Method and system for drawing mountainous area submerging range map based on river network section water level

Abstract

The invention relates to the technical field of early warning of mountain torrent disasters, in particular to a method and a system for drawing a mountain area submerging range map based on a river network section water level. For an area between an upstream section and a downstream section and a branch convergence branch point related area, the grid point water level is calculated by adopting a mode of weighting according to river length and constructing virtual section combination weighting, and the influence of the grid point terrain elevation and the levee elevation of both banks of a river is considered; compared with an original method, the submerged range map drawn by the method is finer, the range is not too large, and the method is more practical. According to the method, the water level and the submerging water depth of each grid point in the area are calculated, so that compared with an original method, the submerging range can be obtained, the submerging water depth result of each point in the submerging range can also be obtained, the submerging degrees of different places in the submerging range are depicted more finely, and the work of early warning and disaster reduction of mountain torrent disasters can be better served.

Description

Technical Field

[0001] The present invention relates to the technical field of mountain torrent disaster early warning, and in particular to a method and system for drawing a flood range map of a mountain area based on the water level of a river network section. Background Art

[0002] Due to the large area of ​​flash flood disaster prevention and control and the strong requirements for simulation and early warning timeliness, the two-dimensional hydrodynamic model has the problems of large calculation scale (tens of thousands or even more grids need to be calculated), low calculation efficiency (often taking hours or even longer), and unstable application in areas with large slope gradient changes such as mountainous areas. Therefore, the one-dimensional hydrodynamic model (non-steady flow, steady flow) is still widely used as the main technical means in flash flood disaster simulation and early warning. The one-dimensional hydrodynamic model can simulate the water level, flow rate, and flow velocity process of each section of the mountain river, but it cannot directly obtain the flooding range results of the relatively flat and low-lying areas in the mountainous area. The general practice at present is to connect the left and right bank waterside points of each section in turn according to the topological relationship of the main and tributary rivers and upstream and downstream of the river section, so as to draw a mountain flooding range map.

[0003] This method is easy to implement and simple to operate, but it has the following drawbacks that cannot be ignored:

[0004] The inundation range map of mountainous areas drawn by the current method is basically blocky and angular, which cannot match the undulating characteristics of the regional terrain and is intuitively quite different from the actual situation.

[0005] Based on the method of sequentially connecting waterside points, it is believed that the areas within the line connecting the waterside points of the upstream and downstream sections or the three sections adjacent to the confluence of the tributary are all flooded, and the areas with higher elevations and difficult to be flooded in the area cannot be deducted. This is somewhat different from the actual situation, often resulting in the problem of too large a flash flood disaster warning area;

[0006] The current method does not consider the role of inter-section levees, which may lead to an overestimation of the inundation range;

[0007] The current method can only obtain the flooded range, but cannot obtain the flooded water depth results of each point within the flooded range, and the support capacity for the results of flash flood disaster warning is insufficient. Summary of the invention

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] According to a first aspect of the present invention, the present invention claims a method for drawing a flood range map of a mountain area based on the water level of a river network section, comprising:

[0010] Classifying the rivers in the basin to be drawn, and grouping all the sections of the classified rivers to obtain the river section grouping result of the basin to be drawn;

[0011] According to the river section grouping result, grid point calculation and division are performed on each river section grouping area to obtain the cross-sectional type of each river section grouping;

[0012] Based on the cross-sectional type of each river section group, different strategies are used to calculate the grid water level of each river section group area;

[0013] Obtain the status of river dikes and embankments in each river section grouping area, determine the embankment surrounding area and peripheral area of ​​the river section grouping area, and use the corresponding water depth calculation method to calculate the water depth of the regional grid points;

[0014] Grid points are colored according to the water depth of the regional grid points of the watershed to be drawn, so as to generate a flood range map of the watershed to be drawn.

[0015] Furthermore, the step of performing classification processing on the rivers in the watershed to be mapped further includes:

[0016] Based on the DEM data of the watershed to be drawn, the water system of the watershed to be drawn is extracted, and the Strahler method is used to classify the rivers in the water system of the watershed to be drawn.

