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.
准确分析滑坡区灾损土地利用类型及变化特征,对科学推进区域土地利用格局优化和防灾减灾具有重要意义。利用ALOS DEM数据和1985—2020年土地利用数据,采用GIS空间分析、土地利用动态度、转移矩阵及地理探测器,分析甘肃省通渭县滑坡的特征参数和1985—2020年土地利用变化特征及驱动因素。结果表明: 本研究共识别出1012个滑坡样本,具有中海拔、缓坡度、低高差、短长度、小规模的特征。1985—2020年,滑坡区土地利用类型为耕地、林地、草地、裸地和不透水表面,以草地和耕地为主;2015—2020年,各地类单一土地利用动态度在研究期间均最大,耕地3.1%、草地3.0%、林地10.9%、裸地20.0%,综合土地利用动态度为1.5%。研究期间,土地利用变化以耕地和草地为主,耕地面积共减少4.39 km2,转为草地和林地;裸地和不透水表面无变化。选取2000—2005和2015—2020年2个时段探究土地利用变化的主要驱动力。2000—2005年,坡度和归一化植被指数对土地利用变化的解释力较强,2015—2020年,坡度、人口密度和总人口的解释力较强。区域单个滑体的土地利用方式趋于统一化,草地的增加提升了区域的植被覆盖度。研究结果可为灾损土地的开发再利用及生态修复提供科学依据。.
Keywords: land-use dynamic attitude; Geodetector; Tongwei County; land use change; landslide.