基于GIS的农业非点源污染负荷时空分异研究——以宁波市章溪河流域为例

应用基于CIS AreView的AnnAGNPS模型，进行了宁波市章溪河流域的非点源污染负荷的时空分异研究。结合航片解译，利用ArcGIS9．0、TOPAZ模块等建立了研究区非点源污染空间数据库；结合现场资料、相关文献收集，并利用模型参数的CIS提取技术，建立了研究区非点源污染属性数据库。结果表明：在空间分布上，各子流域吸附态氮空间分异较大，溶解态磷的空间分异最小，不同土地利用类型中林地和果园相比农田非点源污染负荷小，不同土壤类型中，水稻土比黄壤和红壤的污染负荷大；在时间分布上，非点源污染负荷主要集中在汛期，超过全年的55％，枯水期低于全年的4％。

Study on Spatio-temporal Distribution of Agricultural Non-point Source Pollutant Loading Based on GIS, in Zhangxi Watershed of Ningbo

The Annualized Non-Point Source Pollution （AnnACNPS） Model based on CIS AreView was applied to study the Spatio-temporal distribution of agricultural non-point source pollutant loading in Zhangxi Watershed of Ningbo. A spatial database of non-point source pollution was established by using modules of ArcGIS9. 0 and TOPAZ based on aerial-photograph interpretation. Furthermore, based on in-situ data and literatures concerned, an attribute database of non-polnt source pollution was established by application of tile GIS extraction technology of model parameters. The results showed that （ 1 ） spatially, distribution of the sub-watershed, adsorbed nitrogen had a big spatial differentiation, while dissolved phosphorus had the smallest one. In terms of land utilization way, the pollutant loading was lower in orchards or woodlands than that in farmlands; in terms of agrotype, pollutant loading in paddy soil was higher than that in yellow soil and red soil. （2） In terms of temporal distribution, the non-point source pollutants focused in flood season, with a proportion of over 55% , while only 4% in dry season.