[0017] Further, all the sections of the classified rivers are grouped to obtain the river section grouping result of the watershed to be mapped, which also includes:

[0018] The river sections of the classified rivers are dissected, and the river section sections are grouped using the section type grouping method, and the river section grouping calculation sequence is generated;

[0019] Starting from the most downstream section of the highest-level river, determine whether the adjacent upstream element is a section to group the river sections, and so on;

[0020] After the highest level river sections are traversed, grouping will continue from the most downstream section of the next level river that has not been grouped;

[0021] And so on, until all sections on rivers of all levels are grouped.

[0022] Furthermore, the grid point calculation and division of each river section grouping area according to the river section grouping result to obtain the cross-sectional type of each river section grouping also includes:

[0023] Based on the results of river section grouping, each river section grouping area is identified as two-section type for upstream and downstream and three-section type for tributary confluence points;

[0024] The calculation grid points of each group are divided into river section group enclosed areas by using the calculation grid point division method of each group, and the calculation grid points of each river section group are obtained;

[0025] According to the size of the watershed to be mapped and the computational efficiency requirements, the computational grids are resampled to computational grids of coarse spatial resolution.

[0026] Furthermore, the method of dividing the river section group enclosed area by using each group calculation grid point division method to obtain the calculation grid points of each river section group also includes:

[0027] When the river section is grouped into two sections, upstream and downstream, a "quadrilateral" is drawn according to the calculation sequence of the first river section grouping;

[0028] When the river section grouping is a three-section type of tributary confluence point, a "polygon" is drawn according to the calculation order of the second river section grouping or the calculation order of the third river section grouping.

[0029] Furthermore, the method of calculating the grid water level of each river section grouping area using different strategies based on the cross-sectional type of each river section grouping also includes:

[0030] When the cross-sectional type of the river section group is a two-section type, upstream and downstream, the first strategy is used to calculate the grid water level in the river section grouping area;

[0031] When the cross-sectional type of the river section grouping is the three-sectional type of tributary confluence point, the second strategy is used to calculate the grid water level in the river section grouping area.

[0032] Furthermore, when the cross-sectional type of the river section group is a three-sectional type of tributary confluence fork point, the second strategy is used to calculate the grid water level of the river section group area, including:

[0033] Grouping the river sections to generate virtual sections, and calculating the water levels of the virtual sections;

[0034] The grid water level between the original section and the virtual section and the grid water level of the area surrounded by the virtual section are calculated.

[0035] Furthermore, the method of obtaining the state of river dikes and embankments in each river section grouping area, determining the embankment surrounding area and the peripheral area of ​​the river section grouping area, and using the corresponding water depth calculation method to calculate the water depth of the regional grid point also includes:

[0036] According to the calculation order of the river section grouping, determine group by group whether the river ditch in the river section grouping area has a complete embankment along the river;

[0037] If yes, the river section grouping area is divided into a dike surrounding area and a peripheral area; otherwise, the river section grouping area is determined to be a peripheral area;

[0038] The corresponding water depth calculation method is used for the dike enclosed area and the peripheral area to calculate the water depth of each grid point in the section group area.

[0039] Furthermore, the step of coloring the grid points according to the water depth of the regional grid points of the watershed to be drawn to generate a flood range map of the watershed to be drawn further includes:

[0040] All grid points of the watershed to be drawn whose water depth is greater than 0 are connected and then color matching is performed to generate a flood range map of the watershed to be drawn.

[0041] According to a second aspect of the present invention, the present invention claims protection for a system for drawing a flood range map of a mountain area based on the water level of a river network section, comprising:

[0042] one or more processors;

[0043] A memory having one or more programs stored thereon, when the one or more programs are executed by the one or more processors, the one or more processors implement the method for drawing a mountain area flood range map based on the water level of a river network section.

