京杭大运河无锡段水质和土地利用的响应关系

Response Relationship between Canal Water Quality and Land-use Using Space Statistical Modeling

以京杭大运河无锡段2003年7月和12月两景SPOT-5正射影像为数据源,结合断面水质数据,利用基于最小二乘法的多元回归方法,建立了枯水期和丰水期水质参数与土地利用的响应模型。结果表明:以监测断面为中心的缓冲区距离的空间变化与水质监测指标之间有很明显的响应关系,建立的模型显示,丰水期DO、CODMn、BOD5、TN和TP的最大响应宽度分别为100、100、300、200和100 m,枯水期的最大响应宽度则为5002、003、004、00和200 m。运河的水质污染主要受离河岸较近的土地利用结构的影响,耕地上产生的农业污水、商业和工业中的废水以及大面积裸地上居民生活垃圾和建筑垃圾产生的污水是导致京杭大运河无锡段水质恶化的重要原因。

Taking two SPOT-5 orthophoto images of Beijing-Hangzhou Grand Canal in 2003 as the data source,this paper uses the least square multiple regression to build the model between water quality data and land-use proportion in high flow period and low water period.The result shows that the spatial change of the buffer distance which is the center of the monitoring sections presents obvious responsive relationship with water quality monitoring indexes.In high flow period,the maximum response ranges of DO,CODMn,BOD5,TN and TP are 100 m,100 m,300 m,200 m and 100 m,respectively.But in low water period,the maximum response ranges are 500 m,200 m,300 m,400 m and 200 m.The canal water pollution is influenced by neritic land-use structure.Agricultural effluent,commercial and industrial wastewater,bare land effluent,which are composed by living rubbish and construction refuse,are the important reasons to cause the Beijing-Hangzhou Grand Canal water quality deterioration.