CN114385959A - Method and device for dividing sub-basin units in dam-near region and storage medium - Google Patents
Method and device for dividing sub-basin units in dam-near region and storage medium Download PDFInfo
- Publication number
- CN114385959A CN114385959A CN202111470624.6A CN202111470624A CN114385959A CN 114385959 A CN114385959 A CN 114385959A CN 202111470624 A CN202111470624 A CN 202111470624A CN 114385959 A CN114385959 A CN 114385959A
- Authority
- CN
- China
- Prior art keywords
- sub
- basin
- watershed
- dam
- rainstorm
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T17/00—Three dimensional [3D] modelling, e.g. data description of 3D objects
- G06T17/05—Geographic models
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A10/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE at coastal zones; at river basins
- Y02A10/40—Controlling or monitoring, e.g. of flood or hurricane; Forecasting, e.g. risk assessment or mapping
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Software Systems (AREA)
- Mathematical Physics (AREA)
- Data Mining & Analysis (AREA)
- Geometry (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Databases & Information Systems (AREA)
- Computational Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Algebra (AREA)
- Remote Sensing (AREA)
- Computer Graphics (AREA)
- Alarm Systems (AREA)
Abstract
The invention discloses a method, a device and a storage medium for dividing sub-basin units in a dam-approaching region, wherein the method comprises the following steps: generating a dam-near area water system and a watershed based on DEM data; combining the generated dam-near area water system and the generated watershed, and extracting the topography and landform of the dam-near area watershed based on DEM data; drawing a rainstorm central graph by combining DEM data and rainfall data, and performing sub-basin unit division on the basin near the dam region according to the landform and the rainstorm central graph; the method can clearly reflect the production convergence mode of different underlying surfaces of mountainous regions, plains and the like, reflects the influence of a rainstorm center on the production convergence, makes the sub-basin unit division more reasonable, conveniently considers the physical characteristics of the basin production convergence, improves the flood forecasting precision, ensures stable and reliable data sources, has accurate and reasonable calculation results, solves the problem of how to divide the basin in the near-dam region of a wet area, and is favorable for the deep development of the sub-basin division research.
Description
Technical Field
The invention relates to a method and a device for dividing sub-basin units in a dam-approaching area and a storage medium, and belongs to the technical field of hydrology.
Background
The watershed hydrological model simulates a certain flood runoff process generated on a watershed by a certain structure and parameters through generalized description of the hydrological process and calculates flow data at an outlet section, and is an important tool for flood forecasting work at present. With the development of geographic information technology, remote sensing technology and computer science, even in regions without data or with data shortage, the geographic conditions of drainage basins can be obtained through remote sensing images such as a Digital Elevation Model (DEM), land utilization and soil classification maps.
The surface of the drainage area has characteristics such as non-uniformity of rainfall distribution, non-uniformity of properties of the underlying surface, non-uniformity of properties of river network, and the like. To account for these non-uniformities, the computation watershed is often divided into a plurality of unit watersheds, and rainfall-runoff computation is performed separately in each unit watershed. The different number of the blocks in the flow area causes different treatment to the nonuniformity, the different average effects of the relevant influencing factors on the runoff formation process, and the corresponding change of the model parameters.
How to reasonably divide the watershed by using the DEM data and the rainfall data is to consider the influence of the geographic characteristic spatial nonuniformity on the watershed flood simulation to a certain extent, and is also one of key points and difficulties in the watershed flood simulation and forecast trend distribution and refinement process.
When a near dam region watershed blocking method is researched, the first challenge is to determine the number of sub watershed partitions, partition basis and convergence threshold. In the current practical application, the sub-watershed division is mainly performed by an empirical method. This method does not have a strong foundation and thus cannot ensure its rationality.
Aiming at the defects, the problem to be solved by the inventor is how to establish a reasonable sub-basin unit division method and conveniently adopt a hydrological model to forecast the basin flood.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, provides a method, a device and a storage medium for dividing sub-basin units in a dam-close region, has the advantages of stable and reliable data source, high calculation efficiency, objective and reasonable result and the like, and is worthy of popularization.
