滇池流域土地利用景观空间格局对水质的影响

摘要

This study deals with a comprehensive water quality assessment for Dianchi Basin. Based on the water quality assessment method, NP, PD, LPI and LSI were selected as the key parameters to describe the landscape patterns, and it is analyzed the impacts on water quality from the dominant landscape patches of the basin. The results indicated that the quantity and irregularity in shapes of urban patches were positively correlated with the delayed deteriorate of water quality; While concentrated large farmland patches contribute to the generation of non-point pollution, but the pollutant concentration in runoff gradually reduced when it flows through large farmland patches due to the absorption by the farmland soil; The higher density of forest patches, the greater effect of adsorption of contamination in run-off, but large patches may result in the limitation in which the pollutants, without flowing through forests, can go into the river directly to contaminate the water quality.%选用综合水质评价方法,对滇池流域进行水质评价.选取斑块数量(NP)、斑块密度(PD)、最大斑块指数( LPI)、最大形状指数( LSI),作为表征景观空间格局的参数,来分析流域优势斑块对水质的影响.对水质评价结果与景观指数进行相关性分析得出:居民点及工矿用地斑块数量越多、形状越不规则,有利于延缓水质状况的恶化；耕地斑块越大,越集中,本身产生的面源污染浓度就越高,而流经耕地的径流中的污染物浓度则会因大斑块的吸附过滤作用而降低；林地斑块密度越大,对污染物的截留纳污作用就越大,而斑块越大,可能产生局限性,导致未流经林地的污染物直接进入河流而影响水质.