A zoning method for risk prevention of extreme precipitation-geological disaster chain

Abstract

The application discloses a kind of division methods for extreme precipitation-geological disaster chain risk prevention, comprising the following steps: S1. the environment background division of to-be-division region is carried out;S2. with small watershed as basis evaluation unit, respectively calculate evaluation factor;S3. risk prevention index is evaluated, and risk prevention index is divided into grade, based on risk prevention index grade distribution, under each environment background division risk prevention grade area;S4. evaluation factor is respectively divided into grade, and the basic evaluation unit of element grade combination is merged, and risk prevention target area is divided;S5. naming is carried out to each level area, and comprehensive division map is drawn.The application achieves the purpose of extreme precipitation-geological disaster chain risk prevention, small and medium-sized river basin as basis unit division, and the purpose of simultaneously showing the risk prevention importance and main prevention direction of each area on a map, which helps to provide more comprehensive and specific risk spatial information for risk prevention work deployment.

Description

Technical Field

[0001] This invention relates to the field of natural disaster zoning technology, and more specifically to a zoning method for risk prevention of extreme precipitation-geological disaster chains. Background Technology

[0002] Disaster zoning is a crucial foundation for risk prevention. Utilizing zoning techniques to identify the spatial pattern of disasters and divide a large area into several smaller areas with different disaster intensities or risk levels is an important way to determine risk prevention measures tailored to local conditions. It helps to clarify the key areas, key directions, inter-regional coordination, and priorities of disaster risk management and response work, facilitating decision-makers to make scientific and efficient deployments for natural disaster risk prevention.

[0003] A series of geological hazard zoning studies have been conducted both domestically and internationally. These studies primarily aim to identify areas with high incidence or high risk of disasters. In addition, there are zoning studies that comprehensively consider the geological hazards, the importance of the disaster-bearing bodies, and their adaptability, as well as risk zoning studies based on geological hazard risk assessments. Furthermore, some hazard zone delineation studies based on extreme rainfall early warning and forecast values ​​have been conducted specifically targeting the extreme precipitation-geological hazard chain.

[0004] However, when carrying out natural disaster risk prevention work, it is best to consider both the key areas for prevention and the key prevention elements in each area. Based on the risk elements of the extreme precipitation-geological disaster chain, prevention elements include the triggering nature of extreme precipitation, the susceptibility to geological disasters, the vulnerability of disaster-bearing bodies, the exposure level of disaster-bearing bodies, and the adaptability of disaster-bearing bodies. Furthermore, the spatial relationship between disaster-bearing bodies and disaster sites is also an important factor to consider when setting up prevention measures. Clearly defining the key prevention elements for each area helps to combine and allocate prevention measures such as early warning triggering, reducing susceptibility, reducing exposure, reducing vulnerability, improving adaptability, and planning relocation as needed. Past extreme precipitation-geological disaster zoning work has not been able to provide both aspects of information simultaneously on a single map, focusing more on providing information on key areas for prevention and lacking a comprehensive consideration of key prevention elements.

[0005] Furthermore, considering the geological disaster-prone environment, the long-term erosion of watershed systems significantly impacts the accumulation of sediment and the development of slope potential energy for geological disasters such as landslides, collapses, and debris flows. From the perspective of extreme precipitation, the runoff process can continuously stimulate potential geological disaster sites along its course, threatening nearby residents, buildings, transportation, and crops. Therefore, the spatial pattern of small and medium-sized watershed units and their layout may be of reference value for the prevention, emergency response, and management of extreme precipitation-geological disaster chains, and it is necessary to consider the spatial pattern of small and medium-sized watersheds when conducting zoning work.