In order to achieve the purpose, the invention is realized by adopting the following technical scheme:
in a first aspect, the present invention provides a method for dividing sub-basin units in a near dam region, including:
generating a dam-near area water system and a watershed based on DEM data;
combining the generated dam-near area water system and the generated watershed, and extracting the topography and landform of the dam-near area watershed based on DEM data;
drawing a rainstorm center graph by combining DEM data and rainfall data;
and performing sub-basin unit division on the near-dam area basins according to the landform and the rainstorm central diagram.
Further, the dam-near water system and the watershed are generated based on the DEM data, and the method comprises the following steps:
performing swabbing on the watershed based on the digital elevation DEM data of the researched watershed, and performing swabbing calculation by adopting a swabbing function;
extracting the flow direction of the drainage basin, wherein the flow direction judgment adopts the following principle: starting from n being 0, expressing the direction by the power n of 2, expressing the direction by 8 directions of east, southeast, south, southwest, west, northwest, north and northeast by numbers 1, 2, 4, 8, 16, 32, 64 and 128 respectively according to the anticlockwise, calculating the distance weight difference between the central grid and each adjacent grid on a window of 3 multiplied by 3, and determining the direction of the grid with the steepest gradient in the 8 directions as the direction of water flow;
performing convergence accumulation calculation on the watershed based on the water flow direction data;
giving a confluence threshold T, extracting a river channel from the river basin, and if the generated water system is too sparse, changing the threshold calculation by using a threshold calculation formula and then extracting the river channel again;
and extracting watershed of the sub-watershed, and dividing the watershed basic units, wherein the number of the watershed basic units is consistent with that of the extracted riverways.
Further, the combination of the generated dam-near area water system and the generated watershed extracts the landform and the geomorphology of the dam-near area watershed based on the DEM data, and the method comprises the following steps:
extracting basic topographic feature elements of the drainage basin by utilizing a DEM (digital elevation model), wherein the basic topography comprises points, lines and surfaces for controlling topographic distribution features and is used for carrying out topographic division research, and the feature elements comprise gradient slope direction and gradient rate direction change;
calculating the slope and the slope direction after generating the boundary of the research basin, wherein the slope S and the slope direction A of any point on the earth surface are functions of the elevation change rate of the terrain curved surface in the east-west direction, the south-north direction;
obtaining the area between every two contour lines and the length of each contour line according to the DEM of the research basin;
and performing secondary extraction on the slope change rate value on the basis of extraction of the earth surface slope, and calculating to obtain the slope change rate.
Further, the drawing of the rainstorm center graph by combining the DEM data and the rainfall data comprises the following steps:
acquiring coordinates of a hydrological station, a rainfall station and historical rainfall of the hydrological station, wherein the coordinates are used for determining the position of the station in a map, and the historical rainfall is used for subsequent interpolation calculation;
performing space certainty interpolation, and performing interpolation by adopting an inverse distance weighting method;
the rainstorm central graph calculated through interpolation is a square graph covering the whole watershed, the rainstorm central graph is further cut into a proper watershed shape, the amplitude range and the color of the rainfall change are adjusted, and the comparison magnitude of the rainstorm central graph corresponding to flood of different times is ensured to be consistent.
Further, the sub-watershed unit division of the watershed near the dam area according to the landform and the rainstorm central map comprises the following steps:
merging the basin basic units, and preliminarily dividing sub basins;
distinguishing the characteristics of different underlying surfaces in the flow field according to the calculated gradient and slope variability, analyzing the landform and land utilization type characteristics in the flow field, and calculating and solving a land utilization fractal dimension numerical value, wherein when the fractal dimension is small, the influence of human activities is small, and otherwise, the larger the dimension is, the larger the influence of human activities is;
comprehensively using the preliminary division result of the sub-watershed and the storm center graph to determine sub-watershed units;
and (3) extracting each divided sub-basin independently, then extracting the centroid of each sub-basin, and solving the longest flow path length of the sub-basins.
Further, the method also comprises the step of dividing the sub-watersheds at different positions according to regions with large human activity influence, wherein the regions with large human activity influence comprise towns, mountainous regions and plains.
