Basin unit-based geological disaster meteorological risk early warning simplified method

Abstract

The invention discloses a geological disaster meteorological risk early warning simplified method based on drainage basin units. The method comprises the following steps: S1, geological disaster susceptibility zoning of all drainage basin units in a research area; s2, obtaining the number and distribution condition of drainage basin units with geological disasters in the research area; s3, rainfall values of all drainage basin units in the research area are obtained, and rainfall intervals are divided; s4, counting the number U and the number V of all drainage basin units in each susceptible area and each rainfall interval in the research area; s5, counting the number of drainage basin units with geological disasters in each susceptible area and each rainfall area in the research area; s6, calculating the geological disaster occurrence probability of each susceptible area and each rainfall interval; and S7, dividing early warning grades according to the probability value. According to the method, a scientific basis can be provided for prevention and early warning of geological disasters, and the accuracy and timeliness of early warning are improved, so that the loss caused by the geological disasters is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of geological disaster early warning, and in particular to a simplified method for meteorological risk early warning of geological disasters based on watershed units. Background Art

[0002] With the increase of global climate change and extreme weather events, geological disasters triggered by extreme rainfall events are becoming increasingly frequent, posing a serious threat to the safety of people's lives and property. Geological disasters, such as landslides, debris flows and collapses, not only cause direct casualties and economic losses, but also may trigger secondary disasters such as reservoir surges and barrier lakes, further exacerbating the disaster consequences and losses.

[0003] Although the demand for meteorological risk early warning of geological disasters is increasing, the research and application of early warning models still face many challenges. First, the induction mechanism of geological disasters is complex, involving a variety of geographical, geological and environmental factors, such as slope, elevation, lithology, vegetation conditions, etc., and rainfall is the most important triggering condition. Second, the existing early warning models are restricted by the complex induction mechanism of geological disasters in the study area and the availability of investigation and monitoring data, resulting in limited regional early warning accuracy and insufficient refinement. In addition, the existing work has not effectively introduced dynamic rainfall factors into the occurrence probability model, and it is difficult to dynamically forecast the occurrence of geological disasters.

[0004] Therefore, it is necessary to design a simplified method for meteorological risk early warning of geological disasters based on watershed units to overcome the above problems. Summary of the Invention

[0005] In order to avoid the above problems, a simplified method for meteorological risk early warning of geological disasters based on watershed units is provided, which provides scientific guidance for meteorological risk early warning of geological disasters through a more refined and simpler data processing process to reduce the losses caused by geological disasters.

[0006] A simplified method for meteorological risk early warning of geological disasters based on watershed units provided by the present invention includes the following steps:

[0007] S1. Geological disaster susceptibility zoning of all watershed units in the study area;

[0008] S2. Obtaining the number and distribution of watershed units with geological disasters in the study area;

[0009] S3. Obtaining the rainfall values of all watershed units in the study area and dividing the rainfall intervals;

[0010] S4. Counting the numbers U and V of all watershed units in the study area in each susceptible area and each rainfall interval;

[0011] S5. Count the number of watershed units with geological disasters in each susceptible area and each rainfall interval in the study area;

[0012] S6. Calculate the occurrence probability of geological disasters in each susceptible area and each rainfall interval;

[0013] S7. Divide the warning levels according to the probability values.

[0014] Preferably, step S1 specifically includes: according to the collected geological disaster data and the distribution data of their influencing factors in the study area, extract the influencing factors onto each watershed unit in the study area, then select a model to calculate the susceptibility value, and divide it into U susceptible areas by the natural breakpoint method according to the size of the susceptibility value.

[0015] Preferably, in step S1, the information amount model is used to quantify the influencing factors and calculate the geological disaster susceptibility value of each watershed unit. Assuming that I influencing factors are selected, each influencing factor is divided into J levels according to the size or type of its own value, and the study area is divided into Y watershed units in total; then the susceptibility value calculation formula is as follows:

[0016]

[0017] Q y =∑X yij ,

[0018] In the formula, i represents the i-th influencing factor, i ranges from 1 to I; j represents the j-th level of the i-th influencing factor, j ranges from 1 to J; y represents the y-th watershed unit, y ranges from 1 to Y; X yij represents the information amount value of the y-th watershed unit in the study area for the j-th level of the i-th influencing factor; H represents the total area of the watershed units with geological disasters in the study area; H ij represents the total area of the watershed units with geological disasters in the study area for the j-th level of the i-th influencing factor; when there are no geological disasters, assign H ij the value of 0.001; A represents the total area of all watershed units in the study area, that is, the area of the study area; A ij represents the total area of the watershed units at the j-th level of the i-th influencing factor in the study area; Q y represents the information amount value of the y-th watershed unit when there are I influencing factors and each is divided into J levels, that is, the susceptibility value. Calculate the susceptibility values of the Y watershed units in the study area according to this method.

