Evaluation and Analysis of Water Quality at the Dahuofang Reservoir Based on the Fuzzy Evaluation and Analytical Hierarchy Process

Based on the fuzzy mathematics and analytical hierarchy process (AHP), the water quality was evaluated and analyzed according to 7 water pollution factors in 7 monitoring sections at the Dahuofang Reservoir which reflected the water quality at reservoir inflow, in reservoir area, and at reservoir outflow. The results show that: In 2010, the Dahuofang Reservoir was mainly polluted by nitrogen/phosphorus nutrient salts. Among the reservoir inflow, the Hunhe River was the most polluted. The water quality in reservoir area was mainly of Class II; the water quality at reservoir outflow was also of Class II, and was safe and reliable. According to the change of water quality monitoring value at three sections of Hunhe River (#73, #37 and #7) from 2005 - 2010, the pollution in the reservoir area had been effectively controlled, and the water quality in the reservoir area had been steadily improved.