Further, the step of determining the sub-basin unit by comprehensively using the preliminary sub-basin division result and the rainstorm center map comprises the following steps:
setting a threshold value according to rainfall data of each rainfall site by the reverse distance weighting method, and calculating to obtain rainfall distribution on the drainage basin space; the rainfall is represented by color, the darker the color is, the larger the rainfall is represented, the lighter the color is, the smaller the rainfall is represented, and the circle-shaped area with the dark color in the central map of the rainstorm is the central position of the rainstorm;
aiming at a first flood, adjusting the preliminary division result of the sub-river basin units by adopting a visual method based on a rainstorm center graph, and ensuring that a plurality of rainstorm centers of the first flood are all in different sub-river domains;
performing a step of adjusting a sub-watershed unit partition result, wherein the step of adjusting the sub-watershed unit partition result comprises: for the situation that a plurality of rainstorm centers exist in one sub-basin, the sub-basin unit division result is further adjusted by adopting a visual method;
and analyzing the rainstorm center graph of multi-flood in the drainage basin, and repeating the step of adjusting the sub-drainage basin unit division result until no more than one rainstorm center exists in one sub-drainage basin, so as to obtain the sub-drainage basin unit division result.
In a second aspect, the present invention provides a device for dividing sub-basin units in a near dam region, including:
the first extraction unit is used for generating a dam-near area water system and a watershed based on DEM data;
the second extraction unit is used for extracting the landform of the dam-near area drainage basin based on DEM data by combining the generated dam-near area water system and the generated drainage basin;
the storm center drawing unit is used for drawing a storm center drawing by combining DEM data and rainfall data;
and the sub-watershed unit dividing unit is used for dividing the sub-watershed units of the watershed close to the dam region according to the landform and the rainstorm central map.
In a third aspect, the present invention provides a device for dividing sub-basin units in a near-dam region, including a processor and a storage medium;
the storage medium is used for storing instructions;
the processor is configured to operate in accordance with the instructions to perform the steps of the method according to any of the above.
In a fourth aspect, the invention provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of any of the methods described above.
Compared with the prior art, the invention has the following beneficial effects:
the method comprehensively considers the influence of the landform and the rainstorm central position on the division of the sub-basin units of the near-dam area, divides the sub-basin units according to the landform and the rainstorm central area, can clearly reflect the production convergence modes of different underlying surfaces such as mountainous regions, plains and the like, reflects the influence of the rainstorm center on the production convergence, ensures that the sub-basin units are more reasonably divided, is convenient to consider the physical property of the drainage convergence, improves the flood forecasting precision, ensures that the data source is stable and reliable, has accurate and reasonable calculation results, solves the problem of how to divide the near-dam area of the wet area, and is favorable for the deep development of the sub-basin division research.
Drawings
Fig. 1 is a schematic flow chart of a method for dividing sub-basin units in a near-dam region according to an embodiment of the present invention;
FIG. 2 is a data diagram of a watershed DEM provided by an embodiment of the invention;
FIG. 3 is a schematic diagram illustrating flow direction determination principles provided by an embodiment of the present invention;
FIG. 4 is a topographical map of a study area provided by an embodiment of the present invention;
FIG. 5 is a view of a center of a storm in a research area provided by an embodiment of the present invention;
fig. 6 is a diagram illustrating a partition of a drainage sub-drainage unit according to an embodiment of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
Example 1
The embodiment introduces a method for dividing sub-basin units in a near dam region, which includes:
generating a dam-near area water system and a watershed based on DEM data;
combining the generated dam-near area water system and the generated watershed, and extracting the topography and landform of the dam-near area watershed based on DEM data;
drawing a rainstorm center graph by combining DEM data and rainfall data;
and performing sub-basin unit division on the near-dam area basins according to the landform and the rainstorm central diagram.
As shown in fig. 1 to fig. 6, an application process of the method for dividing a sub-watershed cell in a near-dam region provided in this embodiment specifically involves the following steps:
s1, the method for dividing the sub-basin units of the near-dam area comprehensively considering the landform and the rainstorm center is characterized in that in the step 1, the hole filling data, the flow direction data, the confluence accumulated data, the river channel, the watershed and the like of the basin of the near-dam area are extracted, and the method specifically comprises the following steps:
1) digital Elevation (DEM) data (fig. 2) of a basin to be studied is prepared, and since the DEM is a relatively smooth surface simulation, but there are depressed areas in the actual terrain, so that the calculated flow direction does not match the actual flow direction, it is necessary to fill the basin with swabs. And performing filling calculation by adopting a filling function.
