入太湖河流武进港的区域景观格局与河流水质相关性分析

以武进港区域为例,通过遥感解译得到土地利用分类数据,以区域7个水质监测断面为中心生成缓冲区,并借助FRAGSTATS软件计算各用地类型面积比例以及斑块数量(NP)、面积加权斑块分型指数(FRAC_AM)、香农多样性指数(SHDI)、香农均匀度指数(SHEI)、蔓延度指数(CONTAG)等5个景观格局指数,从组成属性和空间属性两方面表征景观格局,进而分析景观格局与河流水质的相关关系.结果表明,区域景观格局与河流水质有显著相关关系:建设用地的面积比例与污染指标呈显著正相关,表明建设用地为区域污染物产生和输出的主要用地类型,也是影响河流水质的关键因素;而耕地的面积比例与污染指标呈显著负相关;各景观指数与水质均存在关联,特别是SHDI和SHEI与污染指标体现了明显的负相关,CONTAG与污染指标体现出明显的正相关.

Relationship Between Landscape Pattern and River Water Quality in Wujingang Region, Taihu Lake Watershed

Wujingang region was taken as the study area to explore the relationship between landscape pattern and river water quality. Remote sensing image was interpreted and buffer zones were constructed, and then landscape patterns characterized by land-use patterns and five selected landscape metrics including Number of patches (NP), Area-weighted mean patch fractal dimension (FRAC _AM), Shannon's diversity index (SHDI), Shannon' s evenness index (SHEI), Contagion index (CONTAG) in each buffer zone were obtained. By employing the correlation analysis between the landscape pattern and river water quality, the results indicated that the river water quality was influenced by landscape pattern. The percentage of built-up area was positively related with water quality indicators, demonstrating that the percentage of built-up area was one of the key factors affecting the river water quality, while the percentage of cultivated land showed a negative relationship. Furthermore, the relationships between the selected five landscape metrics and water quality were also revealed. SHDI and SHEI were significantly positively related with water quality indicators, while CONTAG showed the opposite relationship.