Automatic discrimination method for the correlation between water intake users and river cross-sections

Abstract

The present invention provides an automatic discrimination method for the correlation between water intake users and river cross-sections, which relates to the technical field of water resources. The method includes obtaining digital elevation data covering the study area and preprocessing it; calculating the flow direction of grid cells, traversing the grid cells, automatically generating the confluence range of the cross-section, and assigning a unique identifier to generate grid data of the cross-section confluence range; converting the coordinate system of the water intake data to be consistent with the digital elevation data of the study area, assigning a unique identifier to each water intake, converting the water intake user point data into grid cell data with the same resolution as the grid cells, and assigning values to the grid cells according to the water intake ID; and discriminating the spatial correlation between the location of the water intake user and the confluence range of the cross-section according to the generated grid data of the cross-section confluence range and the assignment result. The present invention can batch-judge the water intake users distributed within the confluence range of the cross-section.

Description

Technical Field

[0001] The present invention belongs to the technical field of water conservancy and water resources, and particularly relates to an automatic discrimination method for the association relationship between water intake users and river cross-sections. Background Technique

[0002] With the development of the economic society, the number of water intake users (such as enterprises, agricultural irrigation areas, water plants, etc.) directly taking water from natural water bodies has increased significantly. Under the background of refined water resources management, the management of water intake users has been gradually strengthened. The locations of water intake users in the basin / region are relatively scattered, but their water intake, water use, and drainage processes have a great impact on the runoff of the control cross-sections in the basin / region. Therefore, it is very important to determine the number and water intake of water intake users within the confluence range of the control cross-section when constructing a basin / region water resources allocation model, which is beneficial to improving the accuracy of calculating the cross-section runoff of the model. At the same time, when there is a water shortage or the ecological flow of the cross-section is insufficient, it is necessary to specifically regulate the water intake users associated with the river cross-section.

[0003] Currently, there is no specific method to automatically discriminate the spatial association relationship between water intake users and key river cross-sections. It mainly generates basin partitions based on GIS software (but the cross-section location cannot be considered) or determines the confluence range of river cross-sections according to topographic maps, and determines the confluence range of the cross-section where the water intake user is located based on manual naked-eye observation.

[0004] The method of manual judgment will cause certain errors. For example, it is difficult to discriminate the relationship between water intake users around the watershed or in the plain area and the basin, so that water users in Basin A are judged to be in Basin B. When there are many self-provided water intake users in a certain area or the river water system relationship is complex, the method of manual judgment will increase a large amount of working time. In addition, the existing basin generation methods are basically automatically generated according to DEM data, and the confluence range of the cross-section cannot be separately generated according to the cross-section location. Summary of the Invention

[0005] Aiming at the above deficiencies in the prior art, the present invention provides an automatic discrimination method for the association relationship between water intake users and river cross-sections, which solves the problems of long time consumption, large error, and strong subjectivity in manually judging the relationship between water intake users and cross-sections.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: an automatic discrimination method for the association relationship between water intake users and river cross-sections, including the following steps:

[0007] S1. Obtain digital elevation data covering the study area and preprocess it;

[0008] S2. According to the preprocessed digital elevation data, calculate the flow direction of the grid cells, traverse the grid cells, automatically generate the confluence range of the cross-section, and assign a unique identifier to generate cross-section confluence range grid data;

[0009] S3. Convert the coordinate system of the water intake data to be consistent with the digital elevation data of the study area, assign a unique identifier to each water intake, convert the water user data into raster cell data with the same resolution as the raster cells, and assign values to the raster cells according to the water intake ID;

[0010] S4. According to the generated raster data of the cross-section confluence range and the assignment result of step S3, determine the spatial association relationship between the location of the water user and the cross-section confluence range.

[0011] The beneficial effects of the present invention are as follows: Firstly, based on the digital elevation data and the cross-section location of the study area, the confluence range of the cross-section is generated; Secondly, the water user data is collected, and the coordinate information of the water user is converted into raster data; Finally, the raster data of the cross-section confluence range and the raster data of the water user location are superimposed to identify their spatial association relationship. The present invention realizes the rapid identification of the spatial association relationship between water users and the cross-section confluence range of the basin, provides a technical basis for evaluating the impact of decentralized water users on the cross-section runoff, provides technical support for the construction and parameter calibration of the basin / regional water resources allocation model, and can help with the refined and intelligent management of basin / regional water resources and other work.

