A coding method for large-scale regional water resources partitioning

Abstract

The present invention provides a coding method for large-scale regional water resource zoning, which belongs to the field of hydrology and water resource technology. The method includes: obtaining large-scale regional watershed divisions through conventional hydrological analysis methods, identifying and coding the watersheds in the large-scale region based on set watershed identification features, and constructing the form of a combination of feature positioning numbers and the number of watersheds contained therein; further judging each characteristic watershed in the large-scale region through set water resource zoning threshold conditions, and coding them in a hierarchical and block-wise manner according to the specified requirements. Coding principle: the coding increases from the upstream to the downstream of the river; considering the topological relationship, odd and even numbers are used to distinguish tributaries or watershed intervals; when the threshold requirements are not met, if the watersheds are adjacent and the continuous combined area exceeds a certain threshold, the coding is performed sequentially according to the threshold conditions. The present invention solves the problems of non-intuitive coding information for large-scale regions, unclear distinction between tributary watershed intervals, and uncontrollable water resource zoning areas.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrology and water resources, and in particular relates to a coding method for large-scale regional water resource partitioning. Background Art

[0002] Water resource zoning is fundamental data for water resource assessment, planning, utilization, development, protection, and management. Accurate water resource zoning boundaries are crucial for accurate water resource assessment, water cycle simulation, and risk assessment. Systematically coding water resource zoning is a crucial prerequisite for conducting watershed water resource assessments, as well as assessments of main and tributary streams and upstream and downstream streams. Existing coding methods for large-scale regional water resource zoning can lead to various issues, including inconsistent outlet levels, significant disparity in controlled areas among tributaries of the same level, and unclear distinctions between main and tributary streams.

[0003] At this stage, further optimization of the coding and naming rules for large-scale regional water resource zones is likely necessary. This approach should be able to assign unique codes to each river segment, reflect the topological relationships of the river network, facilitate computer automatic calculation and understanding, and possess advantages such as high adjustability of coding parameters, high program coding efficiency, and prominent watershed characteristics. Given that large-scale regions may have multiple outlets and that each river within the region corresponds to a watershed of varying sizes and shapes, a coding method for large-scale regional water resource zones has been developed. Summary of the Invention

[0004] In response to the above-mentioned deficiencies in the prior art, the present invention provides a coding method for large-scale regional water resource zoning, which solves the problems of non-intuitive large-scale regional coding information, unclear distinction between tributary catchment areas, and uncontrollable water resource zoning areas.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] This solution provides a coding method for large-scale regional water resource zoning, including the following steps:

[0007] S1. Divide the large-scale area into watersheds and obtain the watershed identification code in the large-scale area by combining the watershed feature location number and the number of watersheds;

[0008] S2. Based on the threshold conditions and principles for setting water resource zoning, the threshold coding blocks of each basin in the large-scale area are judged and block-by-block hierarchical coding is performed, and the coding of the water resource zoning in the large-scale area is completed by combining it with the basin identification code.

[0009] The beneficial effects of the present invention are as follows: the present invention fully reflects the characteristics of the water resource zoning of the main and tributary rivers based on the threshold zoning and the odd-even number characteristics, and effectively controls the area of the water resource zoning where the tributaries are located; through the information such as the size, location, water system connectivity, river network density, etc. (including but not limited to this), the hydrological characteristics and basin characteristics of the basin in the large-scale area can be fully considered, which has obvious advantages for carrying out basic work such as refined water resource evaluation and basin characteristic evaluation in large-scale areas, and the encoding method is intuitive, which is more conducive to the adjustment and identification of computer encoding parameters.

[0010] Furthermore, the step S1 includes the following steps:

[0011] S101. Preprocess the digital elevation data of the study area using hydrological analysis methods to obtain the corresponding watersheds of multiple river outlets in a large-scale area, and obtain regional elevation files without depressions, regional river flow direction files, regional runoff accumulation files, and watershed division files.

[0012] S102, obtaining identification features of each watershed in the large-scale area through the file obtained in step S101, and combining threshold conditions to determine a feature frame with watershed identification function;

[0013] S103. The file obtained in step S101 is combined with the division method of the watershed in the feature frame to obtain the number of watersheds under different characteristic conditions in the large-scale area, and the numbers are numbered one by one according to the spatial relative position of the water outlet. Combined with the number of the feature frame in step S102, the numbers are combined into the watershed identification code of the large-scale area.

[0014] The beneficial effect of the above further scheme is: the present invention can obtain the characteristic information of each river basin in a large-scale area through conventional hydrological analysis, and further identify the hydrological characteristics of each river basin in the area with the characteristic positioning number. In combination with the number of river basins, the characteristics of each river basin and its sorting within the river basin can be directly displayed according to the code, which is convenient for computer automatic calculation and understanding. The coding method is intuitive, the coding parameters are adjustable, and the program coding efficiency is high.