[0044] This application relates to the field of flash flood disaster warning technology, and in particular to a method and system for drawing a flood range map of a mountain area based on the water level of a river network section. Compared with the currently used method of drawing a flood range map by sequentially connecting the water edge points of each section, this method calculates the grid water level by weighting by river length and constructing a virtual section combination weighted method for the area between the upstream and downstream sections and the related areas where the tributaries merge into the branch point, and takes into account the influence of the grid terrain elevation and the elevation of the embankments on both sides of the river. Compared with the original method, the flood range map drawn is more detailed, the range is not too large, and it is more in line with reality. The method of the present invention calculates the water level and flood depth of each grid point in the area. Therefore, compared with the original method, it can not only obtain the flood range, but also the flood depth of each point within the flood range, and has a more detailed description of the flooding degree of different places within the flood range, which can better serve the flash flood disaster warning and disaster reduction work. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A workflow diagram of a method for drawing a mountain area flood range map based on river network section water level as claimed in the first embodiment of the present invention;

[0046] Figure 2 A result map of river network section grouping in the Liyu River Basin according to a method for drawing a mountain flood range map based on the water level of a river network section as claimed in the third embodiment of the present invention;

[0047] Figure 3 Different types of cross-section group enclosed area diagrams of a method for drawing a mountain area flood range map based on the water level of a river network cross-section as claimed in the third embodiment of the present invention;

[0048] Figure 4A virtual cross-section water level result map of a method for drawing a mountain area flood range map based on the river network cross-section water level as claimed in the third embodiment of the present invention;

[0049] Figure 5 A result map of the flood range of the Liyu River Basin, which is a method for drawing a mountain flood range map based on the water level of a river network section, as claimed in the third embodiment of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] The terms "first", "second" and "third" in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" and "third" can explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0052] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0053] In view of the problems in the existing method of drawing the inundation range map of mountainous areas by sequentially connecting the water edge points of the sections in the application of flash flood disaster warning, such as insufficient consideration of regional terrain characteristics, too large a drawn range, failure to consider the water retaining effect of the levees between sections, and failure to obtain the results of the inundation depth, the present invention proposes a method for drawing the inundation range map of mountainous areas based on the water level of the river network section. The method groups the river sections, and for the area between the upstream and downstream sections, the water level of each grid point in the area is calculated by weighting the river length. For the area related to the tributary confluence into the fork, the method of constructing a virtual section is first adopted to ensure that the water levels of the three virtual sections adjacent to the fork are basically equal. For the area between the actual section and the virtual section adjacent to the fork, the water level of each grid point in the area is calculated by the calculation method of the area between the upstream and downstream sections; for the area surrounded by the three adjacent virtual sections, the water level of each grid point in the area is calculated by weighting the shortest distance to each virtual section. For areas with levees, the area enclosed by the levees and the cross-section and the external area are divided; finally, based on the grid point water level results, the grid point elevation and the levee top elevation are superimposed to determine whether each grid point is submerged, and the submerged water depth of each submerged grid point is calculated. The method of the invention can obtain a more accurate mountain area submergence range map than the existing method, and can provide strong theoretical and technical support for mountain torrent disaster simulation and real-time warning.

[0054] According to the first embodiment of the present invention, the present invention claims a method for drawing a mountain flood range map based on the water level of a river network section, referring to Figure 1 ,include:

[0055] Classifying the rivers in the basin to be drawn, and grouping all the sections of the classified rivers to obtain the river section grouping result of the basin to be drawn;

[0056] According to the river section grouping result, grid point calculation and division are performed on each river section grouping area to obtain the cross-sectional type of each river section grouping;

[0057] Based on the cross-sectional type of each river section group, different strategies are used to calculate the grid water level of each river section group area;

[0058] Obtain the status of river dikes and embankments in each river section grouping area, determine the embankment surrounding area and peripheral area of ​​the river section grouping area, and use the corresponding water depth calculation method to calculate the water depth of the regional grid points;

[0059] Grid points are colored according to the water depth of the regional grid points of the watershed to be drawn, so as to generate a flood range map of the watershed to be drawn.

[0060] Furthermore, the step of performing classification processing on the rivers in the watershed to be mapped further includes:

[0061] Based on the DEM data of the watershed to be drawn, the water system of the watershed to be drawn is extracted, and the Strahler method is used to classify the rivers in the water system of the watershed to be drawn.

[0062] Further, all the sections of the classified rivers are grouped to obtain the river section grouping result of the watershed to be mapped, which also includes:

[0063] The river sections of the classified rivers are dissected, and the river section sections are grouped using the section type grouping method, and the river section grouping calculation sequence is generated;

[0064] Starting from the most downstream section of the highest-level river, determine whether the adjacent upstream element is a section to group the river sections, and so on;

[0065] After the highest level river sections are traversed, grouping will continue from the most downstream section of the next level river that has not been grouped;

[0066] And so on, until all sections on rivers of all levels are grouped.