[0012] Furthermore, the obtaining of the digital elevation data covering the study area and its preprocessing are specifically as follows:

[0013] According to the longitude and latitude coordinates of the study area boundary, use the digital elevation model to extract the digital elevation data covering the study area;

[0014] Perform filling processing on the extracted digital elevation data to remove outliers and missing values, and complete the preprocessing.

[0015] The beneficial effects of the above further solution are as follows: The present invention corrects the possible problems of outliers and missing values in the original digital elevation data, provides the basic working conditions for the following extraction of the cross-section confluence range, and avoids abnormal results.

[0016] Still further, the specific steps of step S2 are as follows:

[0017] According to the preprocessed digital elevation data, for any central raster, calculate the slopes with the eight adjacent rasters around it respectively;

[0018] Based on the magnitude of the slope, determine the confluence direction of the central raster and perform flow direction coding;

[0019] Construct a two-dimensional raster flow relationship table, and traverse all raster cells in turn. According to the flow direction coding, judge the inflow and outflow relationships of adjacent rasters. Among them, the vertical direction in the two-dimensional raster flow relationship table represents the outflow raster, and the horizontal direction represents the inflow raster;

[0020] Starting from the downstream cross-section, traverse and calculate, search upward according to the two-dimensional flow direction relationship table for grids with hydraulic connections, and for all grids with the same hydraulic connection, it is the confluence range of the cross-section, and assign a unique identifier ID BASIN , generate grid data of the cross-section confluence range. Among them, for cross-sections with upstream and downstream relationships on the main stream, traverse until the cross-section; for tributaries, traverse until there are no inflow-related grids. The value of the generated grid data of the cross-section confluence range is ID BASIN , representing the cross-section confluence range to which the grid belongs.

[0021] Furthermore, the expression of the slope is as follows:

[0022]

[0023] Among them, S i represents the slope, Z c represents the elevation value of the central grid, Z i represents the elevation value of the adjacent grid, d i represents the distance between two grids.

[0024] Furthermore, the expression of the flow direction coding is as follows:

[0025]

[0026] Among them, DIR represents the flow direction coding, and argmax(S i ) represents the number of the surrounding adjacent grid with the largest slope.

[0027] The beneficial effects of the above further solution are: Through specific flow direction calculation and coding rules, the present invention determines the flow direction based on elevation, determines the hydraulic connection between grids, and provides a basis for determining the confluence range of the cross-section.

[0028] Furthermore, the specific step S3 is as follows:

[0029] Convert the coordinate system of the water intake data to be consistent with the digital elevation data of the study area, and assign a unique identifier ID to each water intake INT ;

[0030] Initialize the grid data of the water intake so that its number of rows and columns and grid resolution are consistent with the grid data of the cross-section confluence range. Among them, the latitude value range of the generated grid data is [lat j |j = 1, 2, …, n], and the longitude value range is [lon i |i = 1, 2, …, m], lat j represents the latitude value range of the grid data, lon iIndicates the longitude value range, j represents the grid row index in the latitude direction, ranging from 1 to n, indicating the current row; n represents the total number of grid rows in the latitude direction; i represents the grid column index in the longitude direction, ranging from 1 to m, indicating the current column; m represents the total number of grid columns in the longitude direction;

[0031] Traverse all water intake users, and determine the grid position where the water intake user is located and the corresponding grid data row and column numbers according to the longitude and latitude of the water intake user; if the longitude and latitude of a certain water intake user is (lat 0 , lon 0 ), then the longitude and latitude distance of this water intake user from the grid point is:

[0032] DIS lat = Abs(lat 0 - [lat j | i = 1, 2, …, n])

[0033] DIS lon = Abs(lon 0 - [lon i | i = 1, 2, …, m]

[0034] Then this water intake user is closest to the j 0 th column of the grid and closest to the i 0 th row of the grid. Determine the grid (i 0 , j 0 ) in the grid data as the grid where this water intake user is located. Among them, DIS lat and DIS lon respectively represent the longitude and latitude distances of the water intake user from the grid point, Abs() represents the absolute value function, j 0 represents the Index index value of Min(DIS lat ), and i 0 represents the Index index value of Min(DIS lon );

[0035] Map the unique identifier ID INT of the water intake to the grid cell (i 0 , j 0 ) of the water intake, and assign the value of this grid cell as ID INT Water intake user ID.

