Research on the response of water quality to human activities in Shuangta Reservoir, Shulehe River Basin

In order to simplify the subsequent analysis, principal component analysis method was used to analysis the human activities and land use changes data in Guazhou County and the annual average water quality data in Shungta Reservoir from 1993 to 2008. Then multiple linear regression analysis was used to obtain four regression equations reflecting the relationship between human activities and water quality, it shows the main impacts on water quality were agricultural activities and land use changes caused by agricultural activities. The major pollution sources of water quality in reservoir was non-point source pollution aroused by agricultural activities, and the impacts of industrial activities on water quality was not reflected in the regression equation. In the course of agricultural activities and other conditions do not change, each increasing of 10 thousand mu of cultivated land will cause the pH index increasing 0.062, dissolved oxygen index dropping 0.046, potassium permanganate index increasing 0.103, chemical oxygen demand index increasing 0.617; and each increasing of 10 thousand tons of nitrogen fertilizer will cause pH index increasing 1.837, and alone with total population increasing by 10 thousand, the chemical oxygen demand index will increase 0.798 as well.