[0019] The information amount model is a susceptibility evaluation model based on information theory. In the process of geological disaster occurrence, the size of the information amount value is used to represent the possibility of geological disaster occurrence. The information amount values of each factor are superimposed to obtain the total information amount value, that is, the disaster susceptibility index and the susceptibility value.

[0020] Preferably, step S2 specifically includes: according to the spatial distribution of geological disasters, determining the basin units to which each geological disaster belongs, performing spatial analysis through GIS technology, identifying the corresponding relationship between geological disaster points and basin units, and obtaining the number and distribution of basin units with geological disasters in the study area.

[0021] Preferably, step S3 specifically includes: according to the coordinates of each meteorological station and the rainfall data recorded by rain gauges, after screening, using Kriging method to interpolate the rainfall data, then assigning the average rainfall to the Y basin units in the study area, and dividing the rainfall into V rainfall intervals.

[0022] Preferably, in step S6, the calculation method is to divide the number of basin units with geological disasters in each prone area by the number of basin units in the corresponding interval.

[0023] Preferably, the specific calculation formula in step S6 is as follows:

[0024]

[0025] In the formula, u represents the u-th prone area among U prone areas, where u ranges from 1 to U; v represents the v-th rainfall interval among V rainfall intervals, where v ranges from 1 to V; P uv represents the probability of geological disasters occurring in the basin units of the u-th prone area and the v-th rainfall interval; n uv represents the number of basin units with geological disasters in the u-th prone area and the v-th rainfall interval; N uv represents the number of basin units in the u-th prone area and the v-th rainfall interval.

[0026] Preferably, in step S7, the warning levels are divided into red warning, orange warning, yellow warning, blue warning and no warning level.

[0027] Preferably, in step S7, when 0.8 ≤ P uv ≤ 1, it is the red warning level; when 0.6 ≤ P uv <0.8, it is the orange warning level; when 0.4 ≤ P uv <0.6, it is the yellow warning level; when 0.2 ≤ P uv <0.4, it is the blue warning level; when 0 ≤ P uv <0.2, it is the no warning level.

[0028] Compared with the prior art, the present invention has the following beneficial effects: By integrating data on past extreme rainfall events, the present invention establishes a simplified method for meteorological risk warning of geological disasters based on watershed units, enabling the warning model to not only consider the dynamic changes in rainfall, but also making the data processing process more concise and clear; rainfall is one of the main triggering factors for geological disasters, and the integration of dynamic rainfall data significantly improves the timeliness and accuracy of the warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flowchart of a simplified method for meteorological risk warning of geological disasters based on watershed units according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be introduced below in conjunction with the embodiments and the drawings.

[0031] As Figure 1 shown, a simplified method for meteorological risk warning of geological disasters based on watershed units provided in this embodiment includes the following steps:

[0032] S1. Geological disaster susceptibility zoning of watershed units

[0033] First, it is necessary to extract the influencing factors for susceptibility zoning of each watershed unit, including geological conditions, topography and landforms, land use types, vegetation coverage, and human engineering activities, etc. Then, use these influencing factors to calculate the susceptibility of each watershed unit. The Information Value (IV) model is used to quantitatively evaluate the index factors, calculate the geological disaster susceptibility values of each watershed unit, and then divide the region into high-susceptibility areas, medium-susceptibility areas, low-susceptibility areas, and non-susceptibility areas according to the susceptibility values using the natural breakpoint method, obtaining a geological disaster susceptibility zoning map. That is, the number U of susceptible areas in this embodiment is 4.