[0015] Furthermore, step S2 includes the following steps:

[0016] S201. Set m types of threshold conditions for water resource zoning control areas according to demand. Based on the conversion relationship between the threshold and the cumulative flow, divide the regional cumulative flow number file in step S101 into blocks once for each threshold, and obtain n types of cumulative flow number block divisions. The threshold conditions are synchronized with the threshold conditions in step S102.

[0017] S202: Based on the m water resource zoning thresholds in step S201, k coding blocks of corresponding levels are set from left to right. In combination with the n types of confluence accumulation number block division in step S201, the thresholds of the k coding blocks of corresponding levels are encoded according to the encoding principle, wherein the coding blocks are composed of pure numbers;

[0018] S203: Combine the coding block in step S202 with the watershed identification code in step S103 to complete the coding of large-scale regional water resource partitions.

[0019] Furthermore, the encoding construction of the threshold value must meet the following three conditions:

[0020] The coding form under each threshold condition is determined based on the regional runoff accumulation number file, and the water resource division codes increase from small to large;

[0021] The regional flow accumulation file is used to characterize the flow accumulation process. At most, two data are superimposed. The larger direction of the two data is used as the direction of the main river channel, and the direction of the other data is used as the direction of the tributary. Odd and even numbers are used to distinguish tributaries or main river channels.

[0022] When the threshold requirement is not met, if the watersheds are adjacent and the combined area exceeds the threshold, they are coded sequentially according to the threshold conditions.

[0023] The beneficial effect of the above further solution is that the present invention can intuitively analyze whether a water resource zone in a river basin is a tributary or a main river channel based on the coded information, and the location of the zone within the upper-level water resource zone. The area of tributaries within the water resource zone is also controllable. The coding content is intuitive and easy for computers to recognize, and this coding method can easily deduce the upstream and downstream relationships of water resource zones within the river basin. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Flow chart of the method of the present invention.

[0025] Figure 2 This is an example diagram of the coding of the Murray-Darling River and its outlet area in Australia in this embodiment.

[0026] Figure 3 This is an example diagram of coding of some characteristic watersheds in the Murray-Darling River estuary area in this embodiment.

[0027] Figure 4 An example diagram of the coding of the situation where the continuous characteristic watersheds in the study area meet the threshold requirements in this implementation. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0029] Example

[0030] like Figure 1 As shown, the present invention provides a coding method for large-scale regional water resource partitioning, and its implementation method is as follows:

[0031] S1. Divide the large-scale area into watersheds and obtain the watershed identification code in the large-scale area by combining the watershed feature location number and the number of watersheds. The implementation method is as follows:

[0032] S101. Preprocess the digital elevation data of the study area using hydrological analysis methods to obtain the corresponding watersheds of multiple river outlets in a large-scale area, and obtain regional elevation files without depressions, regional river flow direction files, regional runoff accumulation files, and watershed division files.

[0033] S102, obtaining identification features of each watershed in the large-scale area through the file obtained in step S101, and combining threshold conditions to determine a feature frame with watershed identification function;

[0034] S103. The file obtained in step S101 is combined with the division method of the watershed in the feature frame to obtain the number of watersheds under different characteristic conditions in the large-scale area, and the numbers are numbered one by one according to the spatial relative position of the water outlet. Combined with the number of the feature frame in step S102, the numbers are combined into the watershed identification code of the large-scale area.

[0035] In this embodiment, the data of the study area are preprocessed by conventional hydrological analysis methods (filling depressions, flow direction, cumulative runoff, and watershed generation) to obtain the corresponding watersheds of multiple river outlets in a large-scale area. The following files can be obtained: regional elevation files without depressions, regional river flow direction files, regional cumulative runoff files, and watershed division files.

[0036] In this embodiment, three types of features, namely, watershed location, watershed area, and river network density, are selected as the basis for constructing the watershed feature positioning number (watershed features may include single or multiple combinations of watershed location, watershed area, watershed river network density, river network development coefficient, hydrological connectivity, etc., including but not limited to these). Correspondingly, three groups of watershed feature boxes may be set to correspond to the watershed location (which can be obtained through the regional location feature of the watershed division file in S101), watershed area control (i.e., threshold condition, which is expanded in detail in S201), and river network density feature (which can be obtained through the regional confluence cumulative number file in S101). The setting form may be similar to the following, but is not limited thereto;

[0037]

[0038] Note: × represents a certain type of watershed identification feature. There is no restriction on the length and encoding method of the feature box. It is only used as a placeholder in the example.

