Analysis of the impact on the water quality of Cixi by areas along the north line of water diversion from Cao’e river

The north line of water diversion from Cao’e river is one of the six major water diversion projects in eastern Zhejiang Province. The project passes through three cities of YuYuCi. It mainly supplies water for Industry and agriculture, and takes into account the improvement of water environment. Cixi City is located at the end of the north line of water diversion from Cao’e river, and its water quality is affected by the nodes along the water diversion line. Using the least square method which can extract the main components of the independent variables on the dependent variables, the regression equations of the independent variables: Mushan sluice, Qitang sluice, Sitang sluice, Puqian sluice, xinsanjiang sluice and Luzhongwan pumping station are established, and the contribution values of each node to Luzhongwan pumping station under the indexes of permanganate, ammonia nitrogen, total phosphorus and dissolved oxygen are calculated. The results show that Sitang sluice has the greatest contribution to permanganate and total phosphorus of Luzhongwan pumping station, Puqian sluice has the greatest impact on ammonia nitrogen index of Luzhongwan pumping station, and xinsanjiang sluice has the greatest impact on dissolved oxygen index of Luzhongwan pumping station. Generally speaking, the stations which have the greatest impact on the water quality of Luzhongwan pumping station are Sitang sluice and Qitang sluice.