[0006] In summary, how to provide a multi-level zoning method that divides the study area into areas with different risk prevention importance levels as the upper level and areas with different prevention focus elements as the lower level, and how to incorporate small and medium-sized watersheds into the zoning method, are problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, and in view of the shortcomings of existing natural disaster risk prevention zoning technology that does not simultaneously display key prevention areas and key prevention elements on a single map, this invention provides a more comprehensive zoning method for natural disaster risk prevention.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A zoning method for risk prevention in the extreme precipitation-geological hazard chain includes the following steps:

[0010] S1. Using the distribution map of watersheds at or above the third level, and following the basic zoning principles, the area to be zoned is divided into environmental background zones, and the result is a first-level zone;

[0011] S2. Using small watersheds as the basic assessment unit, calculate the assessment elements respectively. The assessment elements include: the triggering nature (T) and susceptibility (P) of the disaster chain, the vulnerability (V), exposure (E), and adaptability (A) of the disaster-bearing body, and the distance index from the settlement to the disaster point (D).

[0012] S3. On each basic assessment unit, the Risk Prevention Index (RPI) is assessed by comprehensively evaluating the assessment elements, and the RPI is divided into levels. Based on the distribution of the risk prevention index levels, risk prevention level zones are divided into secondary zones under each primary zone according to the basic zoning principle.

[0013] S4. Divide the assessment elements into three levels: high, medium, and low, according to the quantile method. In each secondary zone, merge the basic assessment units with the same combination of element levels, and divide the risk prevention target zone into a tertiary zone according to the basic zoning principle.

[0014] S5. Name the regions at each level and draw a comprehensive zoning map.

[0015] Preferably, the specific contents of the basic zoning principles include:

[0016] (1) Spatial continuity principle: also known as the regional conjugate principle, it means that the divided regions should maintain spatial continuity and be a complete and independent unit. Specifically, it means that the initially divided regions of the same type should be processed by taking the larger and removing the smaller and making them spatially connected to avoid the existence of spatially separated scattered points or small areas in the divided regions.

[0017] (2) Relative consistency principle: refers to the fact that within a region, the value of the element is consistent with that outside the region. Specifically, when dividing the region, the differences between elements in different regions and the similarity of elements in the same region should be maximized.

[0018] (3) The principle of combining with administrative boundaries: superimpose administrative unit boundaries during the division process to assist in the judgment; the specific content is: superimpose administrative unit boundaries during the division process to further divide the area that spans different administrative units, and replace the administrative boundary with the administrative boundary.

[0019] Preferably, step S2 specifically includes:

[0020] S21. Using the maximum precipitation over five consecutive days (R5d) to assess the triggerability of the disaster chain (T):

[0021]

[0022] Where i is the watershed number, R5d i T represents the maximum five-day precipitation in basin i. i For the disaster chain triggering property of watershed i, Max(R5d) and Min(R5d) are the maximum and minimum R5d among all small watersheds in the study area, respectively.

[0023] S22. Using annual precipitation P1, topographic relief P2, normalized vegetation index P3, soil erosion P4, rock hardness P5, distance to water system P6, distance to fault zone P7, and human activity index P8 as indicators, principal component analysis is used to assess the susceptibility of disaster chains P.

[0024] S23. Using population density V1 and the ratio of old to young population V2 as indicators, the normalized weighted method is used to assess the vulnerability V of the disaster-bearing body.

[0025] S24. Exposure level E is indicated by the total population POP.

[0026] S25. Using the Human Development Index (A1), GDP per capita (A2), and transportation advantage (A3) as indicators, the normalized weighted method is used to assess adaptability (A).

[0027] S26. Calculate the closest distance D1 and the average distance D2 between residential areas and geological disaster sites. Using D1 and D2 as indicators, use the normalized weighted method to evaluate the distance index D between residential areas and disaster sites.

[0028] Preferably, the specific content of calculating P includes:

[0029] Principal component analysis was used to extract the principal components of the index set and the variance contribution rate of each component.

[0030] Using the variance contribution rate of each component as a weight, the susceptibility P is obtained by weighting the component values ​​of each principal component:

[0031] P i =∑(M ij ×F j )

[0032] In the formula, P i M is the susceptibility index for watershed i. ij For the principal component j of the i-th watershed, F j The variance contribution rate of principal component j.

