Refined rainfall threshold zoning method based on landslide type zoning

Abstract

The invention relates to the technical field of geological disaster prediction and forecast, in particular to a refined rainfall threshold zoning method based on landslide type zoning. The method comprises the following steps: acquiring a landslide list, rainfall data, literature data, stratum lithology and landform data of a research area; based on the landslide list, the rainfall data, the literature data, the stratum lithology and the landform data, the landslide type of the research area is obtained through analysis; according to the landslide list, the stratum lithology and the field investigation preliminary subareas, determining development subareas of various types of landslides; based on the development characteristics of various landslides, comprehensively considering lithology, gradient, vegetation coverage and fault density to determine rainfall threshold partitions; and according to the rainfall data, a refined rainfall threshold value of each partition is obtained based on a rainfall threshold value model. According to the method, the problem of differential response of different landslide types to rainfall is solved, so that a more reliable refined rainfall threshold is obtained, and the precision of the rainfall threshold is improved.

Description

Technical Field

[0001] The invention relates to the technical field of geological disaster prediction and forecasting, and in particular to a refined rainfall threshold zoning method based on landslide type zoning. Background Art

[0002] The rainfall threshold usually refers to the critical rainfall when a geological disaster causes instability. It is the basis for establishing meteorological warnings for geological disasters. The accuracy of the rainfall threshold directly affects the accuracy of the warning results. In the past decade, geological disaster prediction and forecasting has become a research hotspot. A large number of scholars at home and abroad have carried out research work related to rainfall thresholds, and have widely applied them in geological disaster risk prevention and control.

[0003] At present, regional early warning models often use a set of rainfall thresholds for early warning, without distinguishing between landslide types. However, the response of different landslide types to rainfall varies significantly. For example, soil landslides have a loose structure and many voids in the slope. Rock landslides have a denser structure and higher mechanical strength. After rainfall, rainwater can quickly infiltrate soil landslides, and the slopes are quickly destroyed, while rock landslides may require greater rainfall to induce instability. Therefore, the rainfall thresholds for different types of landslides are different. It is necessary to divide them into zones according to the type of landslide, and then calculate the refined rainfall thresholds for different regions, thereby improving the accuracy of rainfall thresholds and improving the reliability and accuracy of predictions and forecasts. Summary of the invention

[0004] In order to solve the problem of low regional rainfall threshold accuracy and differential response of different landslide types to rainfall pointed out in the background technology, the present invention provides a refined rainfall threshold partitioning method based on landslide type partitioning, which obtains a more reliable refined rainfall threshold and improves the accuracy of the rainfall threshold. The method mainly includes the following steps:

[0005] S1: Obtain the landslide inventory, rainfall data, literature, stratigraphic lithology and topographic data of the study area;

[0006] S2: Based on the landslide inventory, rainfall data, literature, stratigraphic lithology and topographic data, the landslide types in the study area were analyzed;

[0007] S3: Determine the development zones of various types of landslides based on the landslide inventory, stratum lithology and preliminary zoning by field investigation;

[0008] S4: Based on the development characteristics of various landslides, the rainfall threshold zoning is determined by comprehensively considering lithology, slope, vegetation cover and fault density;

[0009] S5: According to the actually obtained rainfall data, a refined rainfall threshold for each partition is obtained based on a rainfall threshold model.

[0010] A computer device comprises a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above method.

[0011] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the above method.

[0012] A computer program product comprises a computer program or instructions, and when the program or instructions are executed by a processor, the steps of the above method are implemented.

[0013] The beneficial effect brought about by the technical solution provided by the present invention is: the refined rainfall threshold zoning method based on landslide type zoning proposed by the present invention solves the problem of differential response of different landslide types to rainfall, thereby obtaining a more reliable refined rainfall threshold and improving the accuracy of the rainfall threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0015] Figure 1 It is a flow chart of a refined rainfall threshold zoning method based on landslide type zoning in an embodiment of the present invention;

[0016] Figure 2 is a disaster distribution map of the study area in an embodiment of the present invention;

[0017] Figure 3 is a distribution map of engineering rock formations in the study area in the embodiment of the present invention;

[0018] Figure 4 is a distribution map of different types of landslide development zones in the study area in the embodiment of the present invention;

[0019] Figure 5 is a slope distribution map of the study area in an embodiment of the present invention;

