Method and system for measuring shortest distance from earthquake epicenter to reservoir water sideline

Abstract

The invention discloses a method and a system for measuring the shortest distance from an earthquake epicenter to a reservoir water sideline. The method comprises the following steps: acquiring earthquake event data of a reservoir monitoring area; extracting a high-precision electronic map containing the reservoir monitoring area from the standard electronic map; feature colors are given to reservoir elements in the high-precision electronic map, and a feature electronic map only containing the feature colors is obtained; performing digital processing on the characteristic electronic map to obtain latitude and longitude coordinates of each pixel point of the reservoir water side line of the reservoir in the characteristic electronic map; and determining the shortest distance from the earthquake epicenter to the reservoir water boundary according to the earthquake event data and the latitude and longitude coordinates of each pixel point of the reservoir water boundary. The measurement method is simple and efficient, the measurement result is high in precision, a reliable result is provided for statistical analysis of the seismic events in the reservoir influence area, and the defects of a traditional method are effectively overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of earthquake monitoring and analysis, and in particular relates to a method and a system for measuring the shortest distance from an earthquake epicenter to a reservoir water edge. Background Art

[0002] Reservoir earthquakes are earthquakes in the reservoir area and adjacent areas (the range of reservoir water influence) caused by the storage of water or changes in water levels. After the reservoir is built and filled with water, the loading and unloading process and the infiltration process of the reservoir water may induce medium-strong or above reservoir earthquakes in the reservoir area and surrounding areas. According to regulations, new reservoirs with a dam height of more than 100 meters and a storage capacity of more than 500 million cubic meters should build reservoir earthquake monitoring networks and carry out reservoir earthquake monitoring. For this reason, a large number of water conservancy and hydropower projects have built special reservoir earthquake monitoring networks to monitor earthquake activities in the reservoir area and surrounding areas.

[0003] According to the definition in "Reservoir Induced Earthquake Hazard Assessment" GB 21075-2007, the reservoir influence zone is the reservoir area and its extension of 10km. This standard does not provide scientific data support. In actual application, the scope of the reservoir influence zone is not clear enough due to the different geological conditions of the reservoir and the amplitude of the water level in front of the dam. The reservoir earthquake monitoring network has recorded a large number of earthquake events related to reservoir storage and precipitation activities in the monitoring area, laying the foundation for the statistical analysis of the influence area of ​​different reservoirs. Therefore, conducting quantitative statistical analysis of the distance between the epicenter of the earthquake and the reservoir water edge before and after the water storage of different reservoirs is of great significance for the accurate definition of the scope of the reservoir influence area and the study of the distribution law of reservoir earthquakes.

[0004] Reservoirs vary in shape, some are curved, and some are straight. It is difficult to measure the shortest distance from the epicenter of an earthquake to the water edge of the reservoir, and then analyze the impact range after the reservoir is filled with water. At present, the traditional method of calculating the shortest distance from the epicenter of an earthquake to the water edge of the reservoir is manual measurement, which is calculated by a scale. The steps are: S1 draw an earthquake distribution map in the reservoir monitoring area; S2 use a ruler to measure the shortest distance from the epicenter to the water edge of the reservoir; S3 convert the distance from the epicenter to the water edge of the reservoir according to the scale; S4 manually count the shortest distance from the epicenter of all earthquakes to the water edge of the reservoir. This method is cumbersome, time-consuming, has large errors, and is only applicable to earthquake events of small magnitude, and cannot accurately reflect the shortest distance from the epicenter of the earthquake to the water edge of the reservoir. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and to provide a method and system for quickly and accurately measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir.

[0006] The technical solution adopted by the present invention is: a method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir, comprising the following steps:

[0007] Obtain earthquake event data in the reservoir monitoring area;

[0008] Extracting a high-precision electronic map containing the reservoir monitoring area from a standard electronic map;

[0009] Assigning characteristic colors to reservoir elements in the high-precision electronic map to obtain a characteristic electronic map containing only the characteristic colors;

[0010] Digital processing is performed on the characteristic electronic map to obtain the longitude and latitude coordinates of each pixel point of the reservoir water edge line in the characteristic electronic map;

[0011] The shortest distance from the earthquake epicenter to the reservoir water edge is determined based on the earthquake event data and the longitude and latitude coordinates of each pixel point on the reservoir water edge.

[0012] Furthermore, the type of the standard electronic map is any one of Amap, Tencent Map, and Baidu Map.

