inundation range, inundation depth, inundation duration and flood arrival time in batches, shortening the overall production cycle of flood risk maps and reducing costs.
[0017] 3. The method for automatic identification and extraction of flood risk map elements of the present invention realizes the automatic conversion between hydrodynamic model result files and geographic information system files through code, which significantly improves the practicality and timeliness of the flood risk map production process, enabling it to better serve scientific decision-making for emergency response and disaster prevention and mitigation. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0019] Figure 1 A flowchart illustrating the method for automatic identification and extraction of flood risk map elements provided in this embodiment of the disclosure; Figure 2 The result of automatic identification and extraction of flood risk map elements provided in this embodiment of the disclosure (taking the inundation depth element as an example). Detailed Implementation
[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0021] In specific implementation, the method proposed in the technical solution of this invention can be automatically executed by those skilled in the art using computer software technology. System devices for implementing the method, such as computer-readable storage media storing the corresponding computer program of the technical solution of this invention and computer equipment including the computer program running the corresponding computer program, should also be within the protection scope of this invention.
[0022] Example 1 like Figure 1 As shown in the figure, this embodiment provides a method for automatic identification and extraction of flood risk map elements, including the following steps: Step 1: Collect basic geographic and hydrodynamic data of the study area, simulate flood evolution based on the hydrodynamic model, and output flood inundation process data and maximum inundation value data for each grid cell in the simulation area; Step 2: Convert the maximum inundation data to generate a standardized vector geographic data file with spatial topology and attribute information; Step 3: Based on the standardized vector geographic data file, identify and extract the flood inundation range through spatial analysis and hydrological identification; Step 4: Based on the standardized vector geographic data file, extract the flood inundation depth distribution; Step 5: Based on the standardized vector geographic data file, extract the flood inundation duration distribution; Step Six: Based on the flood inundation process data, extract the flood arrival time distribution; Step 7: Integrate the flood inundation range, inundation depth distribution, inundation duration distribution, and flood arrival time distribution to generate a flood risk map.
[0023] In step one of this embodiment, hydrodynamic simulation of the study area is performed based on MIKE software. The inputs to the hydrodynamic simulation are topographic data, upstream flow boundary data, and downstream water level boundary data. The outputs are the flood inundation process and maximum inundation value results for each grid cell in the study area over time steps.
[0024] In step two of this embodiment, a spatial data processing algorithm is written using Matlab to automatically and accurately convert the maximum inundation result (.dfsu format) output by MIKE software into a standardized vector geographic data file (.shp format) with spatial topology and complete attribute information, which is used for subsequent extraction of inundation range, inundation depth and inundation duration results; The specific steps for converting the flood maximum value output from the MIKE software in step two are as follows: Step 2-1: Perform attribute reconstruction, geometric topology transformation, and geocoding output for .dfsu format files: (1) (2) (3) In the formula, For .shp format files, For .dfsu format files, This is a .shp file after geometric topology conversion. This is the final .shp format file after geocoding output.
[0025] In step three of this embodiment: Python code is used to perform spatial analysis and in-depth processing on .shp format files, constructing an automated modeling process. This involves defining hydrological identification thresholds and extracting the flood inundation range. The specific steps are as follows: Step 3-1: The system interprets the attribute structure of the .shp format file and extracts the Maximum water depth field of each grid cell in the maximum flooding result .shp file; Step 3-2: Determine if the Maximum water depth field value of each grid cell is greater than 0; define grid cells with a Maximum water depth field value greater than 0 as flooded areas, and define grid cells with a Maximum water depth field value equal to 0 as non-flooded areas; Step 3-3: Calculate the area of grid cells with a Maximum water depth field value greater than 0 to obtain the flood inundation range. (4) (5) In the formula, S inundated For the set of submerged grid cells, G The set of all grid cells. d i For grid cells i The value of the Maximum water depth field. A The area of a single grid cell. A total This refers to the extent of the floodwaters.
[0026] In step four of this embodiment, the specific steps for extracting the flood inundation depth are as follows: Step 4-1: The system interprets the attribute structure of the .shp format file and extracts the Maximum water depth field of each grid cell in the flood maximum result .shp file; Step 4-2: Count the grid cells with a Maximum water depth field value greater than 0 to obtain the flood inundation depth, such as... Figure 2 As shown.
[0027] In step five of this embodiment, Python code is used to perform spatial analysis and in-depth processing on .shp format files, constructing an automated modeling process. This involves defining hydrological identification thresholds and extracting the inundation duration of floods. The specific steps are as follows: Step 5-1: The system interprets the attribute structure of the .shp format file and extracts the Duration above threshold field of each grid cell in the flood maximum value result .shp file; Step 5-2: Count the grid cells with a value greater than 0 in the Duration above threshold field to obtain the flood inundation duration.
[0028] In step six of this embodiment, the specific steps for extracting the flood arrival time are as follows: Step 6-1: System interprets the attribute structure of the flooding process results .dfsu file and extracts the Maximum water depth field for each grid cell; Step 6-2: Determine whether the Total water depth field value of each grid cell is greater than 0 at each time step, and count the time step at which the Total water depth field value of each grid cell first appears to be greater than 0; Step 6-3: Calculate the time step in which the Total water depth field value is greater than 0 for the first time in each grid cell to obtain the flood arrival time; (6) In the formula, T i For grid cells i The arrival time of the flood t The number of time steps. t total This represents the total number of time steps. For grid cells i time step t The value of the Total water depth field.
[0029] Step 7: Use statistical data on inundation range, inundation depth, inundation duration, and flood arrival time to create a flood risk map.
