Abstract: Based on remote sensing and correlation analysis, this paper examined the relationships between land-use change and lake water quality in Fuxian and Qilu basins of Yunnan Province in 1989-2005. The results showed that in the two basins, forest/shrub land and construction-use land increased largely, while unused and crop lands had somewhat decrease. Qilu Lake was more heavily polluted than Fuxian Lake, and the water quality of the two lakes became worse. The impact of land-use change on lake water quality was more obvious in a 200 m buffer zone around the lakes. Urbanization and intensive farming were the two major factors causing the continued degradation of lake water quality, and the difference in land use structure between the two basins also resulted in the difference in water quality of the two lakes.

Key words: Dryland, Apple orchard, Desiccation, Nitrate accumulation