Sorting method and current spatial distribution-based rainstorm displacement method

Abstract

The invention relates to a rainstorm displacement method based on a sorting method and current spatial distribution, and the method comprises the steps: sorting the rainfall of different rainfall stations in a target region and a rainstorm displacement region in a rainstorm displacement process; and then corresponding displacement is carried out according to the rainfall capacity of each rainfall station in the rainstorm displacement area and the target area, so that the current spatial distribution characteristics of the target area can be effectively maintained, the rationality of rainstorm displacement is improved, the accuracy of rainstorm forecast in the target area is improved, and flood prevention plans and measures can be practically made.

Description

Technical Field

[0001] The invention relates to the technical field of hydrological forecasting, and in particular to a rainstorm displacement method based on a sorting method and current spatial distribution. Background Art

[0002] Under the background of the intensifying climate change, the frequency and intensity of extreme precipitation events are gradually increasing, and flood disasters are becoming more and more serious, which brings serious risks and challenges to people's production and life and the ecological environment. With the change of climate patterns, extreme precipitation events may become more frequent and violent, posing a severe test to social stability and economic development. In order to effectively reduce the losses that may be caused by extreme precipitation events, it is usually necessary for management departments to take active preventive measures and formulate comprehensive plans and emergency measures in advance. At present, the use of the rainstorm displacement method, that is, considering the similarity of meteorological, geographical and topographic conditions, the measured rainstorm data in the area where extreme precipitation has occurred is transferred to the target area, and the maximum possible rainfall in the target area is obtained to formulate corresponding plans. It has become a relatively effective preventive measure. However, due to the differences in water vapor distribution characteristics between different basins and the incomplete geographical and topographic data in many areas, it is not reasonable to simply transplant rainfall data from other areas to the target basin. It is impossible to shift the rainfall values ​​while maintaining the current spatial distribution characteristics of the target area, and the rationality of the rainstorm displacement cannot be guaranteed, resulting in low accuracy of rainstorm forecasts. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a rainstorm displacement method based on a sorting method and current spatial distribution, which can improve the accuracy of rainstorm displacement and thus improve the accuracy of rainstorm forecast.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: a rainstorm displacement method based on sorting method and current spatial distribution, comprising:

[0005] S1, collect rainfall data in the target area and determine the duration T of the rainstorm to be displaced in the target area, where T is a positive number;

[0006] S2, select a rainstorm displacement area and obtain typical rainstorms in the rainstorm displacement area;

[0007] S3, identifying the rainstorm center of the rainstorm to be relocated in the target area and sorting the rain stations in the target area according to the rainfall amounts of the rain stations in the target area;

[0008] S4, identifying typical rainstorm centers in the rainstorm relocation area and sorting the rainstorm relocation area raingauge stations according to the rainfall of the target area raingauge stations;

[0009] S5, shifting the corresponding rainstorm sequence of the rain gauge stations sorted according to the rainfall amount in the rainstorm shifting area to the rain gauge stations with corresponding sequence numbers in the target area;

[0010] S6, calculating the cumulative rainfall in the target area according to the rainstorm sequence transferred from each rain gauge station in the target area.

[0011] Furthermore, the rainstorm displacement area selected in step 2 includes rainstorms that occur at least once in a hundred years and have rainfall process data records and the duration of the rainstorm is greater than or equal to T.

[0012] Furthermore, the typical rainstorm is a corresponding rainstorm with rainfall process data and the largest cumulative rainfall in the rainstorm displacement area.

[0013] Furthermore, the method for obtaining the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced in step S5 is as follows: determine whether the duration of the typical rainstorm is equal to T. If so, the rainstorm sequence of each raingauge corresponding to the typical rainstorm in the rainstorm displacement area is the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced; if not, obtain the time period T1 corresponding to the duration T and the maximum accumulated rainfall in the typical rainstorm sequence, and the rainstorm sequence of each raingauge in the rainstorm displacement area in the time period T1 is used as the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced.

[0014] Furthermore, in step 3, the rainstorm center of the rainstorm to be displaced in the target area is identified and the rain stations in the target area are sorted according to the rainfall of the rain stations in the target area. Specifically, the cumulative rainfall of each rain station in the target area for a period of time T is calculated, and the calculated cumulative rainfall of each rain station is sorted. The cumulative rainfall of the rain stations in the target area is recorded as P s,i , where i represents the number of the rainfall station in the target area, i is a natural number greater than or equal to 1, and the smaller i is, the higher the corresponding P s,i The larger the value.