[0013] Furthermore, the process of extracting a high-precision electronic map containing the reservoir monitoring area from the standard electronic map is as follows:

[0014] Determine the type and tile level of standard electronic maps;

[0015] Calculate the coordinates of the boundary tile map of the reservoir monitoring area according to the latitude and longitude range and tile level of the reservoir monitoring area;

[0016] Obtaining coordinates of all tile maps and tile maps including the reservoir monitoring area from the standard electronic map according to the coordinates of the boundary tile map;

[0017] All tile maps are successively spliced ​​based on the principle of tile coordinate proximity to obtain a high-precision electronic map covering the reservoir monitoring area.

[0018] Furthermore, the coordinates of the boundary tile map of the reservoir monitoring area are calculated by the following formula:

[0019]

[0020] Among them, (tileX, tileY) is the coordinate of the boundary tile map of the reservoir monitoring area, Level is the tile level, and (pointX, pointY) is the latitude and longitude coordinates of the boundary point of the reservoir monitoring area.

[0021] Furthermore, the process of digitizing the characteristic electronic map is as follows: extracting the reservoir water edge line of the reservoir in the characteristic electronic map, obtaining the pixel coordinates of each pixel point on the reservoir water edge line, and converting the pixel coordinates of each pixel point on the reservoir water edge line into longitude and latitude coordinates through a coordinate conversion formula.

[0022] Furthermore, the coordinate transformation formula is:

[0023] Ing=(pixelX / X)×(lng2-lng1)+lng1

[0024] lat=(pixelY / Y)×(lat2-lat1)+lat1

[0025] Among them, (lng, lat) are the longitude and latitude coordinates of the corresponding pixel point on the reservoir water edge; X and Y are the pixel values ​​of the feature electronic map, (pixelX, pixelY) are the pixel coordinates of the corresponding pixel point on the reservoir water edge, lng1 and lng2 are the lower limit and upper limit of the longitude range of the high-precision electronic map, and lat1 and lat2l are the lower limit and upper limit of the latitude range of the high-precision electronic map.

[0026] Furthermore, the distance from the earthquake epicenter to the reservoir water edge is calculated using the distance calculation formula between two points in the longitude and latitude coordinate system, and the calculated distances are compared, with the minimum distance being taken as the shortest distance from the earthquake epicenter to the reservoir water edge.

[0027] Furthermore, the distance calculation formula between two points in the latitude and longitude coordinate system is:

[0028]

[0029] Among them, S is the distance from the epicenter of the earthquake to the corresponding pixel point on the reservoir water edge, (x1, y1) is the longitude and latitude coordinates of the epicenter of the earthquake, (x2, y2) is the longitude and latitude coordinates of the corresponding pixel point on the reservoir water edge, and r is the radius of the earth.

[0030] Furthermore, after determining the shortest distance from the earthquake epicenter to the reservoir water edge, a distance calculation result file is generated based on the earthquake event data; at the same time, the spatial interval of the shortest distance from the earthquake epicenter to the reservoir water edge is set to generate a distance frequency statistics file.

[0031] A system for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir, comprising

[0032] A data acquisition module, used to acquire earthquake event data including the reservoir monitoring area;

[0033] A map extraction module is used to extract a high-precision electronic map including the reservoir monitoring area from a standard electronic map;

[0034] The feature calibration map module assigns characteristic colors to the reservoir elements in the high-precision electronic map to obtain a characteristic electronic map containing only the characteristic colors;

[0035] A digital map module is used to digitize the characteristic electronic map to obtain the longitude and latitude coordinates of each pixel point of the reservoir water edge line in the characteristic electronic map;

[0036] The distance calculation module is used to determine the shortest distance from the earthquake epicenter to the reservoir water edge based on the earthquake event data and the longitude and latitude coordinates of each pixel point on the reservoir water edge.

[0037] The beneficial effects of the present invention are:

[0038] The present invention extracts a high-precision electronic map including the latitude and longitude range of the reservoir monitoring area from a standard electronic map by splicing tile maps; defines characteristic colors of reservoir elements in the high-precision electronic map, and performs edge detection to realize the digitization of reservoir elements in the high-precision electronic map; and then combines earthquake event data and the digitized high-precision electronic map file to quickly obtain the shortest distance from the earthquake epicenter to the reservoir water edge. The measurement method is simple and efficient, and the measurement result has high accuracy, which can provide reliable results for statistical analysis of earthquake events in the reservoir influence area, and effectively makes up for the defects and shortcomings of traditional methods.