[0036] The beneficial effect of the above further solution is: The present invention generates water intake grid data that is consistent with the grid data range of the cross-section confluence range, so as to perform matching calculations on the corresponding grids of the two files in step S4, and assign a unique water intake user ID to each grid to support the calculation in step S4.

[0037] Furthermore, the specific step S4 is:

[0038] Using the following formula, the grid data of the cross-section confluence range and the grid data of the water intake users are superimposed and combined to generate new grid cells. Among them, the value of each pixel in the new grid cell is the combination of the cross-section confluence range ID and the water intake ID:

[0039] R combined (i,j)=(R INT (i,j)<<4)+R BASIN (i,j)

[0040] Wherein, R combined (i,j) represents the combined value of the grid c(i,j), and R BASIN (i,j) represents the grid value corresponding to the i-th row and j-th column in the grid data of the cross-section confluence range, and its value is the unique identifier ID of the corresponding cross-section confluence range BASIN , R INT (i,j) represents the grid value corresponding to the i-th row and j-th column in the grid data of the water intake, and its value is the unique identifier ID of the corresponding water intake INT , R INT (i,j)<<4 means shifting the water intake ID 4 bits to the left;

[0041] Traverse the new grid cells, judge the association relationship between the cross-section confluence range and the water intake user space according to the newly generated pixel value, and generate a data set of the spatial association relationship between the water intake user and the cross-section confluence range based on the judgment result.

[0042] The beneficial effect of the above further solution is that the present invention superimposes and combines the grid data of the cross-section confluence range and the grid data of the water intake, generates new grid cells, and judges the association relationship between the cross-section confluence range and the water intake user space according to the newly generated pixel value, and can automatically generate the spatial association relationship between the water intake user and the cross-section confluence range. Description of the Drawings

[0043] Figure 1 It is the flowchart of the method of the present invention. Detailed Embodiments

[0044] The following describes the detailed embodiments of the present invention to facilitate those skilled in the art to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the detailed embodiments. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present invention are within the scope of protection.

[0045] Embodiment

[0046] As Figure 1As shown in the figure, the present invention provides an automatic discrimination method for the correlation between water intake users and river cross-sections, and the implementation method is as follows:

[0047] S1. Obtain the digital elevation data covering the study area and preprocess it, specifically:

[0048] According to the longitude and latitude coordinates of the study area boundary, use the digital elevation model to extract the digital elevation data covering the study area;

[0049] Perform the filling process for removing outliers and missing values on the extracted digital elevation data to complete the preprocessing.

[0050] In this embodiment, according to the longitude and latitude coordinates of the study area boundary, the elevation data covering the study area is extracted from the digital elevation model (DEM) database and preprocessed, including removing outliers and filling missing data, to avoid errors caused by local "depressions" during the flow direction analysis.

[0051] S2. According to the preprocessed digital elevation data, calculate the flow direction of the grid cells, traverse the grid cells, automatically generate the confluence range of the cross-section, and assign a unique identifier to generate the grid data of the cross-section confluence range, specifically:

[0052] According to the preprocessed digital elevation data, for any central grid, calculate the slopes with the eight adjacent grids around it respectively;

[0053] Based on the magnitude of the slope, determine the confluence direction of the central grid and perform flow direction coding;

[0054] Construct a two-dimensional grid flow relationship table, and traverse all grid cells in turn. According to the flow direction coding, judge the inflow and outflow relationships of adjacent grids. Among them, the vertical direction in the two-dimensional grid flow relationship table represents the outflow grid, and the horizontal direction represents the inflow grid;

[0055] Start traversing and calculating from the downstream cross-section, search upward for the grids with hydraulic connections according to the two-dimensional flow direction relationship table. For all the grids with the same hydraulic connection, it is the confluence range of the cross-section, and assign a unique identifier ID BASIN , generate the grid data of the cross-section confluence range. Among them, for the cross-sections with upstream and downstream relationships on the main stream, traverse until the cross-section. For the tributaries, traverse until the grids with no inflow relationship. The value of the generated cross-section confluence range grid is ID BASIN , representing the cross-section confluence range to which the grid belongs.