[0015] Further, the step S4 of identifying typical rainstorm centers in the rainstorm relocation area and sorting the rainstorm relocation area raingauges according to the rainfall of the target area raingauges specifically includes: calculating the cumulative rainfall of each raingauge in the rainstorm relocation area for a period of time T, and sorting the calculated cumulative rainfall of each raingauge, and the cumulative rainfall of the rainstorm relocation area raingauge is recorded as P x,j , where j represents the number of the rain gauge station in the rainstorm relocation area, j is a natural number greater than or equal to 1, and the smaller j is, the corresponding P x,j The larger the value.

[0016] Furthermore, after executing step S2, the method also includes the step of equal-step-length reorganization of the rainstorm events to be relocated in the target area and the typical rainstorm sequences in the rainstorm relocation area.

[0017] Furthermore, the equal-step reorganization specifically includes reorganizing the rainfall sequence into a rainfall amount sequence with a step size of 1 hour.

[0018] Furthermore, the equal-step reorganization is specifically performed using an interpolation method.

[0019] Furthermore, the calculation of the cumulative rainfall in the target area in S6 is specifically performed using the Thiessen polygon method.

[0020] Compared with the prior art, the advantages of the present invention are: in the process of heavy rain displacement by using the method of the present invention, by sorting the accumulated rainfall of different rain gauges in the target area and the heavy rain displacement area, and then performing corresponding displacement, the current spatial distribution characteristics of the target area can be effectively maintained, and the rationality of heavy rain displacement can be improved, thereby improving the accuracy of heavy rain forecast in the target area, so as to effectively prepare flood prevention plans and measures.

[0021] Instruction Manual

[0022] Figure 1 This is a schematic diagram of heavy rain displacement.

[0023] Figure 2 This is a schematic diagram of the isohyetal lines before the B1 rainstorm in the B basin of a certain city was relocated.

[0024] Figure 3 This is a schematic diagram of isohyetal lines after the B1 rainstorm in the B basin of a certain city was relocated.

[0025] Figure 4 This is a schematic diagram of isohyetal lines before the B2 rainstorm in basin B of a certain city was relocated.

[0026] Figure 5 This is a schematic diagram of isohyetal lines after the B2 rainstorm was relocated in the B basin of a certain city.

[0027] Figure 6 This is a schematic diagram of isohyetal lines before the B3 rainstorm in the B basin of a certain city was relocated.

[0028] Figure 7 This is a schematic diagram of the isohyetal lines after the B3 rainstorm in the B basin of a certain city was relocated. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the embodiments of the drawings, examples of which are shown in the drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0030] In the description of the present application, it should be noted that for directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating directions and positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific protection scope of the present application. The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0031] The present invention relates to a rainstorm displacement method based on a sorting method and current spatial distribution, the method comprising the following steps:

[0032] S1, collect rainfall data in the target area and determine the duration T of the rainstorm to be displaced in the target area, where T is a positive number;

[0033] S2, select a rainstorm displacement area and obtain typical rainstorms in the rainstorm displacement area;

[0034] S3, identifying the rainstorm center of the rainstorm to be relocated in the target area and sorting the rain stations in the target area according to the rainfall amounts of the rain stations in the target area;

[0035] S4, identifying typical rainstorm centers in the rainstorm relocation area and sorting the rainstorm relocation area raingauge stations according to the rainfall of the target area raingauge stations;

[0036] S5, shifting the corresponding rainstorm sequence of the rain gauge stations sorted according to the rainfall amount in the rainstorm shifting area to the rain gauge stations with corresponding sequence numbers in the target area;

[0037] S6, calculating the cumulative rainfall in the target area according to the rainstorm sequence transferred from each rain gauge station in the target area.

[0038] In this embodiment, the rainstorm displacement area selected in step 2 includes rainstorms with rainfall process data records of at least once in a hundred years and a duration of rainstorms greater than or equal to T. Generally, areas with rainstorms once in five hundred years or once in a thousand years can be selected as rainstorm displacement areas. A typical rainstorm is a corresponding rainstorm with rainfall process data and the largest cumulative rainfall in the rainstorm displacement area.