[0067] Among them, in this embodiment, starting from the most downstream section of the highest-level river, the adjacent upstream elements are searched. If it is a section, the downstream section and the upstream section are grouped together. If it is a branch point, the downstream section, the upstream section and the most downstream section of the tributary are grouped together, and so on. After the sections of the highest-level river are traversed, the grouping is continued by the above method starting from the most downstream section of the next-level river that has not been grouped; if there are multiple next-level rivers, they are grouped separately. And so on, until the sections on all levels of rivers are grouped.

[0068] Furthermore, the grid point calculation and division of each river section grouping area according to the river section grouping result to obtain the cross-sectional type of each river section grouping also includes:

[0069] Based on the results of river section grouping, each river section grouping area is identified as two-section type for upstream and downstream and three-section type for tributary confluence points;

[0070] The calculation grid points of each group are divided into river section group enclosed areas by using the calculation grid point division method of each group, and the calculation grid points of each river section group are obtained;

[0071] According to the size of the watershed to be mapped and the computational efficiency requirements, the computational grids are resampled to computational grids of coarse spatial resolution.

[0072] Furthermore, the method of dividing the river section group enclosed area by using each group calculation grid point division method to obtain the calculation grid points of each river section group also includes:

[0073] When the river section is grouped into two sections, upstream and downstream, a quadrilateral is drawn according to the calculation sequence of the first river section grouping;

[0074] When the river section grouping is a three-section type of tributary confluence point, a polygon is drawn according to the calculation sequence of the second river section grouping or the calculation sequence of the third river section grouping.

[0075] In this embodiment, the cross-section group is divided into two cross-section types, upstream and downstream, and three cross-section types at the tributary confluence point. For the cross-section group of two cross-section types, a quadrilateral can be drawn in the order of "right end point of downstream cross-section - right end point of upstream cross-section - left end point of upstream cross-section - left end point of downstream cross-section - right end point of downstream cross-section";

[0076] For the three-section type of the tributary confluence point, if the tributary is a left-bank tributary, a polygon is drawn in the order of "right end point of downstream section - right end point of upstream section - left end point of upstream section - right end point of tributary section - left end point of tributary section - left end point of downstream section - right end point of downstream section";

[0077] If the tributary is a right bank tributary, draw a polygon in the order of "right end point of downstream section - right end point of tributary section - left end point of tributary section - right end point of upstream section - left end point of upstream section - left end point of downstream section - right end point of downstream section".

[0078] Use the quadrilateral or polygon to clip the dem, consider that the original dem has a high spatial resolution (e.g. 1m), set the grid size (e.g. 5m), and use the resampling method to obtain the resampled dem, and the corresponding grid points of this dem are the calculation grid points.

[0079] Furthermore, the method of calculating the grid water level of each river section grouping area using different strategies based on the cross-sectional type of each river section grouping also includes:

[0080] When the cross-sectional type of the river section group is a two-section type, upstream and downstream, the first strategy is used to calculate the grid water level in the river section grouping area;

[0081] When the cross-sectional type of the river section grouping is the three-sectional type of tributary confluence point, the second strategy is used to calculate the grid water level in the river section grouping area.

[0082] Furthermore, when the cross-sectional type of the river section group is a three-sectional type of tributary confluence fork point, the second strategy is used to calculate the grid water level of the river section group area, including:

[0083] Grouping the river sections to generate virtual sections, and calculating the water levels of the virtual sections;

[0084] The grid water level between the original section and the virtual section and the grid water level of the area surrounded by the virtual section are calculated.

[0085] Among them, in this embodiment, when the virtual section of the three-section type section group of the tributary converging into the fork is generated and the water level is calculated, the river channel distance threshold ZLY from the tributary virtual section to the fork is set, and the tributary section is cut according to the distance based on the dem data (the length of the left and right banks of the section is equal to the actual section length of the tributary), as the tributary virtual section ZCX, and the deep elevation (river bottom elevation) of the ZCX section is calculated as ZZX. Starting from the fork, the river bottom elevation is calculated interval by interval to the upstream and downstream of the main stream at the set query interval ΔL. For the upstream of the main stream, if the river bottom elevation UZX satisfies the following formula, the corresponding section of the point upstream of the main stream (the length of the left and right banks of the section is equal to the actual section length of the upstream) is the upstream virtual section UCX:

[0086] ABS(UZX-ZZX)≤E (1)

[0087] Where: ABS() is the absolute value operation, and E is the set allowable elevation error.

