Spatial Distribution and its Control Factors of Landslides in Longxi County, Gansu Province, China

Abstract

In this study, landslides in the entire Longxi County, Gansu, located in the western part of China’s Loess Plateau, were interpreted using high-resolution optical remote sensing images from the Google Earth platform. A comprehensive and detailed landslide distribution map was prepared, which includes 3,741 landslides. Six factors, including elevation, slope, aspect, slope position, distance to fault, and lithology, were selected to examine their controls to the landslides in the study area. The findings show that the area between 1800 and 1900 m above sea level has a high incidence of landslides. The largest number of landslides was observed within the range of slope 15°–20°. Slopes facing south are more prone to sliding. The lower and middle belts of the slopes show higher landslide susceptibility. The number and area of landslides initially increased, then decrease as the distance to the fault increases. The Cenozoic strata, especially the regions covered by Quaternary sandy loess and the Tertiary sandy mudstone, are the main areas where landslides occur. The results would be helpful in the prevention and mitigation of landslide hazards and disaster relief.