[0020] Figure 6 is a vegetation coverage distribution map of the study area in the embodiment of the present invention;

[0021] Figure 7 is a fault density distribution map of the study area in the embodiment of the present invention;

[0022] Figure 8 This is a result diagram of the refined rainfall threshold zoning of the study area in an embodiment of the present invention;

[0023] Fig. 9 is a rainfall threshold map for each subarea in an embodiment of the present invention;

[0024] Fig.10It is a diagram of the meteorological risk warning results of geological disasters in Hubei Province on July 1, 2016 in an embodiment of the present invention;

[0025] Fig.11 It is a diagram of the meteorological risk warning results of geological disasters in Hubei Province on July 2, 2016 in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0027] Example 1

[0028] Please refer to Figure 1 , Figure 1 1 is a flow chart of a method for fine-grained rainfall threshold zoning based on landslide type zoning in an embodiment of the present invention, which specifically includes:

[0029] S1: Obtain the landslide inventory, rainfall data, literature, stratigraphic lithology and topographic data of the study area;

[0030] S2: Based on the landslide inventory, rainfall data, literature, stratigraphic lithology and topographic data, the landslide types in the study area were analyzed;

[0031] S3: According to the landslide list, stratum lithology and preliminary zoning of field investigation, determine the development zoning of each type of landslide; in this step, the analysis of landslide types needs to be combined with the landslide list, field investigation, engineering rock group and weathering degree. First, confirm the spatial location of the landslide according to the landslide list, and then judge whether a certain area is mainly soil or rock according to the engineering rock group. For example, if the material composition of the area is mainly soil, then the type of landslide in the area is judged to be soil landslide, and the preliminary development zoning results of different landslide types are obtained. Finally, conduct a field investigation to verify the landslide type in the area.

[0032] S4: Based on the development characteristics of various landslides, the rainfall threshold zones are determined by comprehensively considering the lithology, slope, vegetation coverage and fault density; the rainfall threshold zone values ​​will change according to the different environments of the study area. The rainfall threshold zones include: (1) soil-rock mixed landslides, rock-soil mixed landslides and rock landslides: the vegetation coverage rate is within the first interval, the highest terrain undulation is the first set value, the median slope is the first set slope, and the fault density range is within the first density space; (2) soil-rock mixed landslides and rock landslides: the vegetation coverage rate is within the second interval, the highest terrain undulation is the second set value, the median slope is the second set slope, and the fault density range is within the second density interval; (3) soil-rock mixed landslides and soil landslides: the vegetation coverage rate is within the third interval, the highest terrain undulation is the third set value, the median slope is the third set slope, and the fault density range is within the third density interval. The range of density of faults is within the third density interval; (4) rock-soil mixed landslide and rock landslide: the range of vegetation coverage is within the fourth interval, the highest terrain undulation is the fourth set value, the median slope is the fourth set slope, and the range of fault density is within the fourth density interval; (5) soil-rock mixed landslide and rock-soil mixed landslide: the range of vegetation coverage is within the fifth interval, the highest terrain undulation is the fifth set value, the median slope is the fifth set slope, and the range of fault density is within the fifth density interval; (6) soil landslide: the range of vegetation coverage is within the sixth interval, the average value of terrain undulation is the sixth set value, the average value of slope is the sixth set slope, and the range of fault density is within the sixth density interval.

[0033] S5: According to the actually acquired rainfall data, the refined rainfall thresholds of each subarea divided according to the landslide type in S2 are obtained based on the rainfall threshold model. The rainfall threshold model is one of the Rd-Rp, ED, ID and other models.

[0034] Due to the complex development of geological disasters, a region often has multiple types of landslides. The initial development zones of different landslide types are relatively scattered and not concentrated enough, which is not conducive to rainfall threshold statistics. Therefore, in S4, the initial zones of different landslide types obtained in S3 are further considered based on the results of the preliminary zones, such as undulation, vegetation coverage, fault density, etc., to further optimize the zone boundaries. The final rainfall threshold zones are determined to facilitate regional early warning and administrative management.

