Impact of land use change on groundwater quality in a typical karst watershed of southwest China: a case study of the Xiaojiang watershed, Yunnan Province

摘要: The impact of land-use change on the quality groundwater in Xiaotjiang watershed, China was assessed for period 1982–2004. Groundwater samples were collected from 30 monitoring points across and representative various changes, determined by remote sensing geographical information systems. results indicate that 610 km2 (60% total watershed area) subject to during period. most important changes conversion 135 km2 forested land cultivated land, 211 km2 unused land. main ascribed diffuse pollution fertilizers applied newly building development. Overall pH value significantly increased, as concentrations ions $$ {\text{NH}}^{ + }_{4} $$ , {\text{SO}}^{{2 - }}_{4} {\text{NO}}^{ }_{3} }_{2} Cl− whilst Ca2+ {\text{HCO}}^{ declined. More precisely, regions where converted into Mg2+, increased However region construction Ca2+, increased.