[0088] Similarly, for the downstream of the mainstream, if the riverbed elevation DZX satisfies the following formula, the corresponding section at that point downstream of the mainstream (the length of the left and right banks of the section is equal to the length of the actual section downstream) is the downstream virtual section DCX:

[0089] ABS(DZX-ZZX)≤E (2)

[0090] All virtual sections are added to the original section, and the water levels of all sections (including virtual sections) in each time period can be calculated using a one-dimensional hydrodynamic model (steady flow or non-steady flow).

[0091] When calculating the calculation grid water level of the upstream and downstream section type section group, take any grid point G in the calculation grid points of the upstream and downstream section type section group, calculate the shortest distance between grid point G and the two sections (the upstream section is named UC, and the downstream section is named DC) through GIS spatial analysis method, and at the same time obtain the intersection of the distance path and the river channel, named point J. The GIS spatial analysis method is used to obtain the river channel distance UL from point J along the river channel to the upstream section UC and the river channel distance DL from point J along the river channel to the downstream section DC. Combined with the water level UH of the upstream section UC and the water level DH of the downstream section DC, the water level GH at grid point G is calculated using the following formula:

[0092]

[0093] When calculating the calculation grid water level of the three-section type section group where the tributary merges into the branch point, the water level calculation of the calculation grid points between the upstream actual section and the upstream virtual section, the downstream actual section and the downstream virtual section, and the tributary actual section and the tributary virtual section is realized using the formula (3) method.

[0094] For the area surrounded by three virtual sections, the shortest distance UM between any grid point G and the upstream virtual section, the shortest distance DM between any grid point G and the downstream virtual section, and the shortest distance ZM between any grid point G and the tributary virtual section are calculated. Combined with the water levels of each virtual section, the water level GH at the grid point G is calculated using the following formula:

[0095]

[0096] Where: UHX is the water level of the upstream virtual section; DHX is the water level of the downstream virtual section; ZHX is the water level of the tributary virtual section.

[0097] Furthermore, the method of obtaining the state of river dikes and embankments in each river section grouping area, determining the embankment surrounding area and the peripheral area of ​​the river section grouping area, and using the corresponding water depth calculation method to calculate the water depth of the regional grid point also includes:

[0098] According to the calculation order of the river section grouping, determine group by group whether the river ditch in the river section grouping area has a complete embankment along the river;

[0099] If yes, the river section grouping area is divided into a dike surrounding area and a peripheral area; otherwise, the river section grouping area is determined to be a peripheral area;

[0100] The corresponding water depth calculation method is used for the dike enclosed area and the peripheral area to calculate the water depth of each grid point in the section group area.

[0101] Furthermore, the step of coloring the grid points according to the water depth of the regional grid points of the watershed to be drawn to generate the flood range map of the watershed to be drawn further includes:

[0102] All grid points of the watershed to be drawn whose water depth is greater than 0 are connected and then color matching is performed to generate a flood range map of the watershed to be drawn.

[0103] In this embodiment, for the grid points in the peripheral area, the submerged water depth SD is calculated using the following formula according to the elevation GZ of the grid points and the calculated water level value GH:

[0104] If GH>GZ, SD=GH-GZ; otherwise, SD=0(5);

[0105] For the dike enclosed area, the flooding depth SD is calculated using the following formula based on the grid point elevation GZ, the dike top elevation DZ of the nearest dike point to the grid point, and the calculated water level GH:

[0106] If GH>MAX(GZ,DZ), SD=GH-CZ; otherwise, SD=0(6);

[0107] Where: MAX() is the maximum value operation.

[0108] By coloring the grid points with SD greater than 0, a flood range map can be generated.