[0035] The present invention uses the heavy rainfall event that occurred on July 1-2, 2016 as an example to verify the reliability of the refined rainfall threshold. Specifically, the study area in this example is a certain area, such as Hubei Province, China. Collect landslide list: As of November 2024, through the sorting of geological disaster data such as detailed geological disaster investigation, geological disaster risk investigation and evaluation, detailed geological disaster investigation in key areas, geological disaster investigation (exploration) in towns and other special investigation projects, there are a total of 16,458 geological disasters and potential hazards in Hubei Province, such as Figure 2 As shown, there are 13903 landslides and potential hazards, accounting for 84.48% of the total number of geological disasters; 1937 collapses and potential hazards, accounting for 11.77% of the total number of geological disasters; 467 ground subsidence and potential hazards, accounting for 2.84% of the total number of geological disasters; 151 debris flows and potential hazards, accounting for 0.92% of the total number of geological disasters. Collecting rainfall data: National ground meteorological observation stations are usually located in representative locations across the country. The distance between stations is relatively far, but the observation projects are relatively comprehensive, high-standard observation equipment is used, and the degree of automation of data collection and processing is high, ensuring the accuracy and continuity of the observation data. Township meteorological observation stations are more densely set up to obtain detailed meteorological change information in the area. Therefore, the rainfall data studied in this embodiment mainly comes from 53 national rainfall stations in Hubei Province, supplemented by township rainfall stations, among which all national stations are ground meteorological observation stations that mainly observe basic meteorological elements such as rainfall, temperature, humidity, wind direction, and wind speed. The data recording time of the observation station is from 1970 to 2023. The data types include hourly rainfall and daily rainfall, and the data are accurate to 0.1mm. Collect stratigraphic lithology data: There are 19 engineering rock groups in the whole area. The spatial distribution of engineering rock groups in the study area is as follows: Figure 3 The specific description of each type of engineering rock group is shown in Table 1. From the perspective of geological disaster development density, the distribution area of ​​carbonate engineering geological rock type distribution area where the parent rock is quartz sandstone interlayer lithology group in the material composition of the disaster body is the engineering geological rock group distribution area with the highest disaster density in the province, with a disaster point density of 0.308 places / km2; followed by the distribution area where the parent rock is muddy carbonate rock and soft shale mudstone siltstone interlayer lithology group, with a disaster point density of 0.196 places / km2. The distribution area of ​​metamorphic rock engineering geological rock type distribution area where the parent rock is metavolcanic rock group in the material composition of the disaster body has the largest density, with a disaster point density of 0.199 places / km2; followed by the distribution area of ​​meta-sedimentary rock lithology group, with a disaster point density of 0.0.175 places / km2. In the distribution area of ​​clastic rock engineering geological rock type, the geological disaster density is the highest in the distribution area where the parent rock of the disaster body material composition is sandstone intercalated with soft shale mudstone conglomerate lithology group, with a disaster point density of 0.317 places / km2, followed by the distribution area of ​​quartz sandstone lithology group, with a disaster point density of 0.208 places / km2, and then the distribution area of ​​sandstone mudstone limestone lithology group, with a disaster point density of 0.178 places / km2; in the distribution area of ​​igneous rock engineering geological rock type, the disaster density is the highest in the distribution area where the parent rock of the disaster body material composition is volcanic rock group, with a disaster point density of 0.144 places / km2; in the provincial regional soil distribution area, due to the flat terrain, the disaster point density is only 0.021~0.043 places / km2.

[0036] Table 1 Classification of stratum lithology and landslide types

[0037]

[0038]

[0039] Classification of landslide types: The development of landslides is controlled by the lithology of the strata. According to the material composition of the landslide body, it can be divided into four types of landslides (Table 1): (1) Soil landslides, where more than 80% of the main material of the landslide is soil; (2) Rock landslides, where more than 80% of the main material of the landslide is rock; (3) Soil-rock mixed landslides, where soil and rock account for an equal proportion in the landslide material composition, and the soil content is higher. (4) Rock-soil mixed landslides, where soil and rock account for an equal proportion in the landslide material composition, but the rock content is higher. The Quaternary loose rock type is mainly loose and plastic gravel soil, so soil landslides are mainly developed. Metamorphic rocks are mainly gneiss and quartzite, and the rock properties are hard, so rock landslides are mainly developed. Sedimentary rocks are mainly shale and mudstone with some limestone, with soil accounting for the majority and some rock, so soil-rock mixed landslides are mainly developed. Granite is mainly gabbro, but according to literature and field investigation, the weathering degree is high, and the surface layer is completely weathered into soil, so the main landslide type is rock-soil mixed landslide. According to the properties of rock and soil in the engineering rock group, four types of stratum lithology are summarized, and then the main landslide types in each type of lithology are analyzed to obtain preliminary development zoning results of different landslide types, such as Figure 4 However, these zonings are too fragmented and each type of zoning is not independent enough, so it is necessary to further analyze the characteristics of landslides and then classify and integrate them to facilitate subsequent early warning and administrative management after early warning.