[0056] In this embodiment, slope calculation: For the central grid c, calculate the slopes with the eight adjacent grids around it respectively:

[0057]

[0058] In this embodiment, the flow direction is determined. Based on the magnitude of the slope, the flow direction of the central grid c is determined and flow direction encoding is performed:

[0059]

[0060] where DIR represents the flow direction encoding, which corresponds to the surrounding adjacent grid numbers 1, 2, 4, 8, 16, 32, 64, 128 in sequence, and argmax(S i ) represents the surrounding adjacent grid number with the largest slope, S i represents the slope, Z c represents the elevation value of the central grid, Z i represents the elevation value of the adjacent grid, d i represents the distance between two grids.

[0061] In this embodiment, a grid flow direction relationship table is established: a two-dimensional grid flow direction relationship table is established, where the vertical direction represents the outflow grid and the horizontal direction represents the inflow grid; all grid cells are traversed in sequence, and according to the flow direction encoding, the inflow and outflow relationships of adjacent grids are judged. If there is a confluence relationship, it is marked as 1, and if there is no confluence relationship, it is marked as 0.

[0062] In this embodiment, the confluence range of the cross-section is determined: starting from the downstream cross-section, traversing and calculating, relying on the flow direction relationship table to search upward for grids with hydraulic connection. Among them, for cross-sections with upstream and downstream relationships on the main stream, traverse until the cross-section; for tributaries, traverse until there are no grids with inflow relationships. All grids with hydraulic connection in the same cross-section are the confluence range of the cross-section, and a unique ID is assigned, for example, the ID format is "BASIN_" plus four digits (such as BASIN_0001).

[0063] S3. Convert the coordinate system of the water intake data to be consistent with the digital elevation, assign a unique identifier to each water intake, and convert the water user data into grid cell data with the same resolution as the grid cells, and assign values to the grid cells according to the water intake ID. Specifically:

[0064] Convert the coordinate system of the water intake data to be consistent with the digital elevation data of the study area, and assign a unique identifier ID INT ;

[0065] Initialize the water intake grid data so that its number of rows and columns and grid resolution are consistent with the grid data of the cross-section confluence range. Among them, the latitude value range of the generated grid data is [lat j |j = 1, 2,..., n], and the longitude value range is [lon i |i = 1, 2,..., m], lat j represents the latitude value range of the grid data, lon irepresents the longitude value range, j represents the grid row index in the latitude direction, ranging from 1 to n, indicating the current row; n represents the total number of grid rows in the latitude direction; i represents the grid column index in the longitude direction, ranging from 1 to m, indicating the current column; m represents the total number of grid columns in the longitude direction;

[0066] Traverse all water intake users, and determine the grid position where the water intake user is located and the corresponding grid data row and column numbers according to the longitude and latitude of the water intake user; if the longitude and latitude of a certain water intake user is (lat 0 , lon 0 ), then the longitude and latitude distance of this water intake user from the grid point is:

[0067] DIS lat = Abs(lat 0 - [lat j | i = 1, 2, …, n])

[0068] DIS lon = Abs(lon 0 - [lon i | i = 1, 2, …, m]

[0069] Then this water intake user is closest to the j 0 th column of the grid and closest to the i 0 th row of the grid. Determine that the grid (i 0 , j 0 ) in the grid data is the grid where this water intake user is located. Among them, DIS lat and DIS lon respectively represent the longitude and latitude distances of the water intake user from the grid point, Abs() represents the absolute value function, j 0 represents the Index index value of Min(DIS lat ), and i 0 represents the Index index value of Min(DIS lon );

[0070] Map the unique identifier ID INT of the water intake to the grid cell (i 0 , j 0 ) of the water intake, and assign this grid cell the value of ID INT water intake user ID.