[0039] In this embodiment, the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced in step S5 is obtained as follows: determine whether the duration of the typical rainstorm is equal to T. If so, the rainstorm sequence of each raingauge corresponding to the typical rainstorm in the rainstorm displacement area is the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced. If not, obtain the time period T1 corresponding to the duration of T and the maximum accumulated rainfall in the typical rainstorm sequence, and the rainstorm sequence of each raingauge in the rainstorm displacement area in the time period T1 is used as the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced. That is, when executing this step, the duration of the typical rainstorm in the rainstorm displacement area can be processed to make it the same as the duration of the target area, and then the rainfall sequence of the corresponding time period when the duration is T and the accumulated rainfall is the maximum is selected as the rainfall sequence to be displaced, and the corresponding rainstorm of each raingauge in the rainstorm displacement area is the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced.

[0040] Of course, in order to facilitate subsequent calculations, the data step size of the typical rainstorm sequence in the rainstorm displacement area can also be processed to be consistent with that of the target area. In this embodiment, the data step size of the rainstorm sequence in the target area is 1 hour, and correspondingly, the data of the typical rainstorm sequence is also processed to be 1 hour. When the rainstorm sequence is reorganized with equal step size, an interpolation method such as linear interpolation can be used.

[0041] In this embodiment, in step 3, the rainstorm center of the rainstorm to be displaced in the target area is identified and the rain stations in the target area are sorted according to the rainfall of the rain stations in the target area. Specifically, the cumulative rainfall of each rain station in the target area for a period of time T is calculated, and the calculated cumulative rainfall of each rain station is sorted. In practice, the bubbling method and other methods can be used for sorting. The cumulative rainfall of the rain station is recorded as P s,i , where i represents the number of the rainfall station in the target area, i is a natural number greater than or equal to 1, and the smaller i is, the higher the corresponding P s,i The larger the value, the more rain gauges in the target area are ranked from large to small according to the cumulative flow. s,1 , P s,2 , P s,3 ….

[0042] In this embodiment, the step S4 of identifying the typical rainstorm center in the rainstorm relocation area and sorting the rainstorm relocation area rainstorm stations according to the rainfall of the target area raingauge station specifically includes: calculating the cumulative rainfall of each raingauge station in the rainstorm relocation area for a period of time T, and sorting the calculated cumulative rainfall of each raingauge station, and the cumulative rainfall of the raingauge station is recorded as P x,j , where j represents the number of the rain gauge station in the rainstorm relocation area, j is a natural number greater than or equal to 1, and the smaller j is, the corresponding P x,j The larger the value, the higher the rainfall station in the rainstorm relocation area is. x,1 , P x,2, P x,3 ….

[0043] To further illustrate the rainstorm displacement process, the target area and the rainstorm displacement area are identified, and the rain gauges are sorted according to the cumulative rainfall. The following sorting table can be obtained:

[0044] Table 1 Ranking of rainfall stations in target area and rainstorm relocation area

[0045]

[0046]

[0047] The rainstorm sequence of the rain gauge station in the rainstorm relocation area is relocated to the stations with corresponding serial numbers in the target area, as shown in the following table:

[0048] Table 2. Precipitation statistics of each rainfall station in the target area after relocation

[0049] Serial number Precipitation at each rain gauge in the target area Target area rainfall station number i 1 <![CDATA[P x，1 ]]> <![CDATA[S1]]> 2 <![CDATA[P x，2 ]]> <![CDATA[S2]]> 3 <![CDATA[P x，3 ]]> <![CDATA[S3]]> 4 <![CDATA[P x，4 ]]> <![CDATA[S4]]> 5 <![CDATA[P x，5 ]]> <![CDATA[S5]]> … … …

[0050] Attached Figure 1 The rainstorm displacement process is shown in the figure. Figure 1 Among them, X1, X2, X3, X4, and X5 represent rain stations whose rainfall in the rainstorm relocation area is sorted from large to small, and S1, S2, S3, S4, and S5 represent rain stations whose rainfall in the target area is sorted from large to small. During the relocation process, the rainfall sequence of the rainstorm relocation area's largest rainfall station X1 is relocated to the rainstorm station S1 with the largest rainfall in the target area, and the rainfall sequence of the rainstorm relocation area's rainstorm station X2 is relocated to the rainstorm station S2 in the target area, and so on, thereby completing the rainstorm relocation and then calculating the rainfall in the target area.

[0051] In this embodiment, the Thiessen polygon method in the GIS software analysis tool can be used to calculate the weight table of rain stations in the target area, and then the cumulative rainfall in the target area after the rainstorm is moved is calculated. Of course, other methods can also be used for calculation as needed.