[0033] Preferably, the specific calculations of V, A, and D include:

[0034] Normalize each indicator separately:

[0035]

[0036] In the formula, X i Let X and X' be the indices of watershed i. i Let X be the normalized value of watershed i, and Max(X) and Min(X) be the maximum and minimum values ​​of X among all small watersheds in the study area, respectively.

[0037] Then, within each sub-basin, the normalized indicators are weighted, with the weights determined using an expert scoring method, thereby obtaining the corresponding element evaluation values:

[0038] Y i =∑(X ij ×w j )

[0039] In the formula, Y i The elements for small watershed i include: vulnerability V, or adaptability A, or the distance index from settlement to disaster point D, X ij For the j-th index of the i-th watershed, w j Let be the weight of the j-th indicator.

[0040] Preferably, the risk prevention index assessment method in step S3 is as follows:

[0041]

[0042] In the formula, RPI i The Risk Prevention Index (RIP) for small watershed i.

[0043] Preferably, the specific content of the naming of the zoning results includes:

[0044] (1) Name the first-level zones with the names of the third-level or higher watersheds corresponding to each first-level zone, and mark them on the comprehensive zoning map with the first letter of the corresponding watershed name capitalized.

[0045] (2) The secondary zones are named according to their risk prevention levels, including high-risk prevention zones, medium-risk prevention zones and low-risk prevention zones, and are marked with the corresponding Roman numerals on the comprehensive zoning map;

[0046] (3) Name the three-level zones according to the combination of T, P, V, E, A, and D levels, and mark them on the comprehensive zoning map:

[0047] If T, P, V, or E are high or medium, or A or D are low or medium, then T, P, V, E, A, or D are risk prevention targets, and they are marked differently according to the type and level of the element.

[0048] If T, P, V, and E are all low, and A and D are high, then there are no risk prevention targets within the current risk prevention target area, and it is marked as a stable area on the comprehensive zoning map.

[0049] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a zoning method for risk prevention of extreme precipitation-geological disaster chain. The present invention achieves the purpose of simultaneously displaying the importance of natural disaster risk prevention and the main prevention direction of each region on a single map, which helps to provide more comprehensive and specific risk spatial information for risk prevention work deployment. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0051] Figure 1 This is a flowchart illustrating a zoning method for risk prevention in the extreme precipitation-geological disaster chain according to the present invention. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] This invention discloses a zoning method for risk prevention in the extreme precipitation-geological disaster chain, such as... Figure 1 As shown, it includes the following steps:

[0054] S1. Using the distribution map of watersheds at or above the third level, and following the basic zoning principles, the area to be zoned is divided into environmental background zones, and the result is a first-level zone;

[0055] S2. Based on small watersheds as the basic assessment unit, the assessment elements are calculated separately. The assessment elements include: the triggering nature (T) and susceptibility (P) of the disaster chain, the vulnerability (V), exposure (E), and adaptability (A) of the disaster-bearing body, and the distance index from the settlement to the disaster point (D).

[0056] S3. On each basic assessment unit, the risk prevention index (RPI) is assessed by comprehensively evaluating the assessment elements, and the risk prevention index (RPI) is divided into levels. Based on the distribution of risk prevention index levels, risk prevention level zones are divided into secondary zones under each primary zone in accordance with the basic zoning principle.

[0057] S4. Divide the assessment elements into three levels: high, medium, and low, according to the quantile method. In each secondary zone, merge the basic assessment units with the same combination of element levels, and divide the risk prevention target area into a tertiary zone according to the basic zoning principle.

[0058] S5. Name the regions at each level and draw a comprehensive zoning map.

[0059] To further implement the above plan, the specific contents of the basic zoning principles include:

[0060] (1) Spatial continuity principle: also known as the regional conjugate principle, it means that the divided regions should maintain spatial continuity and be a complete and independent unit. Specifically, it means that the initially divided regions of the same type should be processed by taking the larger and removing the smaller and making them spatially connected to avoid the existence of spatially separated scattered points or small areas in the divided regions.

