太湖流域宜兴片河流生境质量评价

Assessment of river habitat quality in Yixing district of Taihu Lake basin

建立包含河道生境、河岸生境和滨岸带生境3方面共10项的河流生境质量评价指标体系,对太湖流域宜兴片42个样点进行生境评价及空间差异比较,分析不同土地利用类型下河流生境各参数的差异性,探讨河流生境质量指数与富营养化综合指数的相关关系。结果表明:河流生境质量指数分值介于29～79,31.0%样点生境质量处于较差和很差等级,57.1%样点为一般等级,表明整体上生境退化明显;南部丘陵山区河流的生境质量状况好于广大的平原河网区;不同土地利用类型下河流生境质量差异显著,林地区域的生境质量明显好于耕地和建设用地;河流生境质量指数与富营养化综合指数显著负相关,说明水质状况对河流生境质量具有较大贡献。

In this paper, an assessment system including ten indices of river habitat quality for three different habitats （channel, bank, and riparian habitats） was established to assess the habitat quality and compare its spatial difference at 42 sites of Yixing district in Taihu Lake basin, and analyzed the differences of the river habitat parameters under different land use types as well as the correlation between river habitat quality index and eutrophication. The scores of the river habitat quality index at the study sites ranged from 29 to 79. 31.0% of the sites had a poor or very poor habitat quality, and 57.1% had a fair habitat quality, indicating the obvious habitat degradation in the whole district. The river habitat quality was better in southern hilly area than in vast plain river area. There existed significant differences in the river habitat quality under different land use types, being much better in woodland than in farmland and construction land. The river habitat quality index had significant negative correlation with eutrophication, suggesting the considerable contribution of water quality to river habitat quality.