[0040] Hubei Province has various landslide types and complex topography. This natural feature has a profound impact on the type and development of geological disasters, showing distinct regional differences. In order to obtain a high-precision rainfall threshold, the province is divided into six rainfall threshold zones based on landslide types and geomorphological features, and the distribution law of geological disaster development in each zone is analyzed in detail. Specifically, the distribution of geological disasters and hidden dangers in Hubei Province shows an obvious trend of gradually decreasing from the west, north, and south to the central part. According to the number of geological disasters and hidden dangers, the ranking of each zone is: Northwest Hubei, Southwest Hubei, Northeast Hubei, Southeast Hubei, North Hubei and Jianghan Plain. The low mountains and low and medium mountainous areas in southwestern Hubei are the areas with the most concentrated geological disasters, with a total of 8,212 geological disasters, accounting for 49.9% of the total number of geological disasters and hidden dangers in the province, becoming the "hardest hit area" of geological disasters. Following closely are the low mountains and medium mountainous areas in northwestern Hubei, with a total of 5,200 geological disasters and hidden dangers, accounting for 31.6%. The low mountains and hilly areas in northeastern Hubei ranked third, with a total of 1,348 geological disasters and potential hazards, accounting for 8.19% of the total number in the province. The three geomorphic divisions combined accounted for 89.68% of geological disasters, which fully demonstrated that southwestern and northwestern Hubei are high-incidence areas of geological disasters in Hubei Province. In contrast, the development level of geological disasters in the Jianghan Plain area is relatively low, with only 270 geological disasters and potential hazards, accounting for only 1.64% of the total number in the province. This data clearly reflects that different landslide types have a significant control effect on the type and number of geological disasters and potential hazards. The development characteristics of geological disasters in each division are not only closely related to the complexity of the topography and landforms, but also affected by multiple factors such as vegetation coverage. Figure 5 is the slope distribution map of the study area in the embodiment of the present invention, Figure 6 is a vegetation coverage distribution map of the study area in the embodiment of the present invention, Figure 7 is a fault density distribution map of the study area in the embodiment of the present invention; Figure 8 This is the result map of the refined rainfall threshold zoning of the study area in the embodiment of the present invention. Therefore, in the prevention and control of geological disasters, it is necessary to fully consider the differences in landslide types and formulate targeted prevention and control measures to effectively reduce the risk and degree of damage of geological disasters. Based on the development characteristics of various types of landslides, this embodiment comprehensively considers lithology, slope, vegetation coverage and fault density to determine the rainfall threshold zoning. The specific contents are as follows:

[0041] (I) Low mountains and low-middle mountain areas in southwestern Hubei

[0042] The low mountains and middle mountains in southwestern Hubei, as the area with the most developed geological disasters in Hubei Province, have a total of 8,212 geological disasters, accounting for 49.89% of the total number of geological disasters in the province.

[0043] The slippery strata in the area are mostly controlled by soft rock interlayers, such as the lithological combination of soft thin to medium-thick sandstone mudstone shale interlayered with thin and medium-thick sandstone mudstone limestone in the Silurian (S) and the middle and upper Ordovician (O2-3), and the lithological combination of relatively hard thin to medium-thick weakly karstified muddy carbonate rock and soft shale mudstone siltstone interlayer in the Lower Cambrian (∈1), the middle and upper Devonian (D2-3), and the Badong Formation (T2b) of the Middle Triassic. The soft rock interlayers in these stratigraphic combinations often become the key controlling factors for the occurrence of geological disasters such as landslides.

[0044] The landslide types in this area are: soil-rock mixed landslide, rock-soil mixed landslide and rock landslide. The vegetation coverage rate is relatively high, ranging from 0.75-1. The terrain is undulating, with the highest undulation of 757m. The slope is steep, with a median of 36.5°. The fault density is relatively high in the north, reaching above 0.7.

