Abstract: Based on former research and field survey data, the discharge, loss, composition and regional features of non-point source (NPS) pollution in Shiyan City were studied with the method of pollution discharge coefficient. The results show that pollutants of total nitrogen (TN) , total phosphorus (TP) flowing into water respectively were 17900 tons and 3800 tons for various NPS in 2004. Chemical fertilizer and animal waste were the primary source of TN, respectively, accounting for 39% and 25%. The main sources of TP came from soil erosion, fertilizer pollution and aquaculture, which made up more than 60% of TP. Among the districts (counties) of Shiyan City, Danjiangkou and Yunxi had the most serious NPS pollution, while the municipal district had the smallest. Different pollution types dominated in different districts or counties. Danjiangkou was featured by aquaculture pollution type; Yunxi, the type of fertilizer pollution; Zhushan and Yunxian, the type of fertilizer-soil pollution; and municipal district, Zhuxi and Fangxian were featured by comprehensive pollution type. Those results can be referenced by local government for making scientific NPS control strategies in Danj iangkou reservoir.

Key words: non-point source ( NPS) pollution, pollution discharge coefficient, comprehensive assessment, regional features

摘要： 基于已有研究进展和实地调查资料, 研究了十堰市所辖县市区非点源污染物的产生量和流失量、污染源构成及区域分布特征。研究表明: 2004 年因各种非点源污染流入水体的污染物总氮(TN) 、总磷( TP) 分别为 1. 79 万t和 0. 38 万 t。TN 主要污染源是化肥施用和畜禽粪尿, 分别占39% 和 25% ; TP 主要污染源是水土流失、化肥污染 和水产养殖, 三者之和占到 TP 流失量的 60% 以上。十堰市所辖县市区中, 郧西县和丹江 口市非点源污染最为严重, 市辖区污染最小; 丹江口市为水产养殖污染型, 郧西县为化肥污染型, 郧县和竹山县为化肥-水土流失污染型,市辖区、竹溪县和房县为综合污染型。该研究结果可为丹江口库区非点源污染控制策略的制定提供参考。

关键词: 非点源污染, 排污系数法, 综合评价, 区域特征