[0109] According to a second embodiment of the present invention, the present invention claims protection for a system for drawing a flood range map of a mountain area based on a river network section water level, comprising:

[0110] one or more processors;

[0111] A memory having one or more programs stored thereon, when the one or more programs are executed by the one or more processors, the one or more processors implement the method for drawing a mountain area flood range map based on the water level of a river network section.

[0112] According to the third embodiment of the present invention, a method for drawing a mountainous area inundation range map based on the water level of a river network section is requested for protection. This embodiment uses the Liyu River Basin in Huaping County, Lijiang City, Yunnan Province as the research object to conduct hydrological and hydrodynamic simulation and inundation range drawing and analysis.

[0113] The main implementation steps of the present invention are as follows:

[0114] Step 1: Reference Figure 2 Based on the 1m resolution DEM data of the Liyu River Basin, the basin water system was extracted, and the Strahler method was used to classify the rivers in the study basin. The river sections were further dissected, and the section type grouping method was used to group the sections and generate the calculation sequence of the section groups.

[0115] Step 2: Reference Figure 3 Based on the section grouping results, for the two section types of upstream and downstream and the three section types of tributary confluence, the calculation grid division method for each group proposed in the present invention is used to divide the section group enclosed area, and then obtain the 1m resolution calculation grid of each section group. Considering the large scope of the research basin, in order to improve the calculation efficiency, the calculation grid is resampled to 5m resolution to obtain 5m resolution calculation grid of each section group.

[0116] Step 3: Reference Figure 4 , according to the calculation sequence of the section group, determine whether it belongs to the three-section type of the tributary confluence point. If yes, use the virtual section generation and water level calculation method to generate three virtual sections of the upstream and downstream of the main stream and the tributaries, and calculate the water level of the virtual section. Then use the grid water level calculation method of the section group of the upstream and downstream two-section type proposed by the present invention to calculate the grid water level between the upstream and downstream of the main stream and the original section and the virtual section of the tributary. Further, use the grid water level calculation method of the section group of the three-section type of the tributary confluence point proposed by the present invention to calculate the grid water level of the area surrounded by the three virtual sections of the upstream and downstream and the tributaries; if no (that is, it is an upstream and downstream two-section type), use the grid water level calculation method of the section group of the upstream and downstream two-section type to calculate the grid water level between the sections.

[0117] Step 4: According to the calculation sequence of the section groups, determine whether there are complete embankments along the river in the section group area. If yes, divide the embankment surrounding area and the peripheral area. Otherwise, all the section group areas are determined as peripheral areas. The water depth of each grid point in the section group area is calculated using the grid point water depth calculation method of the embankment surrounding area and the peripheral area proposed in the present invention for the embankment surrounding area and the peripheral area.

[0118] Step 5: Reference Figure 5 , connect all grid points with water depth greater than 0 in the Liyu River Basin, and then draw a flood range map in the basin.

[0119] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, systems and methods can be implemented in other ways. For example, the system embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of systems or units, which can be electrical, mechanical or other forms.

[0120] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional units. The above is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly used in other related technical fields, is also included in the patent protection scope of the present invention.

[0121] The specific implementation methods of the invention are described in detail above, but they are only examples, and the invention is not limited to the specific implementation methods described above. For those skilled in the art, any equivalent modification or substitution of the invention is also within the scope of the invention, therefore, the equalization, modification, improvement, etc. made without departing from the spirit and principle of the invention should be included in the scope of the invention.

Claims

1. A method for drawing a mountain area flood range map based on the water level of a river network section, characterized in that: include: Classifying the rivers in the basin to be drawn, and grouping all the sections of the classified rivers to obtain the river section grouping result of the basin to be drawn; According to the river section grouping result, grid point calculation and division are performed on each river section grouping area to obtain the cross-sectional type of each river section grouping; Based on the cross-sectional type of each river section group, different strategies are used to calculate the grid water level of each river section group area; Obtain the status of river dikes and embankments in each river section grouping area, determine the embankment surrounding area and peripheral area of ​​the river section grouping area, and use the corresponding water depth calculation method to calculate the water depth of the regional grid points; Grid points are colored according to the water depth of the regional grid points of the watershed to be drawn, so as to generate a flood range map of the watershed to be drawn.