[0061] (2) Relative consistency principle: refers to the fact that within a region, the value of the element is consistent with that outside the region. Specifically, when dividing the region, the differences between elements in different regions and the similarity of elements in the same region should be maximized.

[0062] (3) The principle of combining with administrative boundaries: superimpose administrative unit boundaries during the division process to assist in the judgment; the specific content is: superimpose administrative unit boundaries during the division process to further divide the area that spans different administrative units, and replace the administrative boundary with the administrative boundary.

[0063] To further implement the above scheme, step S2 specifically includes:

[0064] S21. Using the maximum precipitation over five consecutive days (R5d) to assess the triggerability of the disaster chain (T):

[0065]

[0066] Where i is the watershed number, R5d i T represents the maximum five-day precipitation in basin i. i For the disaster chain triggering property of watershed i, Max(R5d) and Min(R5d) are the maximum and minimum R5d among all small watersheds in the study area, respectively.

[0067] S22. Using annual precipitation P1, topographic relief P2, normalized vegetation index P3, soil erosion P4, rock hardness P5, distance to water system P6, distance to fault zone P7, and human activity index P8 as indicators, principal component analysis is used to assess the susceptibility of disaster chains P.

[0068] S23. Using population density V1, the ratio of old to young population V2, the proportion of female population V3, and the proportion of illiterate population V4 as indicators, the normalized weighted method is used to assess the vulnerability of the disaster-bearing body V.

[0069] S24. Exposure level E is indicated by the total population POP.

[0070] S25. Using the Human Development Index (A1), GDP per capita (A2), and transportation advantage (A3) as indicators, the normalized weighted method is used to assess adaptability (A).

[0071] S26. Calculate the closest distance D1 and the average distance D2 between residential areas and geological disaster sites. Using D1 and D2 as indicators, use the normalized weighted method to evaluate the distance index D between residential areas and disaster sites.

[0072] To further implement the above scheme, the specific calculation of P includes:

[0073] Principal component analysis was used to extract the principal components of the index set and the variance contribution rate of each component.

[0074] Using the variance contribution rate of each component as a weight, the susceptibility P is obtained by weighting the component values ​​of each principal component:

[0075] P i =∑(M ij ×F j )

[0076] In the formula, P i M is the susceptibility index for watershed i. ij For the principal component j of the i-th watershed, F j The variance contribution rate of principal component j.

[0077] To further implement the above scheme, the specific calculations of V, A, and D include:

[0078] Normalize each indicator separately:

[0079]

[0080] In the formula, X i Let X and X' be the indices of watershed i. i Let X be the normalized value of watershed i, and Max(X) and Min(X) be the maximum and minimum values ​​of X among all small watersheds in the study area, respectively.

[0081] Then, within each sub-basin, the normalized indicators are weighted, with the weights determined using an expert scoring method, thereby obtaining the corresponding element evaluation values:

[0082] Y i =∑(X ij ×w j )

[0083] In the formula, Y i The elements for small watershed i include: vulnerability V, adaptability A, or the distance index from settlement to disaster point D, X. ij For the j-th index of the i-th watershed, w j Let be the weight of the j-th indicator.

[0084] To further implement the above plan, the risk prevention index assessment method in step S3 is as follows:

[0085]

[0086] In the formula, RPI i The Risk Prevention Index (RIP) for small watershed i.

[0087] To further implement the above plan, the specific details of the naming of the zoning results include:

[0088] (1) Name the first-level zones with the names of the third-level or higher watersheds corresponding to each first-level zone, and mark them on the comprehensive zoning map with the first letter of the corresponding watershed name capitalized.

[0089] (2) The secondary zones are named according to their risk prevention levels, including high-risk prevention zones, medium-risk prevention zones and low-risk prevention zones, and are marked with the corresponding Roman numerals on the comprehensive zoning map;

[0090] (3) Name the three-level zones according to the combination of T, P, V, E, A, and D levels, and mark them on the comprehensive zoning map:

[0091] If T, P, V, or E are high or medium, or A or D are low or medium, then T, P, V, E, A, or D are risk prevention targets, and they are marked differently according to the type and level of the element.