2) Extracting the flow direction of the drainage basin, and judging the flow direction by adopting the following principles (figure 3): starting from n-0, the number is represented by the power n of 2, and the numbers 1, 2, 4, 8, 16, 32, 64 and 128 represent the east, southeast, southwest, west, northwest, north and northeast 8 directions respectively in the counterclockwise direction. Namely, on a 3 x 3 window, the distance weight difference between the central grid and each adjacent grid is calculated, and the direction of the grid with the steepest gradient in 8 directions is determined as the direction of the water flow.
3) And performing confluence accumulation calculation on the drainage basin, wherein the confluence accumulation amount is calculated based on the water flow direction data. For each grid, the magnitude of the aggregate represents how many grids upstream of the grid the water flows through the grid, and the greater the aggregate value of the aggregate, the more likely the region will develop surface flow.
4) And (4) giving a convergence threshold value T, extracting the river channel from the river basin, and if the generated water system is too sparse, changing the threshold value calculation by using a threshold value calculation formula and then extracting the river channel again.
The threshold calculation formula is as follows:
in the formula: acckThe cumulative value in the grid cell with the number k is T, the river threshold of the drainage basin is T, and r 1 indicates that the grid cell is a river grid cell, i.e., a river is defined. When r is 0, the grid unit is a sloping field grid unit, and the river channel is not defined.
5) Extracting watershed of the sub-watershed, dividing watershed basic units, wherein the number of the watershed basic units is consistent with the number of extracted riverways, and the denser the water system is extracted, the more finely the sub-watershed is divided, so that the subsequent merging treatment is facilitated.
S2, the method for dividing the sub-basin unit of the near-dam area comprehensively considering the landform and the rainstorm center is characterized in that in the step 2, the generated water system and the generated near-dam area are combined, the landform and the landform of the sub-basin of the near-dam area are extracted based on DEM data, and the method specifically comprises the following steps:
1) the basic topographic feature elements (figure 4) of the drainage basin are extracted by the DEM, mainly points, lines and surfaces for controlling topographic feature distribution features are controlled, and the method can be used for topographic feature division research. The characteristic elements mainly comprise slope direction and slope rate direction change.
2) After the boundary of the research basin is generated, calculation of the slope and the slope direction can be carried out, wherein the slope S and the slope direction A of any point on the earth surface are functions of the high-range change rate of the terrain curved surface in the east-west (Y axis) direction and the south-north (X axis) direction:
in the formula: f. ofx-rate of change of elevation in north-south direction; f. ofy-rate of change of elevation in east-west direction.
3) According to the DEM of the research basin, the area between every two contour lines and the length of each contour line can be obtained. The gradient between the two contour lines is calculated as follows:
in the formula: Δ H-equal distance of height; b-the horizontal distance between two lines of equal height, i.e. b-2 f1/(L0+L1)
On the basis, the gradient between any two contour lines can be obtained, and if n contour lines are shared, the following steps are provided:
the average slope of the watershed is
Comprises the following steps:
in the formula: f-study basin area.
4) The slope variability refers to a slope of Slope (SOA) which is a variability of the slope in the horizontal direction, and is obtained by performing secondary extraction of a slope change rate value on the basis of extraction of the surface slope.
Firstly, calculating an SOA1 with errors; secondly, SOA2 is calculated based on DEM, and the concrete calculation formula of the gradient change rate is as follows:
s3, the method for dividing sub-basin units in the near-dam area comprehensively considering landform and rainstorm centers is characterized in that in the step 3, a rainstorm center graph is drawn by combining DEM data and rainfall data, and the method specifically comprises the following steps:
1) and acquiring coordinates of the hydrological station, the rainfall station and historical rainfall of the hydrological station, wherein the coordinates are used for determining the station position in the map, and the historical rainfall is used for subsequent interpolation calculation.
2) And performing space certainty interpolation, and performing interpolation by adopting an inverse distance weighting method.