[0052] In order to further illustrate the method of the present invention, a specific example is analyzed below, with the A basin in a city as the relocation area and the B basin as the target area.

[0053] The city's basin has experienced many floods and rainstorms, and the total amount of rainstorms is large, the duration is long, the range is wide, and the extremes are strong, which can be used as a typical rainstorm area; the center of the rainstorm process continues to be maintained in Basin A, and the rainfall process in this basin is selected for rainstorm transplantation. Collect and compile rainfall data of three typical events in Basin B, and compile them into three rainfall sequences with a step length of 1 hour.

[0054] The three largest rainstorms in the rainfall sequence of the past 10 years in Basin A were selected as typical rainstorms, and they were compiled into a rainfall sequence with a step length of 1 hour. In the rainfall sequences of Basin A and Basin B, the rain stations with the largest rainfall in different sessions were identified as the rainstorm centers, and each rain station was sorted according to the rainfall size, and the corresponding rain stations were recorded. The rainfall sequences of each rain station in the three typical rainstorms in Basin A were respectively moved to the three rainstorm scenes in Basin B. For example, the three typical rainstorms in the A basin are A1, A2, and A3, and the three rainstorms in the B basin are B1, B2, and B3. For the A1 rainstorm, calculate the cumulative rainfall of each rain gauge in the A basin, and then sort the rain gauges according to the cumulative rainfall to identify the rainfall center. For the B1 rainstorm, calculate the cumulative rainfall of each rain gauge in the B basin, and then sort the rain gauges according to the cumulative rainfall to identify the rainfall center. Then, shift the rainfall sequence corresponding to the rain gauges in the A basin whose cumulative rainfall is sorted from large to small to the rain gauges in the B basin whose cumulative rainfall is sorted from large to small. Similarly, shift rain gauges A2 and B2 accordingly, and shift rain gauges A3 and B3 accordingly. Finally, use the Thiessen polygon method in the GIS software analysis tool to calculate the weight table of rain gauges, and calculate the cumulative rainfall of the three rain gauges in the target area, i.e., the B basin, before and after the rain gauge shift. Attachment Figures 2 to 7 The diagram shows the isohyets before and after the relocation of three rainstorms in Basin B.

[0055] The three rainstorms selected in the target area of ​​this example, i.e., area B, lasted for 16 hours, 53 hours, and 83 hours respectively. Figure 2 and Figure 3 The isohyet diagrams before and after the B1 rainstorm in the target area were moved. It can be seen that the cumulative rainfall decreases from southeast to northwest. Figure 4 and Figure 5 The isohyet diagrams before and after the relocation of the B2 rainstorm in the target area show that the cumulative rainfall decreases from south to north. Except for the rainstorm center in the south, the areas with heavy rainfall in the southwest and southeast are significantly amplified. Figure 6 and Figure 7 The isohyet map before and after the relocation of the B3 rainstorm in the target area shows that the cumulative rainfall decreases from south to north. The center of the rainstorm in different sessions did not shift before and after the relocation. The distribution of the isohyet map conforms to the natural law conditions and maintains the water vapor distribution characteristics of the target area. At the same time, the rainstorm centers of the precipitation sessions in the target area are all located in the southern part of the region, maintaining the distribution characteristics of the geographical terrain conditions, which is in line with the rainstorm law of the B basin.

[0056] To further analyze the results of the rainstorm displacement, this example uses the Thiessen polygon method to calculate the cumulative rainfall in the watershed. The cumulative rainfall in the target area before and after the displacement of the B1 rainstorm increased from 255.8 mm to 1539.4 mm; the cumulative rainfall in the target area before and after the B2 rainstorm increased from 466.8 mm to 1785.2 mm; the cumulative rainfall in the target area before and after the B3 rainstorm increased from 474.0 mm to 1788.9 mm. The cumulative rainfall of the displacement area was 1787.4 mm, and the cumulative rainfall of the three sessions was magnified by 6 times, 3.8 times and 3.7 times respectively. The rainfall sessions with different rainfall totals and durations maintained the consistency of the cumulative rainfall values ​​in the displacement area. At the same time, the rainfall of the B1 session before the displacement was significantly less than that of the B2 and B3 sessions, and the cumulative rainfall of the B1 session after the rainstorm displacement was also small, maintaining the difference in the cumulative rainfall values ​​of different sessions in the target area. In this example, three rainstorms in Basin B were relocated, with the maximum possible rainfall being 1788.9 mm. At the same time, after the relocation of the three rainstorms, the rainstorm centers were all located in the southern part of Basin B, which is in line with the rationality of the rainstorm relocation; it provides a reliable basis for formulating corresponding plans and measures in advance to deal with possible extreme precipitation events in the future.