2. A method for drawing a mountain area flood range map based on river network section water level according to claim 1, characterized in that: The grading process of the rivers in the basin to be mapped also includes: Based on the DEM data of the watershed to be drawn, the water system of the watershed to be drawn is extracted, and the Strahler method is used to classify the rivers in the water system of the watershed to be drawn.

3. The method for drawing a mountain area flood range map based on river network section water level according to claim 1, characterized in that: Grouping all the sections of the classified rivers to obtain the river section grouping results of the watershed to be drawn, further comprising: The river sections of the classified rivers are dissected, and the river section sections are grouped using the section type grouping method, and the river section grouping calculation sequence is generated; Starting from the most downstream section of the highest-level river, determine whether the adjacent upstream element is a section to group the river sections, and so on; After the highest level river sections are traversed, grouping will continue from the most downstream section of the next level river that has not been grouped; And so on, until all sections on rivers of all levels are grouped.

4. The method for drawing a mountain area flood range map based on river network section water level according to claim 1, characterized in that: The method further comprises: performing grid point calculation and division on each river section grouping area according to the river section grouping result to obtain the cross-sectional type of each river section grouping; Based on the results of river section grouping, each river section grouping area is identified as two-section type for upstream and downstream and three-section type for tributary confluence points; The calculation grid points of each group are divided into river section group enclosed areas by using the calculation grid point division method of each group, and the calculation grid points of each river section group are obtained; According to the size of the watershed to be mapped and the computational efficiency requirements, the computational grids are resampled to computational grids of coarse spatial resolution.

5. A method for drawing a mountain area flood range map based on river network section water level according to claim 4, characterized in that: The method of dividing the river section grouping enclosed area by using each group calculation grid point division method to obtain the calculation grid points of each river section grouping also includes: When the river section is grouped into two sections, upstream and downstream, a "quadrilateral" is drawn according to the calculation sequence of the first river section grouping; When the river section grouping is a three-section type of tributary confluence point, a "polygon" is drawn according to the calculation order of the second river section grouping or the calculation order of the third river section grouping.

6. The method for drawing a mountain area flood range map based on the water level of a river network section according to claim 1, characterized in that: The method of calculating the grid water level of each river section grouping area based on the cross-sectional type of each river section grouping by using different strategies also includes: When the cross-sectional type of the river section group is a two-section type, upstream and downstream, the first strategy is used to calculate the grid water level in the river section grouping area; When the cross-sectional type of the river section grouping is the three-sectional type of tributary confluence point, the second strategy is used to calculate the grid water level in the river section grouping area.

7. A method for drawing a mountain area flood range map based on river network section water level according to claim 6, characterized in that: When the cross-sectional type of the river channel cross-sectional group is a three-sectional type of tributary confluence fork point, the second strategy is used to calculate the grid water level of the river channel cross-sectional group area, including: Grouping the river sections to generate virtual sections, and calculating the water levels of the virtual sections; The grid water level between the original section and the virtual section and the grid water level of the area surrounded by the virtual section are calculated.

8. The method for drawing a mountain area flood range map based on river network section water level according to claim 1, characterized in that: The obtaining of the river embankment status in each river section grouping area, determining the embankment surrounding area and the peripheral area of ​​the river section grouping area, and using the corresponding water depth calculation method to calculate the regional grid water depth also includes: According to the calculation order of the river section grouping, determine group by group whether the river ditch in the river section grouping area has a complete embankment along the river; If yes, the river section grouping area is divided into a dike surrounding area and a peripheral area; otherwise, the river section grouping area is determined to be a peripheral area; The corresponding water depth calculation method is used for the dike enclosed area and the peripheral area to calculate the water depth of each grid point in the section group area.

9. The method for drawing a mountain area flood range map based on river network section water level according to claim 1, characterized in that: The step of matching grid points with colors according to the water depth of the regional grid points of the watershed to be drawn to generate a flood range map of the watershed to be drawn further includes: All grid points of the watershed to be drawn whose water depth is greater than 0 are connected and then color matching is performed to generate a flood range map of the watershed to be drawn.

10. A system for drawing a mountain flood range map based on the water level of a river network section, characterized in that: include: one or more processors; A memory having one or more programs stored thereon, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement a method for drawing a mountain area inundation range map based on the water level of a river network section according to any one of claims 1 to 9.

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