Inverse Distance Weighted (IDW) interpolation is based on the principle of close similarity: i.e. two objects are closer together, the more similar their properties, whereas the more distant they are, the less similar. The weighted average is carried out by taking the distance between the interpolation point and the sample point as the weight, and the weight of the sample point closer to the interpolation point is larger. The formula is as follows:
in the formula, Z(s)0) Is s is0The predicted value of (c);
n is the number of sample points around the prediction point to be used in the prediction calculation process;
λifor predicting the weight of each sample point used in the calculation, the value decreases as the distance between the sample point and the predicted point increases;
Z(si) Is at SiThe obtained measurement values.
Determining the weight by a calculation formula;
in the formula: p is an index value,
is a predicted point S0With each known sample point SiThe distance between them.
The weight of the sampling point in the calculation process of the prediction point value is related to the index p; that is, if the distance between the sampling point and the predicted value is decreased, the weight of the influence of the standard sampling point on the predicted point is exponentially increased. In the prediction process, the magnitude of the weight of the contribution of the outlier to the predicted point value is proportional, and the sum of these weight values is 1.
3) The storm rain central map calculated by IDW interpolation is a square map covering the whole watershed, and needs to be further cut into a proper watershed shape, and the amplitude range and the color of the rainfall change are adjusted to ensure that the comparison magnitude of the storm rain central maps (figure 5) corresponding to floods of different times is consistent.
S4, the method for dividing the sub-basin units of the near-dam area comprehensively considering the landform and the rainstorm center is characterized in that in the step 4, the sub-basin units of the near-dam area are divided according to the landform and the rainstorm center, and the method specifically comprises the following steps:
1) the fractional dimension (fractional dimension) method can accurately determine the complexity and the crushing degree of the ground object. The fractal formula is applicable to n-dimensional Euclidean spatial relationship:
when n is 2, it is the fractal formula of two-dimensional Euclidean space, let A (r) and P (r) represent respectivelyrThe area and perimeter of the spot for the measurement scale yields:
P(r)1/D＝kr(1-D)/DA(r)1/2
logarithmic on both sides, i.e.
lg A(r)＝(2/D)lg P(r)+C
D represents a fractal dimension value, A (r) is the area of the land utilization type pattern spot, P (r) is the perimeter of the corresponding land utilization type pattern spot, and C is a undetermined constant.
2) Merging (merge) the basin basic units extracted in the step 1, and preliminarily dividing sub-basins: and (3) distinguishing different underlying surface characteristics such as mountains and plains in the river basin according to the slopes and slope variability calculated in the step (2), wherein the larger the slopes and slope variability is, the steeper the terrain is, namely, the terrain is expressed as a mountain, and then analyzing the terrain and landform and land use type characteristics in the river basin, and then obtaining a land use fractal dimension value according to the formula, wherein the smaller the fractal dimension represents that the influence of human activities is small, and conversely, the larger the fractal dimension represents that the influence of human activities is larger. Human activities also have severe influence on landforms, areas with large influence on human activities can be expressed as towns and distinguished together with different terrains such as mountains and plains, and sub-watersheds are roughly divided at different positions of the watersheds according to the towns, the mountains and the plains.
3) Comprehensively using the primary sub-basin division result based on the landform and the storm-rain central map to determine sub-basin units, the method comprises the following specific steps:
(1) setting a threshold value according to the rainfall data of each rainfall site by the reverse distance weighting method in the step 3, and calculating to obtain rainfall distribution on the drainage basin space; the rainfall is represented by color, the darker the color is, the larger the rainfall is represented, the lighter the color is, the smaller the rainfall is represented, and the circle-shaped area with the dark color in the central map of the rainstorm is the central position of the rainstorm;
(2) aiming at a first flood, adjusting the preliminary division result of the sub-watershed units by adopting a visual method based on a rainstorm center graph to ensure that a plurality of rainstorm centers of the first flood are all in different sub-watersheds;
(3) if the division result of the first flood rainstorm center map in the step (2) is directly adopted, the situation that a plurality of rainstorm centers exist in one sub-watershed may occur for the second flood due to different flood rainstorm center positions of different fields;
(4) for the situation that a plurality of rainstorm centers exist in one sub-basin, the sub-basin unit division result is further adjusted by adopting a visual method;
(5) and (4) analyzing the rainstorm center graph of the multi-flood in the drainage basin, and repeating the step (4) until no more than one rainstorm center exists in one sub-drainage basin, so as to obtain the sub-drainage basin unit division result (figure 6).