[0039] The present invention can realize the rapid, batch and accurate determination of the shortest distance from the epicenter of an earthquake to the water edge of a reservoir, as well as the intelligent classification and automatic output of data results. It is an automated and intelligent distance measurement method.

[0040] The map types of the present invention are diverse and can be selected, with strong timeliness, flexible and convenient operation, and can meet personalized needs.

[0041] The present invention performs digital processing on the characteristic electronic map, defines the clear position of each pixel point as the pixel coordinate where it is located, and does not change the pixel point attributes of the electronic map during the digital processing of the characteristic map, thereby ensuring the accuracy of the calculation result. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The present invention is a flow chart of the method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir.

[0043] Figure 2 Schematic diagram of the format of seismic data obtained in an embodiment of the present invention.

[0044] Figure 3 Schematic diagram of Amap tile coordinate numbering in an embodiment of the present invention (level=2).

[0045] Figure 4 It is a schematic diagram of a high-precision electronic map of a reservoir monitoring area of ​​a hydropower station in an embodiment of the present invention.

[0046] Figure 5 It is a schematic diagram of defining the characteristic colors of a reservoir in a monitoring area of ​​a hydropower station in an embodiment of the present invention.

[0047] Figure 6This is a schematic diagram of a result file of the shortest distance from the earthquake epicenter to the reservoir water edge generated in an embodiment of the present invention.

[0048] Figure 7 It is a schematic diagram of distance classification statistical results derived according to setting parameters in an embodiment of the present invention.

[0049] Figure 8 It is a schematic diagram of the statistical results of the monthly earthquake activity frequency in the reservoir monitoring area in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] Example:

[0052] like Figure 1 As shown, the present embodiment provides a method for measuring the shortest distance from the epicenter of an earthquake to the reservoir water edge, comprising the following steps:

[0053] S1: Obtain earthquake event catalog files, i.e., earthquake event data mentioned above, by downloading or other means. Specifically, the earthquake event catalog of the reservoir monitoring area can be downloaded from MapSIS. The contents of the earthquake event catalog are as follows: Figure 2 shown.

[0054] MapSIS is a GIS-based earthquake analysis and prediction system, which is used to realize the comprehensive analysis of earthquake activities, earthquake precursor data, geological structure conditions, geophysical environment and other spatial information. The system is based on database and knowledge base, with GIS as the pillar, analysis and prediction methods as the center, dynamic demonstration of results as the decoration, and supplemented by tools and help to form a complete software system.

[0055] The "earthquake event directory" is usually a txt file, which includes information such as number, year, month, day, hour, minute, second, latitude (degrees), longitude (degrees), magnitude, depth and place name.

[0056] S2: Extract a high-precision electronic map (including the corresponding longitude and latitude range) containing the reservoir earthquake monitoring area from the standard electronic map. The "reservoir earthquake monitoring area" is the area within the reservoir influence area and the surrounding 50km area where earthquakes of magnitude 5 or above have occurred in history. In this embodiment, the longitude range of the reservoir earthquake monitoring area is 102°E~103.8°E and the latitude range is 25.8°E.

[0057] N~28°N, complete the map selection, coordinate conversion and tile coordinate calculation in this range, obtain the tile map of the corresponding area, splice the tile map and generate the overall map, and realize the acquisition of high-precision electronic map, which specifically includes the following steps:

[0058] S21: Standard electronic map selection: You can choose any one of the types such as Amap, Google Map, Tencent Map, Baidu Map, etc. In this embodiment, Amap is selected as the map source, and the regional electronic map of the reservoir key monitoring area is selected from the web page address (URL, Uniform Resource Locator) provided by Amap. It should be pointed out that the online maps of Internet map service providers are provided in the form of tiles, that is, tile map services. The most common map tiles are in picture format. Map tiles have unique tile levels (Level) and tile coordinates (tileX, tileY). The higher the tile level, the more tiles make up the world map, the more detailed the displayed map is, and the higher the display accuracy. At a certain tile level Level, the X-axis and Y-axis of the tile coordinates each have 2^Level tile numbers, and the total number of tiles on the tile map is 2^Level*2^Level. Figure 3 As shown (the figure shows the tile coordinates when level = 2).

[0059] S22: Coordinate conversion and tile coordinate calculation: According to the longitude range of 102°E~103.8°E and latitude range of 25.8°N~28°N of the key monitoring area of ​​the reservoir, the tile level is given

[0060] (Level), is converted into the coordinates (tileX, tileY) of the boundary tile map of the reservoir monitoring area through the following coordinate conversion formula. In this embodiment, Level=13 is selected, and the pixel resolution is about 17m.

