Preliminary Exploration on Water Pollution from Non-Point Source in XiangXi River

Eutrophication is a worldwide pollution problem, when the point source pollution is efficiently controlled, pollution load from non-point source has the increasing proportion in the total load. Xiangxi River is selected as the research demonstration area to conduct preliminary study on non-point source pollution for frequent water bloom. Non-point source pollution factors are analyzed in Xiangxi River such as precipitation, land use, terrain, topography and soil P speciation, it is Al-P> Ca-P > Fe-P > D-P > Od-P > Org-P > Oc-P in farmland soil samples , Od-P > Ca-P > D-P > Org-P > Fe-P > Oc-P > Al-P in woodland soil samples,and Ca-P > Fe-P > Od-P >D-P > Al-P > Oc-P > Org-P in orchardland soil samples. Listing TN, TP and D-Si monitoring results in Xiangxi River backwater reservoir since 2004, and monitoring runoff water quality and quantity in Gaolan River and upstream Xiangxi River. According to runoff partition principle, nonpoint source TN and TP pollution load account for 42.6% and 46.3% of total amount upstream Xiangxi River.