## 3 Study Area and Data
### Database Preparation and Analysis
(1) Terrain and landform factor: From Figure 4a and Table 1, it is evident that when the elevation is between 400 and 1000 m, the \(FR\) value is greater than 1. This indicates that there are differences in human activities and engineering construction intensity in different elevation areas, leading to significant differences in the disturbance experienced by slopes [27,28]. Landslides in the western Henan area mainly occur in the 0\({}^{\circ}\)-30\({}^{\circ}\) range, especially in the slope range of 10\({}^{\circ}\)-30\({}^{\circ}\), which is more prone to landslide formation. Slope is considered a critical condition for landslide initiation. Slopes that are too gentle cannot provide enough driving force, while slopes that are too steep are not conducive to the accumulation of slope materials, thus failing to provide sufficient material basis for landslides [29,30]. In addition, the aspect influences the distribution of solar radiation intensity and rainfall on slopes [31]. The study results indicate that southeast, south, and southwest aspects significantly influence the formation of landslides in the region. Profile curvature, derived from slope calculation, represents the rate of change of ground elevation along the direction of maximum slope descent. It affects the speed of movement of landslide material and rainfall runoff, thus having an important influence on the spatial distribution and stock of landslide sources. In general, when the profile curvature is greater than 0, landslides are more likely to occur. (2) Basic geological factors and land cover factor: Lithology, as an indispensable material basis in the development of various geological disasters, plays a fundamental controlling role in the development of landslides. Among them, the lithology of the largest area and the most concentrated landslide distribution is mainly composed of intermediate-acidic volcanic rocks such as andesite and andesite basalt, with small amounts of rhyolite and volcanic clastic rocks. The lithology of the second largest distribution includes shale, sandstone, limestone, and dolomite. The lithology of the third most abundant distribution of landslides mainly consists of clay, silt clay, and claye loam, with sub-clayey loamy paleosols at the bottom, accounting for 34.87% of the area and 41.25% of landslides. The fault structures in the geological body play a decisive role in the development of joint fissures. These fissures cause the rock mass to be segmented or fragmented, thereby damaging the stability of slopes. Regarding the distance from faults, the study divides it into nine buffer zones and finds that landslides are more pronounced within 1000 m of faults, showing the highest \(FR\) value. It can be seen that the proximity of faults plays a certain promoting role in landslide formation. In addition, different land use types have varying degrees of impact on landslide occurrence. Figure 4e shows that land use in the study area is classified into seven categories. When land use types are cropland and grassland, \(FR\) values are greater than 1, indicating a higher susceptibility to landslides. (3) Hydroological environmental factors: The topographic wetness index (TWI) is considered as a composite topographic index used to assess the spatial distribution of soil moisture and to quantitatively simulate the wetness conditions of terrain and soil moisture within a watershed [32]. The TWI in the study area is divided into six levels: <5, 5-7.5, 7.5-10, 10-12.5, 12.5-15, and >15. In the western Henan region, the TWI in most areas is less than 10. It is worth noting that in areas where TWI ranges from 5 to 10, the corresponding \(FR\) values are less than 1, indicating that these areas are relatively unfavorable for landslide development. Rivers in the western Henan region were extracted, and buffers were created at 500 m intervals. It was observed that areas within 2000 m of rivers generally exhibited \(FR\) values greater than 1. Among them, areas within 500 m of rivers showed the highest \(FR\) values, reaching 1.411.