[0092] If T, P, V, and E are all low, and A and D are high, then there are no risk prevention targets within the current risk prevention target area, and it is marked as a stable area on the comprehensive zoning map.

[0093] Table 1 Naming and Marking of Risk Prevention Target Areas

[0094]

[0095] Integrating the results of the first, second, and third-level zoning, a zoning system and final labels are formed, with each level of label connected by a "-". For areas with completely identical names, "-1", "-2", etc., are added after the name and label to distinguish them. A comprehensive zoning map is then drawn.

[0096] The invention will be further illustrated by examples below:

[0097] 1. Study Area

[0098] The study area was selected from regions where geological disasters frequently occur.

[0099] 2. Environmental background area division

[0100] The study area was zoned based on the distribution map of my country's three-level river basins.

[0101] It is divided into three primary zones: the southeastern watershed zone, the western Shihezi watershed zone, and the northeastern watershed zone.

[0102] 3. Calculation of Risk Prevention Elements

[0103] Using small watersheds as the basic assessment unit, the triggering tendency (T) and susceptibility (P) of the disaster chain, the vulnerability (V), exposure (E), and adaptability (A) of the disaster-bearing body, and the distance index from the settlement to the disaster point (D) are calculated respectively.

[0104] 4. Risk prevention level zone division

[0105] For each basic assessment unit, the Risk Prevention Index (RPI) is assessed by comprehensively evaluating the assessment elements. The RPI is divided into three levels: high (0.6-1.0), medium (0.4-0.6), and low (0.0-0.4) using the natural breakpoint method.

[0106] Finally, based on the risk prevention index level distribution, risk prevention level zones were divided under each first-level zone according to the principles of spatial continuity, relative consistency, and integration with administrative boundaries.

[0107] 5. Risk prevention target area delineation

[0108] The six elements T, P, V, E, A, and D were divided into three levels: high, medium, and low using the quantile method.

[0109] Table 2 Classification of Risk Prevention Elements

[0110]

[0111] Then, under each secondary unit, rasters with the same element level combination are merged, and risk prevention target areas are delineated according to zoning principles, ultimately generating a zoning system.

[0112] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0113] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A zoning method for risk prevention in the extreme precipitation-geological disaster chain, characterized in that, Includes the following steps: S1. Using the distribution map of watersheds at or above the third level, and following the basic zoning principles, the area to be zoned is divided into environmental background zones, and the result is a first-level zone; S2. Using small watersheds as the basic assessment unit, calculate the assessment elements respectively. The assessment elements include: the triggering nature (T) and susceptibility (P) of the disaster chain, the vulnerability (V), exposure (E), and adaptability (A) of the disaster-bearing body, and the distance index from the settlement to the disaster point (D). S3. On each basic assessment unit, the Risk Prevention Index (RPI) is assessed by comprehensively evaluating the assessment elements, and the RPI is divided into levels. Based on the distribution of the risk prevention index levels, risk prevention level zones are divided into secondary zones under each primary zone according to the basic zoning principle. S4. Divide the assessment elements into three levels: high, medium, and low, according to the quantile method. In each secondary zone, merge the basic assessment units with the same combination of element levels, and divide the risk prevention target zone into a tertiary zone according to the basic zoning principle. S5. Name the regions at each level and draw a comprehensive zoning map; Step S2 specifically includes: S21. Using the maximum precipitation over five consecutive days (R5d) to assess the triggerability of the disaster chain (T): Where i is the watershed number, R5d i T represents the maximum five-day precipitation in basin i. i For the disaster chain triggering property of watershed i, Max(R5d) and Min(R5d) are the maximum and minimum R5d among all small watersheds in the study area, respectively. S22. Using annual precipitation P1, topographic relief P2, normalized vegetation index P3, soil erosion P4, rock hardness P5, distance to water system P6, distance to fault zone P7, and human activity index P8 as indicators, principal component analysis is used to assess the susceptibility of disaster chains P. S23. Using population density V1 and the ratio of old to young population V2 as indicators, the normalized weighted method is used to assess the vulnerability V of the disaster-bearing body. S24. Exposure level E is indicated by the total population POP. S25. Using the Human Development Index (A1), GDP per capita (A2), and transportation advantage (A3) as indicators, the normalized weighted method is used to assess adaptability (A). S26. Calculate the closest distance D1 and the average distance D2 between residential areas and geological disaster sites. Using D1 and D2 as indicators, use the normalized weighted method to evaluate the distance index D between residential areas and disaster sites.

