无锡各地农业活动对太湖总磷、总氮的影响识别

选择化肥剩余、有效灌溉面积为影响因子，前者为“物源”，后者为“动力”；采用结合TOPSIS法及多元相关分析和排除法，探讨太湖水体总磷、总氮的浓度（C_TP、C_TN）与无锡各地农业生产投入的关联性，判别太湖C_TP、C_TN的主要农业来源区域。结果表明，由于化肥施用量多或/和化肥利用效率相对较低，宜兴、市辖区农业活动中产生的化肥剩余量较大；在“物源”与“动力”的共同作用下，市辖区、宜兴的农业活动对太湖水质有较大影响；而因“动力”不足，虽然化肥剩余量较大，但宜兴农业活动对五里湖、市辖区农业活动对西部沿岸水体的影响却不大；因“物源”不足，江阴的氮肥剩余对五里湖与梅梁湖C_TN的影响可以排除。

Distinguishing Influence of Agriculture Activities in Each District of Wuxi on Phosphorus and Nitrogen in Taihu Lake

In order to discuss the association between the concentrations of total phosphorus (C_TP) and of total nitrogen (C_TN) in Taihu Lake and the resources input in the agriculture of each district of Wuxi and to distinguish the main districts agriculture sources of phosphorus and nitrogen, two factors, the surplus fertilizer and the effective irrigation area are selected. In order to calculate the surplus fertilizer a new method combined with Technique for Order Preference by Similarity to Ideal Solution method is designed. Furthermore, the multi-analysis method and the elimination method were used. The results indicate that owing to the excessive chemical fertilizer application and/or the inefficient fertilizer utilization, the quantities of surplus fertilizer in Yixing and Districts of Wuxi are larger. Under acting together by the material resources and the transmissive motivity, the agriculture activities in Districts of Wuxi and Yixing have the great influence on the water quality of Taihu Lake. However, owing to lack of enough transmissive motivity although a large surplus fertilizers in the agriculture activities of Yixing and Districts of Wuxi are produced, the surplus fertilizer of Yixing has less influence on Wuli Lake and that of Districts of Wuxi has less influence on Western bank of Taihu Lake. And owing to no material source the influence of the surplus nitrogen fertilizer in Jiangyin on C_TN of Wuli Lake and of Meiliang Lake is excluded.