Impact of land use change on water quality in the Dianchi Lake watershed, Yunnan, China, 1988-2008

Land use changes occurring in China during the time period of rapid economic development are linked to the degradation of water quality in streams and lakes. This paper examines these linkages in the Dianchi Lake watershed in Yunnan in southwest China based on a twenty-year data set from 1988 to 2008. Pearson correlation analysis and simple linear regression analysis are employed to explore the relationships between land use change and water quality of two sub-basins, the Caohai Lake basin and the Waihai Lake basin, within the Dianchi Lake watershed. Land use categories more strongly correlate to water quality in the Caohai Lake basin than that in the Waihai Lake basin. The different structure of land use categories, spatial distribution of land cover, and scales of buffer zones could be the factors resulting in the dissimilarities between these two lakes. The research can provide valuable insights for policymakers into land use management in order to curb further water degradation in Dianchi Lake.