Study On The Environmental Loads And Economic Losses From Agricultural Non-point Source Pollution In Plain River Network Region

Plain river network region is generally characterized by numerous rivulets, flat water flow, and low environmental carrying capacity.. With the rapid development of local economy, water pollution in such regions becomes increasingly serious due to heavy discharge of pollutants. In this study, we chose two typical plain river network regions, Xueyan town in Yangtze river basin and Changdang town in north and coastal area of Jiangsu Province,as the research sites. Xueyan town has developed industry, agriculture and service sector, while Changdang town is located in a crucial production base of grain and cotton in China, with the agriculture as its major economic pillar. Low disposal rate of the wastes discharged from cultivated field, livestock breeding and rural household d has caused serious agricultural non-point source pollution and economic losses in these two sites. We made a preliminary study of the problem of agricultural non-point source pollution in plain river network area, including the load estimation of agricultural non-point source pollution and analysis of the difference in agricultural non-point source pollution between the two representative towns. The environmental economics method was firstly used to estimate the losses of agricultural non-point source pollution in this area. This research will provide foundation to find the key area of pollution and estimate the losses of non-point source pollution.Johnes Export Coefficient Model was chosen to estimate the load of agricultural non-point source pollution in Xueyan town and Changdang town, Shadow engineering method and alternative pricing method were used to make a quantitative analysis for the economic losses caused by agricultural non-point source pollution. The results showed that:Agricultural non-point source pollution load of TN, TP, COD were140265kg,21447kg,607430kg; delivered-to-rivers loads were66970kg,6722kg,275781kg in Xueyan in2008. Agricultural non-point source pollution load of TN, TP, COD were922453kg,325509kg,3892290kg; delivered-to-rivers loads were217600kg,40756kg,806467kg in Changdang in2010.The agricultural non-point source pollution in Changdang was more serious than Xueyan. There was a significant difference of agricultural non-point source pollution between Xueyan and Changdang because of difference of industrial structure, farm methods, living habits, pollutant treatment rate and government management. The agricultural non-point source pollution loads of TN and COD mainly derived from rural living pollution in Xueyan, they were53.2%and54.0%, the loads of TP mainly derived from livestock breeding in Xueyan, It was62.3%. According to the pollution of each index, rural living pollution and livestock breeding were the main sources of agricultural non-point source pollution in Xueyan, The proportion of farm runoff pollution was the lowest. The agricultural non-point source pollution loads of TN, TP and COD mainly derived from livestock breeding in Changdang, they were74.3%,94.9%,78.1%. Rural living pollution and farm runoff pollution were the next. The difference of cultivated field area, livestock breeding number and rural population caused the difference of agricultural non-point source pollution between Changdang and Xueyan. Xiuyi village was the most serious polluted area in Xueyan, the pollution load ratio of TN, TP and COD were11.5%,17.7%,12.8%, Dongyanghu, Wanshou were the next. Shengliqiao village was the most serious polluted area in Changdang, the pollution load ratio of TN, TP and COD were21.8%,28.0%,22.5%, and Jiahou, Dongxia village were the next.The total economic losses of Xueyan in2008and Changdang in2010were2.430million yuan and7.236million yuan. Changdang lost more than Xueyan. Rural living pollution caused economic losses is the major one lose in Xueyan, It was67.3%. Soil erosion and livestock breeding pollution were the next. They were21.7%and11.0%. While livestock breeding pollution was the major one in Changdang, it was50.3%. Rural living and Soil erosion pollution were the next,they were36.0%,13.7%. The regional distribution of economic loss in Changdang and Xueyan is not the same, there was a big difference. Xiuyi village was the largest economic loss area in Xueyan, Gongjian and Dongyanghu were the next, In Changdang, Shengliqiao village was the largest economic loss area, Jiahou and Dongxia were the next.