Abstract:
The identification of land use and its topographic gradient patterns and functional zoning are the bases for the sustainable use of land resources and the optimization of land use planning in the Red River Basin. Based on RS and GIS technology, the spatio-temporal variability of land use change in elevations, slopes and topographic position gradients in the Red River Basin of Yunnan Province in 2000, 2010 and 2020 was systematically analyzed, using the topographic distribution index and topographic position index methods. And based on the analysis results, the functional zoning of the Red River Basin was carried out. The results show that: ① Forest land (56.46%) and cultivated land (29.34%) were the main land use types, followed by grassland (6.93%) and shrub land (6.17%) in the Red River Basin; each of the proportions of wetlands, water bodies and artificial land surface was less than 1%. From 2000 to 2020, the cultivated land and artificial land surface in the Red River Basin expanded significantly, while the woodland decreased continuously, showing a phenomenon of woodland being invaded. ② The distributions of land use types in the Red River Basin of Yunnan Province show obvious topographic gradients: the cultivated land and artificial land surface are limited by the difficulty of high topographic development, so their dominant positions are in the middle and low topographic river valley and mountainside areas; the wetland and water bodies are concentrated in the low topography; the grassland and shrub land are concentrated in the middle-low topography; and the woodland is widely distributed in the middle-high topography. ③ Based on the regularities of the topographic differentiation of land use, the Red River Basin of Yunnan Province is divided into four land use functional zones: Valley intensive development zone, steep slope comprehensive management zone, high mountain potential development zone and mountain top ecological regulation zone.