基于经典的输出系数法,以上海滴水湖集水区为例,初步探讨了适合于中国东部平原河网地区的半分布式集水区非点源输移通量测算方法及其应用.结果表明:(1)结构方面,滴水湖集水区非点源类型主要包括土地利用、降雨以及分散排放的农村生活污水3类,土地利用是最主要的非点源类型;(2)时间尺度,1965~2008年,滴水湖集水区非点源污染物输移通量呈现增加态势,非点源污染问题基本经历了从不明显到初步显现再到凸显的3个阶段;(3)空间尺度,13个二级集水区和137个三级集水区的输移通量分布与功能定位、城市化程度以及有效绿地面积比例有关.
In this paper,the semi-distributed calculation method for the transport flux of the non-point source(NPS) at the watershed scale in the tidal plain of eastern China was proposed based on the classical export coefficient modeling approach,and the method was applied to the case of Lake Dishui watershed in Shanghai.The results show that:(1) among land use,rainfall and scattered-rural sewage,land use has been the biggest NPS;(2) from 1965 to 2008,NPS pollution has been increasing through three stages of unobvious,preliminary obvious and very obvious;(3) the spatial distribution of the transport flux of NPS in 13 secondary sub-watersheds and 137 tertiary sub-watersheds is in association with the functional orientation of sub-watersheds,the degree of urbanization and the effective green area.