[0057] Although embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A rainstorm displacement method based on sorting method and current spatial distribution, characterized by: include, S1, collect rainfall data in the target area and determine the duration T of the rainstorm to be displaced in the target area, where T is a positive number; S2, select a rainstorm displacement area and obtain typical rainstorms in the rainstorm displacement area; S3, identifying the rainstorm center of the rainstorm to be relocated in the target area and sorting the rain stations in the target area according to the rainfall amounts of the rain stations in the target area; S4, identifying typical rainstorm centers in the rainstorm relocation area and sorting the rainstorm relocation area raingauge stations according to the rainfall of the target area raingauge stations; S5, shifting the corresponding rainstorm sequence of the rain gauge stations sorted according to the rainfall amount in the rainstorm shifting area to the rain gauge stations with corresponding sequence numbers in the target area; S6, calculating the cumulative rainfall in the target area according to the rainstorm sequence transferred from each rain gauge station in the target area.

2. The method for rainstorm displacement based on sorting method and current spatial distribution according to claim 1, characterized in that: The rainstorm displacement area selected in step 2 includes rainstorms with rainfall process data records that occur at least once in a hundred years and the duration of the rainstorm is greater than or equal to T.

3. The method for rainstorm displacement based on sorting method and current spatial distribution according to claim 2, characterized in that: The typical rainstorm is the corresponding rainstorm with rainfall process data and the largest cumulative rainfall in the rainstorm displacement area.

4. The method for rainstorm displacement based on sorting method and current spatial distribution according to claim 3, characterized in that: The method for obtaining the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced in step S5 is as follows: determine whether the duration of the typical rainstorm is equal to T. If so, the rainstorm sequence of each raingauge corresponding to the typical rainstorm in the rainstorm displacement area is the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced. If not, obtain the time period T1 corresponding to the duration T and the maximum accumulated rainfall in the typical rainstorm sequence, and the rainstorm sequence of each raingauge in the rainstorm displacement area in the time period T1 is used as the rainstorm sequence of each raingauge in the rainstorm displacement area to be displaced.

5. The method for rainstorm displacement based on sorting method and current spatial distribution according to claim 4, characterized in that: The step 3 of identifying the rainstorm center of the target area to be displaced and sorting the rain stations in the target area according to the rainfall of the rain stations in the target area specifically includes: calculating the cumulative rainfall of each rain station in the target area for a period of time T, and sorting the calculated cumulative rainfall of each rain station, and the cumulative rainfall of the rain station is recorded as P s,i , where i represents the number of the rainfall station in the target area, i is a natural number greater than or equal to 1, and the smaller i is, the higher the corresponding P s,i The larger the value.

6. The method for rainstorm displacement based on sorting method and current spatial distribution according to claim 5, characterized in that: The step S4 of identifying the typical rainstorm center in the rainstorm relocation area and sorting the rainstorm relocation area rainstorm stations according to the rainfall of the target area rainstorm stations specifically includes: calculating the cumulative rainfall of each rainstorm relocation area rainstorm station for a period of time T, and sorting the calculated cumulative rainfall of each rainstorm station, and the cumulative rainfall of the rainstorm station is recorded as P x,j , where j represents the number of the rain gauge station in the rainstorm relocation area, j is a natural number greater than or equal to 1, and the smaller j is, the corresponding P x,j The larger the value.

7. The method for rainstorm displacement based on sorting method and current spatial distribution according to claim 1, characterized in that: After executing step S2, the method also includes the step of equal-step-length reorganization of the rainstorms to be displaced in the target area and the typical rainstorm sequences in the rainstorm displacement area.

8. The method for rainstorm displacement based on sorting method and current spatial distribution according to claim 7, characterized in that: The equal-step reorganization specifically includes reorganizing the rainfall sequence into a rainfall amount sequence with a step length of 1 hour.

9. The method for rainstorm displacement based on sorting method and current spatial distribution according to claim 8, characterized in that: The equal-step reorganization is specifically performed by an interpolation method.

10. The method for rainstorm displacement based on sorting method and current spatial distribution according to claim 1, characterized in that: The calculation of the cumulative rainfall in the target area in S6 is specifically performed using the Thiessen polygon method.

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