太湖河网地区农村非点源氮负荷--以宜兴市大浦镇为例

Nitrogen load from rural non-point source in river network region, Taihu Lake:A case study from Dapu Town in Yixing City

采用野外试验与实地调查相结合,利用泥沙流失方程和GIS平台,定量估算了江苏宜兴市大浦镇农村非点源氮排放负荷。结果表明:大浦镇农村非点源氮排放负荷为207.0t.a-1,其中农田、生活污水、养殖、垃圾和非农田泥沙流失的排放负荷分别为80.6、61.1、49.3、10.5和5.4t.a-1,分别占39.0%、29.5%、23.8%、5.1%和2.6%;5种排放源中,农田、生活污水和养殖为优先控制因子;方钱、大浦、浦北和浦南4村平均氮排放负荷为80.4、73.0、60.4和52.3kg.hm-2.a-1,远高于其他区域,为优先控制区。

With soil loss equation and GIS platform, the nitrogen load from rural non-point sources was estimated by a combination of field experiments and survey in Dapu Town, Yixin City, Jiangsu Province. Results showed that the non-point discharge of nitrogen from Dapu Town were about 207.0 t · a^-1, which was composed of 80.6 tons of farmland, 61. 1 tons of living sewage, 49.3 tons of fishery, 10.5 tons of garbage and 5.4 tons of sediment production per year, which occupied 39.0% , 29.5% , 23.8% , 5.1% and 2.6% , respectively. The critical control factors of the five nitrogen sources were farmland, living sewage and fishery. The average nitrogen discharge from four villages, Fangqiang, Dapu, Pubei and Punan, were 80.4, 73.0, 60. 4 and 52.3 kg · hm^-2 · a^-1, which were much higher than that from other villages. Therefore the four villages were critical control areas.