长沙市土地利用变化对非点源污染分布的影响研究

以长沙市为研究区域,利用1986和2000年2个时段的土地利用图,分析土地利用方式的变化,结合土壤普查图和降雨数据,利用L-THIA模型,估计2个时段研究区域长期平均非点源污染输出负荷,并分析其空间分布的变化。结果表明,从1986至2000年的15年期间,长沙市的林地和草地有向城镇、农村居民点用地和农业用地转化的趋势,其中农业用地由原来的23.12%增加到了34.81%左右,城镇用地和农村居民用地分别由原来的1.25%,0.10%变成为2.94%,0.27%,这使得1986～2000年间非点源污染敏感区面积不断扩大,污染程度在不断增加。为了控制非点源污染,根据非点源污染分布情况和土地利用方式,将长沙市分为东、中、西部3个防治区,分别采用不同的措施。

Study on the Effects of Land Use Change on Non-point Pollution Distribution in Changsha City

Taking Changsha City as a case study,combined with the land use pattern of 1986 and 2000 as well as soil and precipitation data,the dynamic change of land use pattern was analyzed and the long term average pollution loads were estimated using L-THIA model.Then the dynamic change of the distribution of non-point source pollution was analyzed.The results showed there was a significant trend of transforming from forest and glass land to urban,agricultural and rural residential areas.The agricultural areas increased from 23.12% to about 34.81% of the total watershed,and the urban and urban residential areas changed from 1.25%,0.1% to 2.94%,0.27%,respectively,which made the sensitive areas of non-point source pollution expanding,and the pollution degree was more and more serious from 1986 to 2000.In order to alleviate the impacts of land-use change,Changsha was divided into two prevention zones,based on the distribution of non-point source pollution and pattern of land-use,where different measures should be taken.