4) The sub-basin unit division result obtained by the division in the steps not only can better consider the basin runoff generating space distribution, but also is convenient for quantitatively considering the physical characteristics of confluence: and (3) extracting each divided sub-basin independently, then extracting the centroid of each sub-basin, and solving the longest flow path length of the sub-basins. Peak time delay tpThe time difference between the peak time of the unit line and the centroid time corresponding to the net rain distribution graph is calculated according to the formula:
in the formula, LwThe length of the sub-basin longest river channel is shown, CN is the average curve number in the sub-basin, S is the sub-basin longest river channel gradient, and delta t is the analysis time step length.
Example 2
The present embodiment provides a device for dividing sub-basin unit in a near dam region, including:
the first extraction unit is used for generating a dam-near area water system and a watershed based on DEM data;
the second extraction unit is used for extracting the landform of the dam-near area drainage basin based on DEM data by combining the generated dam-near area water system and the generated drainage basin;
the storm center drawing unit is used for drawing a storm center drawing by combining DEM data and rainfall data;
and the sub-watershed unit dividing unit is used for dividing the sub-watershed units of the watershed close to the dam region according to the landform and the rainstorm central map.
Example 3
The embodiment provides a device for dividing sub-basin units in a dam-approaching region, which comprises a processor and a storage medium;
the storage medium is used for storing instructions;
the processor is configured to operate in accordance with the instructions to perform the steps of the method according to any one of:
generating a dam-near area water system and a watershed based on DEM data;
combining the generated dam-near area water system and the generated watershed, and extracting the topography and landform of the dam-near area watershed based on DEM data;
drawing a rainstorm center graph by combining DEM data and rainfall data;
and performing sub-basin unit division on the near-dam area basins according to the landform and the rainstorm central diagram.
Example 4
The present embodiments provide a computer-readable storage medium, on which a computer program is stored, which when executed by a processor implements the steps of any of the methods:
generating a dam-near area water system and a watershed based on DEM data;
combining the generated dam-near area water system and the generated watershed, and extracting the topography and landform of the dam-near area watershed based on DEM data;
drawing a rainstorm center graph by combining DEM data and rainfall data;
and performing sub-basin unit division on the near-dam area basins according to the landform and the rainstorm central diagram.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A method for dividing sub-basin units in a dam-near area is characterized by comprising the following steps:
generating a dam-near area water system and a watershed based on DEM data;
combining the generated dam-near area water system and the generated watershed, and extracting the topography and landform of the dam-near area watershed based on DEM data;
drawing a rainstorm center graph by combining DEM data and rainfall data;
and performing sub-basin unit division on the near-dam area basins according to the landform and the rainstorm central diagram.
2. The method for dividing sub-basin units in a near dam region according to claim 1, wherein: the dam-near area water system and the watershed are generated based on DEM data, and the method comprises the following steps:
performing swabbing on the watershed based on the digital elevation DEM data of the researched watershed, and performing swabbing calculation by adopting a swabbing function;
extracting the flow direction of the drainage basin, wherein the flow direction judgment adopts the following principle: starting from n being 0, expressing the direction by the power n of 2, expressing the direction by 8 directions of east, southeast, south, southwest, west, northwest, north and northeast by numbers 1, 2, 4, 8, 16, 32, 64 and 128 respectively according to the anticlockwise, calculating the distance weight difference between the central grid and each adjacent grid on a window of 3 multiplied by 3, and determining the direction of the grid with the steepest gradient in the 8 directions as the direction of water flow;
performing convergence accumulation calculation on the watershed based on the water flow direction data;
giving a confluence threshold T, extracting a river channel from the river basin, and if the generated water system is too sparse, changing the threshold calculation by using a threshold calculation formula and then extracting the river channel again;
and extracting watershed of the sub-watershed, and dividing the watershed basic units, wherein the number of the watershed basic units is consistent with that of the extracted riverways.
