Research on Spatial-temporal Distribution and Impact factors of the Water Quality of the minor Watershed in the South Hill of Hubei Province

Water quality of Gan river from 2000 to 2006 is evaluated by principal component analysis, the results show that in the past 7 years, on the whole, the water quality of Gan river is getting better, but the water quality of Gan river in middle and lower reaches is still poorer. Water quality improvement lies in the mass decrease of industrial wastewater, but life sewage and agricultural pollution are yet still expanding. In order to control Gan river and improve river environment, Some suggestions are proposed.