[0045] (II) Low and middle mountain areas in northwestern Hubei

[0046] There are 5,200 geological disasters in the low and middle mountainous areas of northwestern Hubei, accounting for 31.6% of the total number of geological disasters in the province. Landslides are the most developed in the area, with 4,952 landslides.

[0047] The soft rock systems such as slate, phyllite, and schist, which are widely distributed in the low mountains and middle mountains of northwestern Hubei, constitute the main geological background for the occurrence of geological disasters in the region. These soft rock systems have low mechanical strength in general, and the long-term strong surface weathering has formed a unique breeding environment for geological disasters. The fracture structure surface characteristics of soft rocks are significant, manifested as a short and dense fracture network, which is not only conducive to the infiltration of groundwater, but also accelerates the weathering and deformation process of shallow rock mass, providing a rich material basis for the occurrence of geological disasters.

[0048] The landslide types in this area are: soil-rock mixed landslide and rock landslide. The vegetation coverage rate is relatively high, ranging from 0.75-1. The terrain is undulating with a relatively gentle undulation, reaching a maximum of 342m. The slope is relatively gentle with a median of 22.4°. The fault density is relatively high, ranging from 0.85-1.

[0049] (III) Low mountain and hilly areas in northeastern Hubei

[0050] There are 1,348 geological disasters in the region, accounting for 8.19% of the total number of disaster points in the province. The development degree of geological disasters ranks third in the province, mainly landslides, of which there are 1,016 landslides.

[0051] In terms of geological structure, the region mainly develops the Tongbaishan anticline, the Dabieshan anticline and a series of important faults, such as the Yingdian-Qingshankou fault, the Dawu pressure fault, the Luoshui pressure fault and the Matuan fault. These structural features not only reveal the complexity of regional geological evolution, but also affect the development and distribution of metamorphic rock systems in the region. In terms of stratigraphic lithology, the region is dominated by gneiss and schist, accompanied by a large number of granite intrusions. In the southwestern part, it is mainly a set of blue-shimmering-green schist facies to low green schist facies metamorphic rock combinations. These rocks are mainly distributed in the Wudang Group and Yaolinghe Formation of the Nanhua Period. The lithology is mainly slate, schist, phyllite, and metamorphic sandstone, and is interbedded with carbonate rocks and shales of the Cambrian and Sinian systems of the Lower Paleozoic.

[0052] The landslide types in this area are: soil-rock mixed landslide and soil landslide. The vegetation coverage rate is low, ranging from 0.5-0.75. The terrain is relatively flat, reaching a maximum of 84m. The slope is relatively flat, with a median of 12°. The fault density is relatively sparse, ranging from 0-0.4.

[0053] (IV) Low mountain and hilly area in southeastern Hubei

[0054] There are 738 geological disasters in the district, accounting for 4.48% of the total number of disaster points in the province, and the degree of geological disaster development ranks fourth in the province.

[0055] In the southern Tongcheng area, the large-scale distribution of Yanshanian granite, granodiorite and monzogranite constitutes a huge rock matrix. These rocks are hard and resistant to weathering, so only sporadic geological disasters such as small collapses and landslides occur. This is mainly due to the physical and mechanical properties of the rock itself and good geological structural conditions. The area from Chibi to Tongshan in the middle is dominated by layered rock bodies. The geological structure here is relatively complex, with slate, metamorphic sandstone, mudstone, and carbonate rocks widely distributed with sandstone, shale, mudstone and other interlayers of varying thickness.

[0056] The landslide types in this area are: mixed rock-soil landslide and rock landslide. The vegetation coverage rate is low, ranging from 0.68-0.82. The terrain undulation is medium, reaching a maximum of 395m. The slope is medium, with a median of 23.5°. The fault density is relatively dense, ranging from 0.5-1.

[0057] (V) Hilly areas in northern Hubei

[0058] There are only 690 geological disasters in the district, accounting for 4.19% of the total number of disaster points in the province, and the degree of geological disaster development ranks fifth in the province.

