Characteristics of Land Use Change and Its Influencing Factors in Karst Plateau Ecologically Fragile Areas

Land use change is crucial for determining the environmental impact of land conversions and regional development direction. Taking Ceheng County, Guizhou as an example, by selecting multiphase remote sensing data during 2010-2019, combined with demographic and economic data, this study analyzed the characteristics of land-use changes in deeply impoverished karst areas and revealed the mechanism of population and economic development on land use changes in these areas. The results showed that the land use in Ceheng County was dominated by forest land, and Shuangjiang, Badu and Yangba towns had the highest proportions. From 2010 to 2019, there was a decrease in cultivated land and grassland and an increase in construction land and forest land. Cultivated land was the core type of land use change in Ceheng, and its conversion accounted for 66.05% of the total conversions. During 2010-2013 and 2013-2016, cultivated land was mainly converted to construction land, while from 2016 to 2019, it was mainly converted to forest land. The land use changes in Ceheng County mainly occurred in Pomei, downtown, Qiaoma, Rongdu, Yata and Baikou, and there were differences in the changing periods among different towns. No conversion of forest land to cultivated land was found downtown. The economy of Ceheng County showed basically positive growth, while there was negative growth in population and industrial enterprises. Further analysis demonstrated that the conversions of cultivated land to grassland, forest land, other lands and garden land all had significantly positive correlations with the secondary industry and industry (P<0.05). The conversion of grassland to cultivated land presented a significantly positive correlation with population (P<0.05). Therefore, it is necessary to integrate the impacts of factors such as population, economy, natural conditions and national policies on land use patterns, so as to promote the development and ecological environment security of impoverished karst areas.