[0034] The information value method has the advantages of objectivity and quantification, and can provide scientific and accurate decision-making support for the prevention and treatment of geological disasters. The information value ranges from (-∞ to +∞),

[0035] Assume that I influencing factors are selected, each influencing factor is divided into J levels according to the value size or type, and the study area is divided into Y watershed units in total; then the susceptibility value calculation formula is as follows:

[0036]

[0037] Q y = ∑X yij ,

[0038] In the formula, i represents the i-th influencing factor, where i ranges from 1 to I; j represents the j-th level of the i-th influencing factor, where j ranges from 1 to J; y represents the y-th watershed unit, where y ranges from 1 to Y; X yij represents the information value of the y-th watershed unit in the study area for the j-th level of the i-th influencing factor; H represents the total area of the watershed units with geological disasters in the study area; H ij represents the total area of the watershed units with geological disasters in the study area for the j-th level of the i-th influencing factor; when there are no geological disasters, H ij is assigned a value of 0.001; A represents the total area of all watershed units in the study area, that is, the area of the study area; A ij represents the total area of the watershed units for the j-th level of the i-th influencing factor in the study area; Q y represents the information value, that is, the susceptibility value, of the y-th watershed unit when there are I influencing factors each divided into J levels. The susceptibility values of the Y watershed units in the study area are calculated in this way.

[0039] According to the information values, that is, the susceptibility values, of each watershed unit calculated by the above formula, all watershed units are divided into high-susceptibility areas, medium-susceptibility areas, low-susceptibility areas, and non-susceptibility areas using the natural breaks method.

[0040] S2. Obtain the number and distribution of the watershed units with geological disasters in the study area

[0041] According to the distribution of geological disasters, determine the watershed units to which each geological disaster belongs. Through spatial analysis using GIS technology, identify the corresponding relationship between geological disaster points and watershed units, and obtain the number and distribution of the watershed units with geological disasters, providing basic data for subsequent in-depth statistics and calculations.

[0042] S3. Obtain the rainfall values of all watershed units in the study area and divide the rainfall intervals

[0043] According to the coordinates of each meteorological station and the rainfall gauge record data, after data screening, import the rainfall gauge positions of the rainfall stations into GIS, then use the Kriging method to interpolate the rainfall for the screened data to obtain the rainfall values of the entire area, and then use the extraction tool to extract the rainfall and assign the average value to each watershed unit, and divide the rainfall intervals. This step is crucial for considering the dynamic rainfall factor in the early warning model and is essential for improving the accuracy of the early warning.

[0044] S4. Statistically obtain the quantities U and V of all watershed units in the study area in each susceptibility area and each rainfall interval

[0045] According to the results of S1 and S3, count the number of the basin units belonging to each prone area and falling into each rainfall range. This step involves spatial statistical analysis and can be implemented through the spatial analysis module of GIS software.

[0046] S5. Count the number of basin units with geological disasters in each prone area and each rainfall range in the study area

[0047] According to the results of S2 and S3, count the number of basin units with geological disasters belonging to each prone area and each rainfall range. This helps to identify high-risk areas of geological disasters and provides a basis for disaster prevention and control.

[0048] S6. Calculate the occurrence probability of geological disasters in each prone area and each rainfall range

[0049] According to the statistical results of S5 and S4, divide the number of basin units with geological disasters in each range by the number of basin units in the corresponding range to obtain the occurrence probability of geological disasters in different susceptibility situations and different rainfall situations in each range. The specific calculation formula is as follows:

[0050]

[0051] In the formula, u represents the u-th prone area among U prone areas, u ranges from 1 to U, and U is 4 in this embodiment; v represents the v-th rainfall range among V rainfall ranges, v ranges from 1 to V; P uv represents the occurrence probability of geological disasters of the basin units in the u-th prone area and the v-th rainfall range; n uv represents the number of basin units with geological disasters in the u-th prone area and the v-th rainfall range; N uv represents the number of basin units in the u-th prone area and the v-th rainfall range.

[0052] S7. Determination of warning levels

[0053] According to the probability calculation results of S6, based on the interval to which the probability value belongs, divide the warning levels into red warning (0.8 ≤ probability value ≤ 1), orange warning (0.6 ≤ probability value < 0.8), yellow warning (0.4 ≤ probability value < 0.6), blue warning (0.2 ≤ probability value < 0.4), and no warning (0 ≤ probability value < 0.2) levels.

[0054] The present invention integrates data of past extreme rainfall events to establish a simplified method for meteorological risk warning of geological disasters based on basin units, enabling the warning model to not only consider the dynamic changes of rainfall but also make the data processing process more concise and clear; rainfall is one of the main triggering factors for geological disasters, and the integration of dynamic rainfall data significantly improves the timeliness and accuracy of warning.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simplified method for meteorological risk early warning of geological disasters based on watershed units, characterized in that, It includes the following steps: S1. Geological hazard susceptibility zoning for all watershed units in the study area; S2. Obtaining the number and distribution of watershed units with geological disasters in the study area; S3. Obtaining the rainfall values of all watershed units in the study area and dividing the rainfall intervals; S4. Counting the numbers U and V of all watershed units in the study area in each susceptibility area and each rainfall interval; S5. Counting the number of watershed units with geological disasters in each susceptibility area and each rainfall interval in the study area; S6. Calculating the occurrence probability of geological disasters in each susceptibility area and each rainfall interval; S7. Dividing the warning levels according to the probability values.