[0030] Example 2 This embodiment provides an automatic identification and extraction system for flood risk map elements, including the following steps: The data collection and simulation module is used to collect basic geographic and hydrodynamic data of the study area, simulate flood evolution based on the hydrodynamic model, and output flood inundation process data and maximum inundation value data for each grid cell in the simulation area. The data format conversion module is used to convert the maximum flooding data into a standardized vector geographic data file with spatial topology and attribute information. The inundation range extraction module is used to identify and extract the inundation range of floods based on the standardized vector geographic data file through spatial analysis and hydrological identification. The flood depth extraction module is used to extract the flood depth distribution based on the standardized vector geographic data file. The inundation duration extraction module is used to extract the inundation duration distribution of floods based on the standardized vector geographic data file. The arrival time extraction module is used to extract the arrival time distribution of the flood based on the flood inundation process data; The output module is used to integrate the flood inundation range, inundation depth distribution, inundation duration distribution, and flood arrival time distribution to generate a flood risk map. It should be understood that any parts not described in detail in this specification belong to the prior art.
[0031] It should be understood that the above description of the preferred embodiments is quite detailed, but this should not be construed as limiting the scope of protection of this invention. It is neither necessary nor possible to exhaustively describe all possible implementations. Those skilled in the art, guided by this invention, can make substitutions or modifications without departing from the scope of the claims, all of which fall within the scope of protection of this invention. The scope of protection of this invention should be determined by the appended claims.
Claims
1. A method for automatic identification and extraction of flood risk map elements, characterized in that, Includes the following steps: Collect basic geographic and hydrodynamic data of the study area, simulate flood evolution based on the hydrodynamic model, and output flood inundation process data and maximum inundation value data for each grid cell in the simulation area; The maximum inundation data is converted to generate a standardized vector geographic data file with spatial topology and attribute information. Based on the standardized vector geographic data file, the flood inundation range is identified and extracted through spatial analysis and hydrological identification. Based on the standardized vector geographic data file, the flood inundation depth distribution is extracted; Based on the standardized vector geographic data file, the flood inundation duration distribution is extracted; Based on the flood inundation process data, the arrival time distribution of the flood is extracted; By integrating the flood inundation range, inundation depth distribution, inundation duration distribution, and flood arrival time distribution, a flood risk map is generated.
2. The method for automatic identification and extraction of flood risk map elements according to claim 1, characterized in that, The format conversion of the maximum inundation data includes attribute reconstruction, geometric topology transformation and geocoding, to achieve the conversion from model result format to vector geographic data format.
3. The method for automatic identification and extraction of flood risk map elements according to claim 2, characterized in that, The model results are in .dfsu format, and the general vector geographic data are in .shp format.
4. The method for automatic identification and extraction of flood risk map elements according to claim 1, characterized in that, The specific steps for identifying and extracting the flood inundation range include: Read the maximum water depth attribute of each grid cell in the standardized vector geographic data file; Based on a preset water depth threshold, distinguish between flooded and non-flooded areas; The total area of all inundated grid areas is calculated as the flood inundation range.
5. The method for automatic identification and extraction of flood risk map elements according to claim 1, characterized in that, The specific steps for automatically extracting the flood inundation depth distribution include: directly extracting the maximum water depth attribute value of each grid cell in the standardized vector geographic data file to form the inundation depth distribution.
6. The method for automatic identification and extraction of flood risk map elements according to claim 1, characterized in that, The specific steps for extracting the duration distribution of flood inundation include: Read the flooding duration attribute of each grid cell in the standardized vector geographic data file; Extract all grid cells with a duration greater than zero and their corresponding duration values to form the flooding duration distribution.
7. The method for automatic identification and extraction of flood risk map elements according to claim 1, characterized in that, The specific steps for extracting the arrival time distribution of floodwaters include: Read the water depth values of each grid cell at different time steps in the flood inundation process data; Identify the time step at which the water depth first exceeds zero in each grid cell; The first flooding time of each grid cell is taken as the flood arrival time, forming a spatiotemporal distribution.
8. The method for automatic identification and extraction of flood risk map elements according to claim 1, characterized in that, The hydrodynamic model is a MIKE series model, and the standardized vector geographic data file is a shp format file.
9. The method for automatic identification and extraction of flood risk map elements according to claim 1, characterized in that, The maximum inundation data is converted into a new format, and the inundation range, inundation depth distribution, inundation duration distribution, and flood arrival time distribution are extracted. A risk map is also generated. The entire process is automated and processed in batches through a written program script.
10. An automatic identification and extraction system for flood risk map elements, characterized in that, Includes the following steps: The data collection and simulation module is used to collect basic geographic and hydrodynamic data of the study area, simulate flood evolution based on the hydrodynamic model, and output flood inundation process data and maximum inundation value data of each grid cell in the simulation area. The data format conversion module is used to convert the maximum flooding data into a standardized vector geographic data file with spatial topology and attribute information. The inundation range extraction module is used to identify and extract the inundation range of floods based on the standardized vector geographic data file through spatial analysis and hydrological identification. The flood depth extraction module is used to extract the flood depth distribution based on the standardized vector geographic data file. The inundation duration extraction module is used to extract the inundation duration distribution of floods based on the standardized vector geographic data file. The arrival time extraction module is used to extract the arrival time distribution of the flood based on the flood inundation process data; The output module is used to integrate the flood inundation range, inundation depth distribution, inundation duration distribution, and flood arrival time distribution to generate a flood risk map. The automatic identification and extraction system for flood risk map elements is used to perform the steps in the automatic identification and extraction method for flood risk map elements according to any one of claims 1-9.