[0039] In this embodiment, by determining the watershed characteristic conditions in S102 and then combining them with the watershed demarcation file in S101, the number of watersheds in the large-scale area that meet the watershed characteristic conditions can be obtained. These watersheds are numbered sequentially in upstream and downstream order (001, 002, ...). By combining this with the feature location number in S102, the resulting watershed identification code is combined to intuitively identify watershed characteristics and number characteristics. For example, 3A11130 indicates the 130th watershed in this area. If 130 is the largest code in the 3A11 feature area, then there are 130 watersheds in the feature area.

[0040] S2. Based on the threshold conditions and principles for setting water resource zoning, threshold coding blocks are judged for each basin in the large-scale area and block-by-block hierarchical coding is performed. This is combined with the basin identification code to complete the coding of the large-scale regional water resource zoning. The implementation method is as follows:

[0041] S201. Set m types of threshold conditions for water resource zoning control areas according to demand. Based on the conversion relationship between the threshold and the cumulative flow, divide the regional cumulative flow number file in step S101 into blocks once for each threshold, and obtain n types of cumulative flow number block divisions. The threshold conditions are synchronized with the threshold conditions in step S102.

[0042] S202: Based on the m water resource zoning thresholds in step S201, k coding blocks of corresponding levels are set from left to right. In combination with the n types of confluence accumulation number block division in step S201, the thresholds of the k coding blocks of corresponding levels are encoded according to the encoding principle, wherein the coding blocks are composed of pure numbers;

[0043] S203. Combine the coding blocks in step S202 with the watershed identification coding in step S103 to complete the coding of the large-scale regional water resources zoning;

[0044] The coding principle satisfies the following three conditions:

[0045] The coding forms under each threshold condition are judged according to the regional flow accumulation number file, and the water resources zoning codes from small to large increase in sequence;

[0046] The regional flow accumulation number file is used to characterize the process of flow accumulation. At most two data are superimposed, and the direction of the larger of the two data is taken as the direction of the main river channel, and the direction where the other data is located is taken as the tributary direction, and the tributary or the main river channel is distinguished by odd and even numbers;

[0047] When the threshold requirement is not met, if the watersheds are adjacent and the combined area exceeds the threshold, sequential coding is performed according to the threshold condition where they are located.

[0048] In this embodiment, by step S1, the characteristics of each watershed are identified and distinguished. Further, by setting m threshold conditions, combined with the water resources zoning area within each watershed and the regional flow accumulation number file (ACC) in step S101 for judgment (the judgment conditions are A1 ≤ ACC < A2, A2 ≤ ACC < A3,..., A m-2 ≤ ACC < A m-1 , ACC ≥ A m ), to determine the position of each sub-watershed in the large-scale region in the water resources zoning code. The aforementioned threshold codes under the judgment conditions are all 0, where A m represents the largest threshold condition.

[0049] In this embodiment, each watershed can continue to perform water resources zoning according to the set threshold conditions, but the coding size needs to increase sequentially according to the order of each watershed. The aforementioned threshold codes under the same judgment conditions are all 0, and the coding lengths corresponding to each threshold condition can be defined by oneself. When constructing the threshold code, the following 3 principles are mainly followed: (1) The coding forms under each threshold condition are judged according to the regional flow accumulation number file in step S101, and the water resources zoning codes involved from small to large increase in sequence; (2) According to the regional flow accumulation number file in step S101, the tributary with the larger value is taken as the main river channel, and the other one is taken as the tributary, and further the tributary or the catchment area is distinguished by odd and even numbers; (3) When the threshold requirement is not met, if the watersheds are adjacent and the combined area exceeds a certain threshold, sequential coding is performed according to the threshold condition where they are located (if this threshold condition has been coded up to 130, then increase sequentially: 131, 132,...). The first 2 principles are applicable to meeting the m threshold conditions in step S201, while the last principle is mainly applicable to the case of ACC < A1.

[0050] The present invention will be further described below.

[0051] In this example, the Murray-Darling River and its estuaries in Australia, Oceania, are selected as the research area. Figure 2 As shown in the figure, the digital elevation data used was downloaded from the 90-meter SRTM (Shuttle Radar Topography Mission) data provided by NASA. The conventional hydrological analysis process and results will not be repeated here.

[0052] S1: Construct a watershed identification code, which is a combination of the watershed feature location number and its watershed number:

[0053] (1) Basin feature location number. In this embodiment, basin location and basin area are selected as the identification features of the basin (for details, see Figure 2 As shown in the figure), the scope is further referenced to the relevant water conservancy survey report according to the river classification method, and finally 50,000 km 2 ,10,000km 2 ,01,000km 2 ,00100km 2 , 0.005 million km 2 It is the control threshold for water resources zoning in the basin.