2. The simplified method for meteorological risk warning of geological disasters based on watershed units as described in claim 1, wherein: Step S1 specifically includes: According to the collected geological hazard data in the study area and the distribution data of its influencing factors, extracting the influencing factors to each watershed unit in the study area, then selecting a model to calculate the susceptibility value, and dividing it into U susceptibility areas by the natural breakpoint method according to the size of the susceptibility value.

3. The simplified method for meteorological risk early warning of geological disasters based on watershed units as described in claim 2, characterized in that: In step S1, an information amount model is used to quantify the influencing factors and calculate the geological hazard susceptibility value of each watershed unit. Assuming that I influencing factors are selected, each influencing factor is divided into J levels according to the size or type of its own value, and the study area is divided into Y watershed units in total; then the susceptibility value calculation formula is as follows: Q y = ∑X yij , wherein, i represents the i-th influencing factor, i ranges from 1 to I; j represents the j-th level of the i-th influencing factor, j ranges from 1 to J; y represents the y-th watershed unit, y ranges from 1 to Y; X yij represents the information quantity value of the y-th watershed unit in the study area for the j-th level of the i-th influencing factor; H represents the total area of the watershed units with geological disasters in the study area; H ij represents the total area of the watershed units with geological disasters in the study area for the j-th level of the i-th influencing factor; when there is no geological disaster, H ij is assigned a value of 0.001; A represents the total area of all watershed units in the study area, that is, the area of the study area; A ij represents the total area of the watershed units at the j-th level of the i-th influencing factor in the study area; Q y represents the information quantity value, that is, the susceptibility value, of the y-th watershed unit when there are I influencing factors each divided into J levels. According to this method, the susceptibility values of the Y watershed units in the study area are calculated.

4. The simplified method for meteorological risk warning of geological disasters based on watershed units as described in claim 1, characterized in that: Step S2 specifically includes: According to the spatial distribution of geological disasters, determining the watershed units to which each geological disaster belongs, conducting spatial analysis through GIS technology, identifying the corresponding relationship between geological disaster points and watershed units, and obtaining the number and distribution of watershed units with geological disasters in the study area.

5. The simplified method for meteorological risk warning of geological disasters based on watershed units as described in claim 1, characterized in that: Step S3 specifically includes: According to the coordinates of each meteorological station and the rainfall gauge record data, after screening, using Kriging method to interpolate the rainfall data, and then assigning the average rainfall value to the Y watershed units in the study area, and dividing the rainfall into V rainfall intervals.

6. The simplified method for meteorological risk early warning of geological disasters based on watershed units as described in claim 1, wherein: In step S6, the calculation method is to divide the number of watershed units with geological disasters in each susceptibility area by the number of watershed units in the corresponding interval.

7. The simplified method for meteorological risk warning of geological disasters based on watershed units as described in claim 1, wherein: The specific calculation formula in step S6 is as follows: Wherein, u represents the u-th prone area among U prone areas, and u ranges from 1 to U; v represents the v-th rainfall interval among V rainfall intervals, and v ranges from 1 to V; P uv represents the probability of geological disasters occurring in the watershed unit in the u-th prone area and the v-th rainfall interval; n uv represents the number of watershed units with geological disasters occurring in the u-th prone area and the v-th rainfall interval; N uv represents the number of watershed units in the u-th prone area and the v-th rainfall interval.

8. The simplified method for meteorological risk warning of geological disasters based on watershed units as described in claim 7, characterized in that: In step S7, the warning levels are divided into red warning, orange warning, yellow warning, blue warning and no warning level.

9. The simplified method for meteorological risk warning of geological disasters based on watershed units as described in claim 8, wherein: In step S7, when 0.8 ≤ P uv ≤ 1, it is the red warning level; when 0.6 ≤ P uv <0.8, it is the orange warning level; 0.4 ≤ P uv <0.6, it is the yellow warning level; 0.2 ≤ P uv <0.4, it is the blue warning level; 0 ≤ P uv <0.2, it is the no-warning level.

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