关键词: 太湖流域跨界区, 农业面源, 污染负荷, 入水强度

Abstract:

To illustrate the transboundary non-point source agricultural pollution in the Taihu valley, first of all, COD, TN and TP loads in the pollution were figured out with an export coefficient model by calculating the loads separately in the three major contributors of the pollution, i.e. domestic sewage and household refuse from rural population, agricultural runoff and waste from livestock keeping, and temporal and spatial variations of the loads were characterized; Then, discharge intensities of the loads in various regions of the transboundary area were evaluated with the extremum method and the mean variance weighting method. Results show that during the years from 2010 to 2013, the COD, TN and TP loads on the whole were on a declining trend; during the four years, high COD load appeared in Huzhou and Jiaxing and high TN and TP loads in Suzhou, Huzhou and Jiaxing; livestock keeping was the main contributor of the three loads, explaining 80% of the total load. Evaluation of discharge intensity of the loads indicates that the comprehensive index of the non-point source agricultural pollution per unit GDP was 0.217 6, 0.240 2, 0.236 4 and 0.222 2, respectively, for the four years, which did not show any rule of variation, while the comprehensive index of the non-point source agricultural pollution per unit area was 0.407 8, 0.289 9, 0.289 2 and 0.281 6, which obviously followed a declined trend.

Key words: transboundary area in the Taihu valley, non-point source agricultural pollution, pollution load, discharge intensity