[0061]

[0062] Among them, (tileX, tileY) is the coordinate of the boundary tile map of the reservoir monitoring area, Level is the tile level, and (pointX, pointY) is the longitude and latitude coordinate of the boundary point of the reservoir monitoring area. According to the longitude and latitude range of the reservoir monitoring area, the reservoir monitoring area is displayed as a rectangular range on the map, and the boundary points of the reservoir monitoring area are the four corners of the rectangle. In this embodiment, the possible values ​​of (pointX, pointY) are (102°, 28°), (102°, 25.8°), (103.8°, 25.8°), and (103.8°, 28°). In actual calculation, only the two diagonal boundary points of the rectangle (i.e., the upper left corner and lower right corner or the upper right corner and lower left corner of the reservoir monitoring area) are taken to obtain the coordinates of the required boundary tile map.

[0063] It should be pointed out that the conversion between the longitude and latitude coordinates of a certain Internet map and tile coordinates is only related to the definition of the Mercator projection and tile number of the map vendor, and has nothing to do with the geodetic coordinate system standard used by the map vendor. Longitude and latitude coordinates can be directly converted to tile coordinates. All coordinate conversions are performed at a certain tile level, and the conversion results at different tile levels are different.

[0064] S23: Acquisition of tile maps of corresponding areas: Based on the coordinates (tileX, tileY) of the boundary tile map obtained in step S22, all tile maps and tile map coordinates including the reservoir monitoring area are acquired from the standard electronic map. The coordinates of the boundary tile map are the two tile map coordinates at opposite corners of the high-precision electronic map including the reservoir monitoring area, so a rectangular box is selected on the standard electronic map based on the two boundary tile map coordinates, and all tile maps within the rectangular box are the required tile maps.

[0065] S24: Tile map stitching and overall map generation: Based on the principle of tile map coordinates being adjacent, all tile maps obtained in step S23 are stitched together into a whole, thereby obtaining a high-precision electronic map with a pixel matrix of X×Y, whose longitude range is lng1~lng2 and latitude range is lat1~lat2, such as Figure 4 shown.

[0066] Generally, Mercator projection is often used in Internet maps. The map range can be determined by the longitude and latitude coordinates of the upper left corner and the lower right corner. At the same time, each tile map has a certain longitude and latitude range. Therefore, the pixel point matrix obtained by splicing this method is a high-precision electronic map of X×Y. The longitude and latitude range corresponds to the range controlled by all tiles (lng1~lng2, lat1~lat2), which includes the reservoir monitoring area.

[0067] S3: Based on the high-precision electronic map obtained in step S2, the reservoir range is selected. The main method is to use mapping software to define the characteristic color of the reservoir area (including the river) and generate a characteristic electronic map after the characteristic color is defined and only contains the characteristic color, such as Figure 5 shown.

[0068] S4: digitizing the reservoir elements of the characteristic electronic map generated in step S3 to generate a data file consisting of the longitude and latitude coordinates of the pixel points of the reservoir water edge. The process of digitizing the reservoir elements of the characteristic electronic map includes coordinate conversion of the pixel points of the reservoir water edge and longitude and latitude conversion of the pixel points of the reservoir water edge, and specifically includes the following steps:

[0069] S41: Coordinate conversion of pixel points on the water edge of the reservoir: extract the characteristic color in the characteristic electronic map defined in step S3, perform edge detection, and obtain the pixel coordinates (pixelX, pixelY) of each pixel point on the water edge of the reservoir.

[0070] S42: Conversion of longitude and latitude of pixel points on the water edge of the reservoir: Based on the longitude range lng1~lng2 and latitude range lat1~lat2 of the high-precision electronic map obtained in step S2, according to the following coordinate conversion formula, the conversion of the pixel coordinates (pixelX, pixelY) of the water edge of the reservoir is completed to the longitude and latitude coordinates (lng, lat), and a data file consisting of the longitude and latitude coordinates of the pixel points on the water edge of the reservoir is generated.

[0071] lng=(pixelX / X)×(mg2-lng1)+lng1

[0072] lat=(pixelY / Y)×(lat2-lat1)+lat1

[0073] Among them, (lng, lat) are the longitude and latitude coordinates of the corresponding pixel point on the reservoir water edge; X and Y are the pixel values ​​of the feature electronic map, (pixelX, pixelY) are the pixel coordinates of the corresponding pixel point on the reservoir water edge, lng1 and lng2 are the lower limit and upper limit of the longitude range of the high-precision electronic map, and lat1 and lat2l are the lower limit and upper limit of the latitude range of the high-precision electronic map.