[0071] In this embodiment, determine the identification number of the water intake: Determine the basic information such as the name, longitude, and latitude of the water intake, and assign a unique ID to it. The ID format is "INT_" plus four digits (such as INT_0001)

[0072] In this embodiment, it is converted into raster data: Initialize the raster data of the water intake, so that its number of rows and columns and raster resolution are consistent with the raster data of the cross-section confluence range unit. Traverse all water users, map them to the raster cells of the cross-section confluence range according to the row and column numbers where they are located, and assign the water user ID to the combined raster cell. That is, encode the data elements of the water user; generate an empty raster data (with longitude and latitude information), called the water intake raster; according to the position information, traverse and calculate the water intake, and according to the attribute information, match the raster to add data attributes. Among them, the matching process includes: 1. Calculate the spatial distance between the longitude and latitude of the water user and the longitude and latitude of all raster cells; 2. Assign the water intake information to the raster cell with the minimum distance.

[0073] S4. According to the generated raster data of the cross-section confluence range and the assignment result in step S3, determine the spatial association relationship between the water user location and the cross-section confluence range. The implementation method is as follows:

[0074] Using the following formula, superimpose and combine the raster data of the cross-section confluence range and the raster data of the water intake to generate new raster cells. Among them, each pixel value in the new raster cell is a combination of the cross-section confluence range ID and the water intake ID:

[0075] R combined (i,j)=(R INT (i,j)<<4)+R BASIN (i,j)

[0076] Among them, R combined (i,j) represents the combined value of the raster c(i,j), and R BASIN (i,j) represents the raster value corresponding to the i-th row and j-th column in the raster data of the cross-section confluence range, and its value is the unique identifier ID of the corresponding cross-section confluence range BASIN , R INT (i,j) represents the raster value corresponding to the i-th row and j-th column in the raster data of the water intake, and its value is the unique identifier ID of the corresponding water intake INT , R INT (i,j)<<4 means shifting the water intake ID 4 bits to the left;

[0077] Traverse the new raster cells, judge the association relationship between the water user and the cross-section confluence range based on the newly generated pixel values, and generate a data set of the spatial association relationship between the water user and the cross-section confluence range based on the judgment result.

[0078] In this embodiment, the superposition of the water user and the cross-section confluence range: Superimpose and combine the raster data of the cross-section confluence range unit and the raster data of the water user by bitwise operation to generate a new raster data, where each pixel value is a combination of the cross-section confluence range ID and the water intake ID.

[0079] In this embodiment, the newly generated grid cells are traversed, and the spatial correlation relationship between the section confluence range and the water intake users is judged according to the newly generated pixel values. For example, the pixel value 00010010 means that the water intake 0010 is located inside the confluence range of section 0001.

[0080] In this embodiment, a spatial correlation relationship dataset between water intake users and section confluence ranges is generated, including the corresponding relationship between water intake IDs and section IDs, water intake information, section information, etc.

[0081] In summary, the present invention realizes the rapid identification of the spatial correlation relationship between water intake users and the section confluence range of the basin, provides a technical basis for evaluating the impact of decentralized water intake users on the section runoff, provides technical support for the construction and parameter calibration of the water resources allocation model in the basin / region, and can help with the refined and intelligent management of water resources in the basin / region, etc.

