Analysis of Water Quality Evolution and Its Influence Factor in Qingdao Inshore Area

Qingdao is a representative coastal city, whose inshore water quality is in a deterioration tendency influenced by anthropogenic activities. Recent evolution of water quality was quantitatively analyzed by adopting fuzzy comprehensive evaluation method, and its predominant influence factors were determined by a multi-regression model. The results show that: (1)Qingdao inshore water quality worsened from 1998 to 2000, became the worst in 2000, gradually improved from 2000 to 2002, but presented a slight deterioration tendency from 2002. (2)Total discharge amount of waste water, pollutant discharge amount, environmental protection investment and industrial structure were the four remarkable factors affecting Qingdao inshore water quality, among which pollutant discharge amount played the most important role. It is the key of improving water quality to reduce the pollutant discharge amount.