汉江流域荆门段面源污染负荷时空分布与污染现状评价

目的]对汉江流域荆门段面源污染负荷时空分布与污染现状进行分析和评价,为汉江水污染的治理提供科学依据。方法]利用输出系数模型和等标负荷估算法,对汉江流域荆门段的面源污染负荷进行了空间分析和负荷估算,包括总氮(TN)、总磷(TP)、化学需氧量(COD)和氨氮(NH3-N),得出了汉江流域荆门段面源污染负荷及其空间分布状况。结果]在所有污染源中,农村生活、畜禽养殖、降雨、土地利用和城镇径流是5个主要的面源污染源;该地区各市县总氮和总磷污染负荷与COD和氨氮污染负荷的输出量的排序均表现为:钟祥市沙洋县东宝区掇刀区;各类污染源总氮贡献率排序为:农村生活农业用地畜禽养殖降雨非农业用地;各类污染物总磷贡献率排序为:畜禽养殖农村生活农业用地非农业用地降雨。结论]总体来说,河流富营养化主要是由于农村污染物未经处理排放或处理措施不当引起的。

Spatial Distribution and Evaluation of Non-point Pollution Source in Jingmen Region of Hanjiang Watershed

Objective] To provide scientific basis for the water pollution control of Hanjiang, the estimation based on the temporal and spatial distribution of non-point source pollution in Jinmen region of Hanjiang watershed was conducted.Methods] The export coefficient model and the equivalent standard pollution index method were used to illustrate the temporal and spatial distribution and estimated the loads of the non-point source pollution in Jinmen region of Hanjiang watershed, including TN, TP, COD and NH₃-N.Results] Rural domestic wastes, livestock breeding, rainfall, land use and urban runoff are the major sources of non-point pollution. Based on the pollution stress, spatial distribution of the pollution source load of different cities was found in the following order:Zhongxiang City > Shayang County > Dongbao District > Duodao District. The contribution of different pollutant sources had a rank of urban runoff < rainfall < land use < rural domestic wastes < livestock breeding.Conclusion] The poor management of pollutants, particularly of the sewage (none or inappropriate treatment), might be the prominent reason of river eutrophication.