[0059] The area is clearly located in the northern part of the Qingfeng-Xiangfan-Guangji fault zone in terms of tectonic position, and is an important part of the Nanxiang superimposed fault basin. In terms of surface coverage, most of the area is covered by alluvial and flood deposits. The upper part of these deposits is mainly composed of clay, silty clay and silt, while the lower part is mainly composed of sand and gravel. Only in the marginal area of ​​the Xiangguang fault in the south can a small amount of slate, phyllite, schist of the Nanhua system, as well as sandstone of the Paleogene and Cretaceous system, as well as interlayers of carbonate rocks, shales and sandstones of the Sinian and Paleozoic systems be seen.

[0060] The landslide types in this area are: soil-rock mixed landslide and rock-soil mixed landslide. The vegetation coverage rate is relatively high, ranging from 0.84-1. The terrain undulation is medium, reaching a maximum of 386m. The slope is medium, with a median of 27.8°. The fault density is medium, ranging from 0.3-0.7.

[0061] (VI) Jianghan Plain

[0062] There are 270 geological disasters in the area, accounting for 1.64% of the total number of disaster points in the province, and the degree of geological disaster development ranks sixth in the province. The area is mainly soil landslides, and the exposed strata are alluvial, flood and lacustrine deposits. The upper part is silty soil, clay, silty clay and silt, and the lower part is sand and gravel.

[0063] The landslide types in this area are: soil landslide, low vegetation coverage, ranging from 0-0.5, flat terrain with almost no undulation, the average terrain undulation is 0.1m, gentle slope, averaging 3°, and very sparse fault density, ranging from 0-0.01.

[0064] Any rainfall threshold model can obtain the rainfall threshold. This embodiment uses the Rd-Rp model for threshold statistics. Its horizontal and vertical coordinates are the previous effective rainfall (Rd) and the rainfall on the day of the landslide (Rp), respectively. Fig. 9 The previous effective rainfall (Rd) and the rainfall on the day of landslide (Rp) can be obtained based on rainfall data statistics. This model believes that the rainfall on the day of landslide has a significant impact on the occurrence of landslides. It does not consider the duration of rainfall and mainly studies the overall impact of effective rainfall on landslides. It is also commonly used in early warning research.

[0065] Finally, the reliability of the refined thresholds of each sub-region is verified through historical heavy rainfall disasters: the red, orange, yellow and blue levels of the rainfall threshold correspond to the red warning, orange warning, yellow warning and blue warning in the warning results. Fig.10 , Fig.11The following are the early warning result maps based on slope units on July 1, 2016 and July 2, 2016, respectively. It can be seen from the comprehensive rainfall distribution map and the early warning result map that there is a good correspondence between the rainfall concentration area in southeastern Hubei and the high warning area, and the occurrence of landslide disasters is mainly based on immediate response. From the distribution of disaster points, the disaster points on July 1 were mainly distributed in Hong'an County, Luotian County, Yingshan County, Tuanfeng County of Huanggang City in eastern Hubei, Jingshan City, Zhongxiang City in central Hubei, etc., where the rainfall was heavy on that day. The disaster points on July 2 were distributed in Wuxue City, Xishui County and other counties in eastern Hubei. The rainfall at the disaster points in eastern Hubei was heavy the day before and on that day, and some of them were landslides induced by heavy rain. Most of the disaster points are distributed in the slope units where yellow and above warnings were issued. Table 2 is a statistical table of early warning results for rainfall-induced landslide events in July 2016, as shown below:

[0066] Table 2 Statistics of early warning results of rainfall landslide events in July 2016

[0067]

[0068] Judging from the warning statistics, the overall warning accuracy of this rainfall process is high, and most of the landslides induced by rainfall are located within the warning area. Among them, the warning accuracy of the yellow warning and above warning areas on July 1 was 86.7%, and the warning accuracy of the yellow warning and above warning areas on July 2 was 91.21%, which showed a good warning effect overall. Some disaster points are distributed in the blue warning area. The main reason is that the rainfall of this rainfall event is extremely large and covers a wide range, involving parts of the Jianghan Plain, thus triggering more landslide disasters in some hilly areas in the plain. From the perspective of the whole province, the susceptibility of these areas is at a lower level, so the corresponding warning level is also low.

[0069] Example 2

[0070] A computer device comprises a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above method.

[0071] Example 3

[0072] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the above method.

