[Land use changes and driving forces of landslide area in Tongwei County, Gansu Province, Northwest China from 1985 to 2020.]

Abstract

Accurately analyzing the type of land use and change characteristics of disaster damage in landslide areas is of great significance to scientifically promote the optimization of regional land use pattern and disaster prevention and mitigation. We analyzed the characteristic parameters of landslides as well as the characteristics and driving factors of land use change from 1985 to 2020 in Tongwei County, Gansu Province, using ALOS DEM data and 1985-2020 land use data, GIS spatial analysis, land-use dynamic attitude, transfer matrix, and Geodetector. The results showed that a total of 1012 landslide samples were identified, characterized by medium elevation, gentle gradient, low elevation difference, short length, and small size. During 1985-2020, landslide area land use types were cropland, woodland, grassland, bare land and impervious surface, dominated by grassland and cropland. During 2015-2020, each category of single land use dynamic attitude reached the largest, with the value of cropland, grassland, woodland, bare land, and the combined land use being 3.1%, 3.0%, 10.9%, 20.0%, 1.5%, respectively. During the study period, land use change was dominated by cropland and grassland, with a total reduction of 4.39 km² in cultivated land area, which was converted into grassland and forest. There was no change in bare land and impervious surfaces. We investigated the driving factors of land use change across 2000-2005 and 2015-2020. Slope and normalized difference vegetation index had a stronger explanatory power for land use change during 2000-2005, while slope, population density and total population had a stronger explanatory power during 2015-2020. The land use mode of regional individual landslide tended to be unified, and the increase of grassland enhanced the vegetation cover of the region. The findings would provide a scientific basis for the development and reuse of disaster damaged land and ecological restoration.