[0074] S5: Using the longitude and latitude coordinates of the pixel points on the reservoir water edge generated in step S4 and the longitude and latitude coordinates of the earthquake epicenter in the earthquake event data obtained in step S1, the longitude and latitude coordinate system two-point distance conversion formula is used to calculate the shortest distance from the earthquake epicenter to the reservoir water edge, complete the conversion of longitude and latitude (unit "°") to distance (unit "km"), and generate a calculation result file containing the shortest distance from the earthquake epicenter to the reservoir water edge (content such as Figure 6 At the same time, a frequency statistics file is generated by setting the shortest distance between the earthquake epicenter and the reservoir water edge (the content is as shown in Figure 7 As shown), the distance conversion formula between two points in the longitude and latitude coordinate system is:

[0075]

[0076] Among them, S is the distance from the epicenter of the earthquake to the corresponding pixel point on the reservoir water edge, (x1, y1) is the longitude and latitude coordinates of the epicenter of the earthquake, (x2, y2) is the longitude and latitude coordinates of the corresponding pixel point on the reservoir water edge, and r is the radius of the earth.

[0077] The "distance calculation result file" is usually set as a txt file, and its content includes number, year, month, day, hour, minute, second, latitude (degrees), longitude (degrees), magnitude, depth, location, and the minimum distance from the epicenter of the earthquake to the reservoir water edge.

[0078] The "frequency statistics file" is usually set as an Excel file of frequency statistics results, which is the frequency statistics result generated based on the results of the "distance calculation result file", and the content includes frequency statistics by year, month, and space interval.

[0079] The “spatial interval” is to set the shortest distance from the epicenter of the earthquake to the reservoir water edge at equidistant intervals.

[0080] S6: Based on the frequency statistics file generated in step S5, a comparison chart of the seismic activity frequency in each range of the monitoring area before and after water storage can be generated (e.g. Figure 8 As shown in the figure, the accurate analysis of the reservoir impact area at different stages after the reservoir is filled with water can be completed.

[0081] This embodiment also provides a system for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir, which implements the above-mentioned measurement method, comprising:

[0082] A data acquisition module, used to acquire earthquake event data in the reservoir monitoring area;

[0083] A map extraction module is used to extract a high-precision electronic map including the reservoir monitoring area from a standard electronic map;

[0084] The feature calibration map module assigns characteristic colors to the reservoir elements in the high-precision electronic map to obtain a characteristic electronic map containing only the characteristic colors;

[0085] A digital map module is used to digitize the characteristic electronic map to obtain the longitude and latitude coordinates of each pixel point of the reservoir water edge line in the characteristic electronic map;

[0086] The distance calculation module is used to determine the shortest distance from the earthquake epicenter to the reservoir water edge based on the earthquake event data and the longitude and latitude coordinates of each pixel point on the reservoir water edge.

[0087] The above functional modules can be implemented using the Python programming language. The development speed of the Python programming language is usually faster than other languages, which is very advantageous for rapid development and iteration. It can realize the functions of reservoir influence area map drawing, graphics processing, distance calculation from the epicenter to the reservoir water edge, and statistical classification mapping.

[0088] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0089] In order to make the description of the present disclosure more detailed and complete, the above description is provided for the implementation and specific embodiments of the present invention; however, this is not the only form of implementing or using the specific embodiments of the present invention. The implementation covers the features of multiple specific embodiments and the method steps and sequences used to construct and operate these specific embodiments. However, other specific embodiments can also be used to achieve the same or equivalent functions and step sequences.

[0090] Those skilled in the art may also understand that the various illustrative logical blocks, units, and steps listed in the embodiments of the present invention may be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly demonstrate the interchangeability of hardware and software, the various illustrative components, units, and steps described above have generally described their functions. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the described functions for each specific application, but such implementation should not be understood as exceeding the scope of protection of the embodiments of the present invention.

[0091] The various illustrative logic blocks or units described in the embodiments of the present invention can be implemented or operated by a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field programmable gate array or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination of the above. The general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0092] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field.