[0073] Example 4

[0074] A computer program product comprises a computer program or instructions, and when the program or instructions are executed by a processor, the steps of the above method are implemented.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A refined rainfall threshold zoning method based on landslide type zoning, characterized in that: include: S1: Obtain the landslide inventory, rainfall data, literature, stratigraphic lithology and topographic data of the study area; S2: Based on the landslide inventory, rainfall data, literature, stratigraphic lithology and topographic data, the landslide types in the study area were analyzed; S3: Determine the development zones of various types of landslides based on the landslide inventory, stratum lithology and preliminary zoning by field investigation; S4: Based on the development characteristics of various landslides, the rainfall threshold zoning is determined by comprehensively considering lithology, slope, vegetation cover and fault density; S5: According to the actually obtained rainfall data, a refined rainfall threshold for each partition is obtained based on a rainfall threshold model.

2. A method for fine-grained rainfall threshold zoning based on landslide type zoning according to claim 1, characterized in that: In S1, the landslide list includes information on the time, space and scale of landslides; rainfall data include hourly, daily and monthly rainfall data from national and local rainfall stations; literature includes historical geological disaster surveys, scientific research papers, hydrological surveys, geological explorations and risk surveys in the study area; stratigraphic lithology includes engineering rock groups, geological age and rock properties; topography includes elevation, slope and undulation information.

3. The method for fine-grained rainfall threshold zoning based on landslide type zoning according to claim 1 is characterized in that: In S2, landslide types are divided into soil landslide, rock landslide, soil-rock mixed landslide and rock-soil mixed landslide according to their material composition.

4. A method for fine-grained rainfall threshold zoning based on landslide type zoning according to claim 3, characterized in that: A soil landslide is a landslide in which the soil content of the sliding body is greater than 80%, a rock landslide is a landslide in which the rock content of the sliding body is greater than 80%, a soil-rock mixed landslide is a landslide in which the soil and rock contents in the sliding body are similar, but the soil content is higher than the rock; a rock-soil mixed landslide is a landslide in which the soil and rock contents in the sliding body are similar, but the rock content is higher than the soil.

5. The method for fine-grained rainfall threshold zoning based on landslide type zoning according to claim 1 is characterized in that: In S3, the spatial location of the landslide is first confirmed based on the landslide list, and then the main soil or rock layer in a certain area is determined based on the engineering rock group, and the preliminary development zoning results of different landslide types are obtained.

6. A method for fine-grained rainfall threshold zoning based on landslide type zoning according to claim 1, characterized in that: In S4, the rainfall threshold zoning includes: (1) soil-rock mixed landslide, rock-soil mixed landslide and rock landslide: the vegetation coverage rate is within the first interval, the maximum terrain undulation is the first set value, the median slope is the first set slope, and the fault density is within the first density space; (2) soil-rock mixed landslide and rock landslide: the vegetation coverage rate is within the second interval, the maximum terrain undulation is the second set value, the median slope is the second set slope, and the fault density is within the second density interval; (3) soil-rock mixed landslide and soil landslide: the vegetation coverage rate is within the third interval, the maximum terrain undulation is the third set value, the median slope is the third set slope, and the fault density is within the second density interval. The range of the density of soil-rock mixed landslides and rock landslides is within the third density interval; (4) rock-soil mixed landslides and rock landslides: the range of the vegetation coverage rate is within the fourth interval, the maximum terrain undulation is the fourth set value, the median slope is the fourth set slope, and the range of the fault density is within the fourth density interval; (5) soil-rock mixed landslides and rock-soil mixed landslides: the range of the vegetation coverage rate is within the fifth interval, the maximum terrain undulation is the fifth set value, the median slope is the fifth set slope, and the range of the fault density is within the fifth density interval; (6) soil landslides: the range of the vegetation coverage rate is within the sixth interval, the average value of the terrain undulation is the sixth set value, the average value of the slope is the sixth set slope, and the range of the fault density is within the sixth density interval.

7. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the refined rainfall threshold zoning method based on landslide type zoning as described in any one of claims 2 to 6.

8. A computer-readable storage medium, characterized in that: A computer program is stored, and when the program is executed by a processor, the steps of the refined rainfall threshold zoning method based on landslide type zoning as described in any one of claims 2 to 6 are implemented.

9. A computer program product, characterized in that It comprises a computer program or an instruction, which, when executed by a processor, implements the steps of the method for refined rainfall threshold zoning based on landslide type zoning as described in any one of claims 2 to 6.

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