3. The method for dividing sub-basin units in a near dam region according to claim 1, wherein: the combination of the generated dam-near area water system and the generated watershed extracts the landform and the geomorphology of the dam-near area watershed based on DEM data, and the method comprises the following steps:
extracting basic topographic feature elements of the drainage basin by utilizing a DEM (digital elevation model), wherein the basic topography comprises points, lines and surfaces for controlling topographic distribution features and is used for carrying out topographic division research, and the feature elements comprise gradient slope direction and gradient rate direction change;
calculating the slope and the slope direction after generating the boundary of the research basin, wherein the slope S and the slope direction A of any point on the earth surface are functions of the elevation change rate of the terrain curved surface in the east-west direction, the south-north direction;
obtaining the area between every two contour lines and the length of each contour line according to the DEM of the research basin;
and performing secondary extraction on the slope change rate value on the basis of extraction of the earth surface slope, and calculating to obtain the slope change rate.
4. The method for dividing sub-basin units in a near dam region according to claim 1, wherein: the combination of DEM data and rainfall data draws the storm-rain central map, which comprises the following steps:
acquiring coordinates of a hydrological station, a rainfall station and historical rainfall of the hydrological station, wherein the coordinates are used for determining the position of the station in a map, and the historical rainfall is used for subsequent interpolation calculation;
performing space certainty interpolation, and performing interpolation by adopting an inverse distance weighting method;
the rainstorm central graph calculated through interpolation is a square graph covering the whole watershed, the rainstorm central graph is further cut into a proper watershed shape, the amplitude range and the color of the rainfall change are adjusted, and the comparison magnitude of the rainstorm central graph corresponding to flood of different times is ensured to be consistent.
5. The method for dividing sub-basin units in a near dam region according to claim 1, wherein: the sub-basin unit division of the near-dam area basins according to the landform and the rainstorm central diagram comprises the following steps:
merging the basin basic units, and preliminarily dividing sub basins;
distinguishing the characteristics of different underlying surfaces in the flow field according to the calculated gradient and slope variability, analyzing the landform and land utilization type characteristics in the flow field, and calculating and solving a land utilization fractal dimension numerical value, wherein when the fractal dimension is small, the influence of human activities is small, and otherwise, the larger the dimension is, the larger the influence of human activities is;
comprehensively using the preliminary division result of the sub-watershed and the storm center graph to determine sub-watershed units;
and (3) extracting each divided sub-basin independently, then extracting the centroid of each sub-basin, and solving the longest flow path length of the sub-basins.
6. The method for dividing sub-basin units in a near dam region according to claim 5, wherein: the method further comprises the step of dividing the sub-watersheds into different positions according to regions with large human activity influence, wherein the regions with large human activity influence comprise towns, mountainous regions and plains.
7. The method for dividing sub-basin units in a near dam region according to claim 1, wherein: comprehensively using the preliminary division result of the sub-watershed and the storm center graph to determine sub-watershed units, comprising the following steps:
setting a threshold value according to rainfall data of each rainfall site by the reverse distance weighting method, and calculating to obtain rainfall distribution on the drainage basin space; the rainfall is represented by color, the darker the color is, the larger the rainfall is represented, the lighter the color is, the smaller the rainfall is represented, and the circle-shaped area with the dark color in the central map of the rainstorm is the central position of the rainstorm;
aiming at a first flood, adjusting the preliminary division result of the sub-river basin units by adopting a visual method based on a rainstorm center graph, and ensuring that a plurality of rainstorm centers of the first flood are all in different sub-river domains;
performing a step of adjusting a sub-watershed unit partition result, wherein the step of adjusting the sub-watershed unit partition result comprises: for the situation that a plurality of rainstorm centers exist in one sub-basin, the sub-basin unit division result is further adjusted by adopting a visual method;
and analyzing the rainstorm center graph of multi-flood in the drainage basin, and repeating the step of adjusting the sub-drainage basin unit division result until no more than one rainstorm center exists in one sub-drainage basin, so as to obtain the sub-drainage basin unit division result.
8. A device for dividing sub-basin units in a dam-approaching area is characterized by comprising:
the first extraction unit is used for generating a dam-near area water system and a watershed based on DEM data;
the second extraction unit is used for extracting the landform of the dam-near area drainage basin based on DEM data by combining the generated dam-near area water system and the generated drainage basin;
the storm center drawing unit is used for drawing a storm center drawing by combining DEM data and rainfall data;
and the sub-watershed unit dividing unit is used for dividing the sub-watershed units of the watershed close to the dam region according to the landform and the rainstorm central map.
