The Research Of The Adjustment Of The Agricultural Structure In Northern Zhejiang Province Under The Constraint Of Water

Agriculture is our country’s first production, which has an irreplaceable foundation status. China’s agricultural structure is not reasonable. The proportion of farming is too high and the proportion of livestock and poultry breeding is too low. Moreover, the agricultural products’ added value is too low. Meanwhile, pur country’s agricultural nonpoint pollution is serious, which is a major source of pollution to lakes and reservoirs.The study area of this research includes Yuhang, Lin’an, Anji, Changxing, Deqing and Wuxing. This research has two parts, the first part is about the agricultural nonpoint pollution load and the analysis of its characteristics. The second part is about how to optimize the agricultural structure of northern Zhejiang province. The purpose of this research is to reduce the emission of agricultural nonpoint pollutants by optimizing the agricultural structure using a linear programming model.The main conclusions of this research are as follows:(1)The agricultural nonpoint pollution of northern Zhejiang province is serious, the emission of COD is the highest of all, being up to61648.78t, which is followed by TN (14817.52t) and TP (2359.36t).(2)TN has the highest standard discharge rate, reaching49.90%, which is followed by TP, whose ratio is39.72%. And the ratio of COD only reaches10.38%. It means TN impacts the water environment most seriously, followed by TP and COD.(3)The emission of agricultural nonpoint pollutants of northern Zhejiang province in the year of2011is up to2.26×1010m3and it has reduced to1.58×1010m3after the agricultural structure adjustment. The reduction rate reaches29.77%. Meanwhile, the reduction rates of COD, TN and TP reach36.04%,19.87%and40.57%, respectively.