Claims

1. A method for automatically determining the relationship between water users and river sections, characterized in that: The following steps are involved: S1, obtain digital elevation data covering the study area and preprocess it; S2, according to the pre-processed digital elevation data, the flow direction of the grid unit is calculated and then encoded, and the grid unit is traversed to automatically generate the confluence range of the section, and a unique identifier is assigned to generate the confluence range grid data of the section; S3, convert the coordinate system of the water intake data to be consistent with the coordinate system of the digital elevation data of the study area, assign a unique identifier to each water intake, convert the water intake data to grid cell data with the same resolution as the grid cell, and assign values ​​to the grid cells according to the water intake ID; S4, according to the generated cross-section confluence range grid data and the assignment result of step S3, the spatial correlation relationship between the water user location and the cross-section confluence range is determined; Step S4 includes: The following formula is used to overlay and combine the cross-section confluence range grid data and the water intake user grid data to generate a new grid unit, where each pixel value in the new grid unit is a combination of the cross-section confluence range ID and the water intake ID: R combined (i,j)=(R INT (i,j)<<4)+R BASIN (i,j) Among them, R combined (i,j) represents the combined value of grid c(i,j), R BASIN (i,j) represents the grid value corresponding to the i-th row and j-th column in the cross-section confluence range grid data, and its value is the unique identifier ID of the corresponding cross-section confluence range BASIN , R INT (i,j) represents the grid value corresponding to the i-th row and j-th column in the water intake grid data, and its value is the unique identifier ID of the corresponding water intake. INT , R INT (i, j)<<4 means shifting the water intake ID left by 4 bits; The expression of the flow direction coding is as follows: , where DIR represents the flow direction encoding, argmax(S i ) represents the number of the adjacent grid with the largest slope, S i Indicates slope.

2. The method for automatically determining the relationship between water users and river sections according to claim 1, characterized in that: The digital elevation data covering the study area is obtained and preprocessed, which is specifically as follows: According to the longitude and latitude coordinates of the study area boundary, the digital elevation model is used to extract the digital elevation data covering the study area; The extracted digital elevation data is preprocessed by removing outliers and filling missing values.

3. The method for automatically determining the relationship between water users and river sections according to claim 1, characterized in that: The step S2 is specifically as follows: According to the pre-processed digital elevation data, for any central grid, the slopes of the eight adjacent grids are calculated respectively; Based on the slope, the convergence direction of the central grid is determined and the flow direction is coded; Construct a two-dimensional relationship table of grid flow direction, and traverse all grid cells in turn, and determine the inflow and outflow relationship of adjacent grids according to the flow direction code. In the two-dimensional relationship table of grid flow direction, the vertical direction represents the outflow grid, and the horizontal direction represents the inflow grid; The calculation starts from the downstream section, searches upward for grids with hydraulic connections based on the two-dimensional relationship table of flow direction, takes all grids with hydraulic connections as the confluence range of the section, and assigns a unique identifier ID to the confluence range of the section. BASIN After that, the section confluence range raster data is generated.

4. The method for automatically determining the relationship between water users and river sections according to claim 3, characterized in that: The expression of the slope is as follows: Among them, S i Indicates the slope, Z c Indicates the elevation value of the center grid, Z i Represents the elevation value of the adjacent grid, d i Represents the distance between two grids.

5. The method for automatically determining the relationship between water users and river sections according to claim 1, characterized in that: The step S3 is specifically as follows: The coordinate system of the water intake data is converted to the coordinate system of the digital elevation data of the study area, and a unique identifier ID is assigned to each water intake. INT ; Initialize the water intake grid data so that its number of rows and columns and grid resolution are consistent with the cross-section confluence range grid data. The latitude range of the generated grid data is [lat i |i=1,2,…,n], the longitude value range is [lon j |j=1,2,…,m],lat i Indicates the latitude range of the raster data, lon j represents the range of longitude values, n represents the total number of grid rows in the latitude direction; i represents the i-th row of grid data, j represents the j-th column of grid data, and m represents the total number of grid columns in the longitude direction; Traverse all water users, and determine the grid position of the water user and the corresponding grid data row and column number according to the longitude and latitude of the water user; if the longitude and latitude of a water user is (lat0, lon0), the longitude and latitude distance of the water user from the grid point is: DIS lat =Abs(lat0-[lat j |i=1,2,…,n]) DIS lon =Abs(lon0-[lon i |i=1,2,…,m] Among them, DIS lat and DIS lon They represent the latitude and longitude distances of the water users from the grid points, respectively, and Abs() represents the absolute value function; The unique identifier of the water intake ID INT Mapped to the grid cell (i0, j0) of the water intake, where the grid cell (i0, j0) is assigned ID INT .

6. The method for automatically determining the relationship between water users and river sections according to claim 1, characterized in that: The step S4 further comprises: The new grid cells are traversed, and the spatial correlation between the section runoff range and the water users is determined based on the newly generated pixel values. Based on the determination results, a data set of the spatial correlation between the water users and the section runoff range is generated.

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