2. The zoning method for risk prevention of extreme precipitation-geological disaster chain according to claim 1, characterized in that, The specific contents of the basic zoning principles include: (1) Spatial continuity principle: also known as the regional conjugate principle, it means that the divided regions should maintain spatial continuity and be a complete and independent unit. Specifically, it means that the initially divided regions of the same type should be processed by taking the larger and removing the smaller and making them spatially connected to avoid the existence of spatially separated scattered points or small areas in the divided regions. (2) Relative consistency principle: refers to the fact that within a region, the value of the element is consistent with that outside the region. Specifically, when dividing the region, the differences between elements in different regions and the similarity of elements in the same region should be maximized. (3) The principle of combining with administrative boundaries: superimpose administrative unit boundaries during the division process to assist in the judgment; the specific content is: superimpose administrative unit boundaries during the division process to further divide the area that spans different administrative units, and replace the administrative boundary with the administrative boundary.

3. The zoning method for risk prevention of extreme precipitation-geological disaster chain according to claim 1, characterized in that, The specific steps involved in calculating P include: Principal component analysis was used to extract the principal components of the index set and the variance contribution rate of each component. Using the variance contribution rate of each component as a weight, the susceptibility P is obtained by weighting the component values ​​of each principal component: P i =∑(M ij ×F j ) In the formula, P i M is the susceptibility index for watershed i. ij For the principal component j of the i-th watershed, F j The variance contribution rate of principal component j.

4. The zoning method for risk prevention of extreme precipitation-geological disaster chain according to claim 1, characterized in that, The specific calculations of V, A, and D include: Normalize each indicator separately: In the formula, X i Let X and X' be the indices of small watershed i. i Let X be the normalized value of watershed i, and Max(X) and Min(X) be the maximum and minimum values ​​of X among all small watersheds in the study area, respectively. Then, within each sub-basin, the normalized indicators are weighted, with the weights determined using an expert scoring method, thereby obtaining the corresponding element evaluation values: AND i =∑(X ij ×w j ) In the formula, Y i The elements for small watershed i include: vulnerability V, or adaptability A, or the distance index from settlement to disaster point D, X ij For the j-th index of the i-th watershed, w j Let be the weight of the j-th indicator.

5. A zoning method for risk prevention of extreme precipitation-geological disaster chains according to claim 1, characterized in that, The risk prevention index assessment method in step S3 is as follows: In the formula, RPI i The risk prevention index (RPI) for small watershed i.

6. A zoning method for risk prevention of extreme precipitation-geological disaster chains according to claim 1, characterized in that, The specific details of the naming of the administrative division results include: (1) Name the first-level zones with the names of the third-level or higher watersheds corresponding to each first-level zone, and mark them on the comprehensive zoning map with the first letter of the corresponding watershed name capitalized. (2) The secondary zones are named according to their risk prevention levels, including high-risk prevention zones, medium-risk prevention zones and low-risk prevention zones, and are marked with the corresponding Roman numerals on the comprehensive zoning map; (3) Name the three-level zones according to the combination of T, P, V, E, A, and D levels, and mark them on the comprehensive zoning map: If T, P, V, or E are high or medium, or A or D are low or medium, then T, P, V, E, A, or D are risk prevention targets, and they are marked differently according to the type and level of the element. If T, P, V, and E are all low, and A and D are high, then there are no risk prevention targets within the current risk prevention target area, and it is marked as a stable area on the comprehensive zoning map.

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