9. The utility model provides a nearly dam region sub-basin unit divides device which characterized in that: comprising a processor and a storage medium;
the storage medium is used for storing instructions;
the processor is configured to operate in accordance with the instructions to perform the steps of the method according to any one of claims 1 to 7.
10. A computer-readable storage medium having stored thereon a computer program, characterized in that: the program when executed by a processor implements the steps of the method of any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111470624.6A CN114385959A (en) | 2021-12-03 | 2021-12-03 | Method and device for dividing sub-basin units in dam-near region and storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111470624.6A CN114385959A (en) | 2021-12-03 | 2021-12-03 | Method and device for dividing sub-basin units in dam-near region and storage medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114385959A true CN114385959A (en) | 2022-04-22 |
Family
ID=81196201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111470624.6A Pending CN114385959A (en) | 2021-12-03 | 2021-12-03 | Method and device for dividing sub-basin units in dam-near region and storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114385959A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115203984A (en) * | 2022-09-15 | 2022-10-18 | 长江水利委员会水文局 | Flood area composition design method and system based on multi-field secondary flood source characteristics |
-
2021
- 2021-12-03 CN CN202111470624.6A patent/CN114385959A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115203984A (en) * | 2022-09-15 | 2022-10-18 | 长江水利委员会水文局 | Flood area composition design method and system based on multi-field secondary flood source characteristics |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106884405B (en) | Inrush type mountain flood assay method for a kind of Cross Some Region Without Data | |
| Sun et al. | Assessing the effects of land use and topography on soil erosion on the Loess Plateau in China | |
| Gao et al. | Capacity of soil loss control in the Loess Plateau based on soil erosion control degree | |
| Schumann et al. | Application of a geographic information system for conceptual rainfall–runoff modeling | |
| Quinn et al. | The in (a/tan/β) index: How to calculate it and how to use it within the topmodel framework | |
| Kumar et al. | Surface runoff estimation of Sind river basin using integrated SCS-CN and GIS techniques | |
| CN109657841B (en) | Deep extraction method for urban rainstorm waterlogging | |
| Ahmad et al. | Estimation of Clark’s instantaneous unit hydrograph parameters and development of direct surface runoff hydrograph | |
| Ahmad et al. | Estimation of a unique pair of Nash model parameters: an optimization approach | |
| Wu et al. | Simulation of soil loss processes based on rainfall runoff and the time factor of governance in the Jialing River Watershed, China | |
| CN113742910A (en) | Reservoir water inflow early warning and forecasting method and system based on flood forecasting of medium and small watershed | |
| CN112819235B (en) | Method and device for predicting river flow generated by rainfall runoff in area | |
| CN113610264A (en) | Refined power grid typhoon flood disaster prediction model | |
| CN115391712A (en) | Urban flood risk prediction method | |
| CN111062128B (en) | Drainage basin converging simulation estimation method | |
| CN114580910B (en) | Watershed sediment connectivity evaluation method considering road influence | |
| Irvem | Application of GIS to determine storage volume and surface area of reservoirs: the case study of Buyuk Karacay dam | |
| CN114385959A (en) | Method and device for dividing sub-basin units in dam-near region and storage medium | |
| Ammar | Evaluating rainwater harvesting systems in arid and semi-arid regions | |
| Dau et al. | ASSESSMENT OF POTENTIAL IMPACTS OF CLIMATE AND SOCIO-ECONOMIC CHANGES ON FUTURE WATER SECURITY IN THE HIMALAYAS, INDIA. | |
| Al-Hallaq et al. | Determination of mean areal rainfall in the Gaza Strip using geographic information system (GIS) technique | |
| CN112035553B (en) | Hydrological design value calculation method based on space statistics theory | |
| Rumman et al. | Investigation of GIS-based surface hydrological modelling for identifying infiltration zones in an urban watershed | |
| CN112733344B (en) | Method and system for determining artificial drainage basin production flow | |
| Almaaitah et al. | Spatial Distribution of Soil Erosion Risk using RUSLE, RS and GIS Techniques |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |