GIS-based Analysis of Distribution and Development Characteristics of Landslide Hazards in the Bailong River Basin

Abstract

The Bailong River Basin is one of the most landslide prone areas in China. Based on landslide interpretations from field investigations and high-precision remote sensing images, the influencing factors, distribution rules, and development characteristics of landslides in this region are examined using the powerful spatial analysis capability of the ArcGIS platform. This study identifies the following major influencing factors and provides corresponding conclusions. (1) Fault and tectonic activities: landslides in the study area are distributed mainly in the vicinity of the large and secondary fault zones (< 10 km) and in areas with high peak acceleration and seismic intensity (with a peak motion acceleration of 0.3 g and seismic intensity of a VIII-degree area). (2) Hydrological conditions: the closer to the river (an area of < 200 m), the higher the likelihood of a landslide to occur. Landslide density is highest in areas with substantial short-term rainfall (maximum rainfall amount within 30 min shows the highest correlation with landslides). (3) Topographic parameters of slopes: landslides are distributed mostly on sunny slopes (facing south, southwest, and southeast), gentle slopes (with an incline of approximately 15°–30°), and high mountain areas (with an elevation of approximately 1000–2000 m). (4) Vegetation: areas with low FC coverage (approximately 10%–45%) are prone to landslides, which are distributed mainly in grasslands and cultivated lands. (5) Human engineering activities: densely populated areas (urban areas) and both sides of roads (approximately 0–200 m from a road) are prone to landslides. Overall, landslides are sudden, periodic, synchronous, and occur in groups. The research results have certain reference value for hazard prevention and mitigation in the Bailong River Basin area.