Claims

1. A method for measuring the shortest distance from the epicenter of an earthquake to the edge of a reservoir, characterized in that: Obtain earthquake event data in the reservoir monitoring area; Extracting a high-precision electronic map containing the reservoir monitoring area from a standard electronic map; Assigning characteristic colors to reservoir elements in the high-precision electronic map to obtain a characteristic electronic map containing only the characteristic colors; Digital processing is performed on the characteristic electronic map to obtain the longitude and latitude coordinates of each pixel point of the reservoir water edge line in the characteristic electronic map; The shortest distance from the earthquake epicenter to the reservoir water edge is determined based on the earthquake event data and the longitude and latitude coordinates of each pixel point on the reservoir water edge.

2. The method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir according to claim 1, characterized in that: The type of the standard electronic map is any one of Amap, Tencent Map, and Baidu Map.

3. The method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir according to claim 1, characterized in that: The process of extracting a high-precision electronic map containing the reservoir monitoring area from a standard electronic map is as follows: Determine the type and tile level of standard electronic maps; Calculate the coordinates of the boundary tile map of the reservoir monitoring area according to the latitude and longitude range and tile level of the reservoir monitoring area; Obtaining coordinates of all tile maps and tile maps including the reservoir monitoring area from the standard electronic map according to the coordinates of the boundary tile map; All tile maps are successively spliced ​​based on the principle of tile coordinate proximity to obtain a high-precision electronic map covering the reservoir monitoring area.

4. The method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir according to claim 3, characterized in that: The coordinates of the boundary tile map of the reservoir monitoring area are calculated by the following formula: Among them, (tileX, tileY) is the coordinate of the boundary tile map of the reservoir monitoring area, Level is the tile level, and (pointX, pointY) is the latitude and longitude coordinates of the boundary point of the reservoir monitoring area.

5. The method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir according to claim 1, characterized in that: The process of digitizing the characteristic electronic map is as follows: extracting the reservoir water edge line of the reservoir in the characteristic electronic map, obtaining the pixel coordinates of each pixel point on the reservoir water edge line, and converting the pixel coordinates of each pixel point on the reservoir water edge line into longitude and latitude coordinates through a coordinate conversion formula.

6. The method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir according to claim 5, characterized in that: The coordinate transformation formula is: lng=(pixelX / X)×(lngg2-lng1)+lng1 lat=(pixelY / Y)×(lat2-lat1)+lat1 Among them, (lng, lat) are the longitude and latitude coordinates of the corresponding pixel point on the reservoir water edge; X and Y are the pixel values ​​of the feature electronic map, (pixelX, pixelY) are the pixel coordinates of the corresponding pixel point on the reservoir water edge, lng1 and lng2 are the lower limit and upper limit of the longitude range of the high-precision electronic map, and lat1 and lat2 are the lower limit and upper limit of the latitude range of the high-precision electronic map.

7. The method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir according to claim 1, characterized in that: The distance from the epicenter of the earthquake to the edge of the reservoir water is calculated using the distance calculation formula between two points in the longitude and latitude coordinate system. The calculated distances are compared, and the minimum distance is taken as the shortest distance from the epicenter of the earthquake to the edge of the reservoir water.

8. The method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir according to claim 7, characterized in that: The distance calculation formula between two points in the latitude and longitude coordinate system is: Among them, S is the distance from the epicenter of the earthquake to the corresponding pixel point on the reservoir water edge, (x1, y1) is the longitude and latitude coordinates of the epicenter of the earthquake, (x2, y2) is the longitude and latitude coordinates of the corresponding pixel point on the reservoir water edge, and r is the radius of the earth.

9. The method for measuring the shortest distance from the epicenter of an earthquake to the water edge of a reservoir according to claim 1, characterized in that: After determining the shortest distance from the earthquake epicenter to the reservoir water edge, generate a distance calculation result file based on the earthquake event data; at the same time, set the spatial interval of the shortest distance from the earthquake epicenter to the reservoir water edge to generate a distance frequency statistics file.

10. A system for measuring the shortest distance from the epicenter of an earthquake to the edge of a reservoir, characterized in that: include A data acquisition module, used to acquire earthquake event data in the reservoir monitoring area; A map extraction module is used to extract a high-precision electronic map including the reservoir monitoring area from a standard electronic map; The feature calibration map module assigns characteristic colors to the reservoir elements in the high-precision electronic map to obtain a characteristic electronic map containing only the characteristic colors; A digital map module is used to digitize the characteristic electronic map to obtain the longitude and latitude coordinates of each pixel point of the reservoir water edge line in the characteristic electronic map; The distance calculation module is used to determine the shortest distance from the earthquake epicenter to the reservoir water edge based on the earthquake event data and the longitude and latitude coordinates of each pixel point on the reservoir water edge.

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