[0054] (2) Numbering of river basins: By judging the above river basin characteristic conditions, the number of rivers that meet the characteristics of each river basin is counted. The specific form of expression can be as follows: Figure 2 、 3 As shown. Figure 3 For example, to meet 0.01 thousand km 2 ~01,000km 2 Each basin in the threshold case is numbered sequentially. There are 12 characteristic basins under this feature (located in the Oceania flow, empties into the Indian Ocean, and the Murray Darling River area), and the codes are: 13c4001 to 13c4012;

[0055] S2: Principles to be followed when constructing codes: (1) Codes increase in order from upstream to downstream of the river; (2) Considering the topological relationship, use odd and even numbers to distinguish tributaries or watershed intervals; (3) If the threshold requirement is not met, if the basins are adjacent and the continuous combined area exceeds a certain threshold, the codes are sequentially coded according to the threshold conditions. Figure 2 As an example, the coding blocks under different thresholds are constructed. The coding increases from the upstream to the downstream of the river. The odd and even numbers in each coding block are used to distinguish the tributaries and the catchment areas. The coding of the estuary area increases in sequence. Figure 3 For example, to meet the requirements of 0.01 thousand km 2 ~01,000km 2The watersheds of the threshold case are numbered sequentially. If the watershed can be further partitioned according to the threshold, the numbers are increased in sequence when the previous watershed has the largest code. Figure 4 For example, the combined area of adjacent and continuous regions in principle (3) reaches 0.005km 2 The combined feature basin is sequentially increased according to the maximum number of codes under the threshold.

[0056] The present invention fully reflects the characteristics of water resource zoning of main and tributary rivers based on threshold zoning and odd-even number characteristics, and effectively controls the area of water resource zoning where the tributaries are located; through information such as basin size, location, water system connectivity, and river network density, the hydrological characteristics and basin characteristics of the basin in a large-scale area can be fully considered, which has obvious advantages in carrying out basic work such as refined water resource evaluation and basin characteristic evaluation in a large-scale area. The encoding method is intuitive and is more conducive to the adjustment and recognition of computer codes.

Claims

1. A coding method for large-scale regional water resource partitioning, characterized in that: The following steps are involved: S1. Divide the large-scale area into watersheds and obtain the watershed identification code in the large-scale area by combining the watershed feature location number and the number of watersheds, including the following steps: S101. Preprocess the digital elevation data of the study area using hydrological analysis methods to obtain the corresponding watersheds of multiple river outlets in a large-scale area, and obtain regional elevation files without depressions, regional river flow direction files, regional runoff accumulation files, and watershed division files. S102, obtaining identification features of each watershed in the large-scale area through the file obtained in step S101, and combining threshold conditions to determine a feature frame with watershed identification function; S103. The file obtained in step S101 is combined with the division method of the watershed in the feature frame to obtain the number of watersheds under different characteristic conditions in the large-scale area. The watersheds are numbered one by one according to the spatial relative position of the water outlets, and combined with the number of the feature frame in step S102 to form the watershed identification code of the large-scale area. S2. Based on the threshold conditions and principles for setting water resource zoning, threshold coding blocks are judged for each basin in the large-scale area and block-by-block hierarchical coding is performed. This is combined with the basin identification code to complete the coding of the large-scale regional water resource zoning, including the following steps: S201. Set m types of threshold conditions for water resource zoning control areas according to demand. Based on the conversion relationship between the threshold and the cumulative flow, divide the regional cumulative flow number file in step S101 into blocks once for each threshold, and obtain n types of cumulative flow number block divisions. The threshold conditions are synchronized with the threshold conditions in step S102. S202: Based on the m water resource zoning thresholds in step S201, k coding blocks of corresponding levels are set from left to right. In combination with the n types of confluence accumulation number block division in step S201, the thresholds of the k coding blocks of corresponding levels are encoded according to the encoding principle, wherein the coding blocks are composed of pure numbers; S203: Combine the coding block in step S202 with the watershed identification code in step S103 to complete the coding of large-scale regional water resource partitions.

2. The coding method for large-scale regional water resource partitioning according to claim 1 is characterized in that: The coding principle meets the following three conditions: The coding form under each threshold condition is determined based on the regional runoff accumulation number file, and the water resource division codes increase from small to large; The regional flow accumulation file is used to characterize the flow accumulation process. At most, two data are superimposed. The larger direction of the two data is used as the direction of the main river channel, and the direction of the other data is used as the direction of the tributary. Odd and even numbers are used to distinguish tributaries or main river channels. When the threshold requirement is not met, if the watersheds are adjacent and the combined area exceeds the threshold, they are coded sequentially according to the threshold conditions.

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