基于污染足迹的太湖流域稻作农业污染评估--以常州市和宜兴市为例

稻作农业在保障粮食安全方面贡献巨大,但因经济利益驱动,化肥农药被过量施用,造成了氮、磷等营养物质流失,对水环境产生严重影响。本文基于全国第一次污染普查数据,结合各类污染物的产排污系数计算了稻作农业COD、TN和TP入河量,通过污染足迹模型计算了稻作农业COD、TN和TP的污染足迹,通过污染压力模型计算了稻作农业COD、TN和TP的污染压力指数,并对其进行评估。结果表明:(1)常州市、宜兴市稻作农业生产过程中向水环境排放的污染物中以COD和TN为主,其入河量分别为792.96 t·a^-1和605.28 t·a^-1,TP入河量为27.16 t·a^-1;(2)常州市、宜兴市稻作农业TN污染足迹最大(3 944.50 hm²),其次为TP污染足迹(2 578.95 hm²),最小的是COD污染足迹(523.52 hm²);(3)常州市、宜兴市稻作农业对水环境的污染压力指数为2.10,处于中度污染压力状况,表明常州市、宜兴市稻作农业生产活动超出了当地水域的承载能力,对当地水环境产生了压力。

Pollution Assessment of Rice Agriculture in the Taihu Lake Watershed Based on the Pollution Footprint: A Case Study of Changzhou City and Yixing City, China

Rice agriculture has been proved to make a great contribution to the food quantity security, but farmers are driven by economic in-terests to overuse the pesticides and chemical fertilizers. The water environment is getting worse and worse. Based on the first national census of pollution data and the production and drainage coefficient of the pollutants, this paper calculated pollutant (COD, TN and TP)quantity in-lets into river from rice agriculture. The pollution footprint based on the pollution footprint model and the pressure index of pollution based on the pollution pressure model were also calculated. The results showed that the river discharge of COD and TN took the most part in that of COD, TN and TP. The river discharge of COD, TN and TP was 792.96 t·a^-1, 605.28 t·a^-1 and 27.16 t·a^-1 respectively. The pollution footprint of TN was the largest, which was 3 944.50 hm², the second was the pollution footprint of TP, which was 2 578.95 hm², the smallest was the pollution footprint of COD, which was 523.52 hm². The pollution pressure index of rice agriculture was 2.10, indicating that the river is in a moderate pollution stress condition. So the pollutant river discharge of the rice agriculture is beyond the carrying capacity of the local waters.