南淝河水-沉积物中重金属的分布规律、环境评价与溯源研究

系统分析了南淝河丰水期和枯水期表层水及沉积物中As、Cd、Cr、Cu和Pb的含量,结果表明:Cd污染最为严重,表层水中Cd含量属于劣Ⅴ类地表水标准,沉积物中Cd含量超过合肥市土壤背景值,最高值达到背景值的7.5倍;单因子水质指数法评价结果显示Cd未达到水体功能区目标,其余元素基本达到了水体功能区目标,地累积指数评价结果表明各采样点污染程度在无污染到轻度污染之间,潜在生态风险指数评价结果显示各采样点均属于中度生态危害水平,3种评价结果均显示Cd是主要污染因子。主成分分析结果表明南淝河沉积物中不同时期重金属污染来源存在一定差异性和多样性。

STUDY ON THE ECOLOGICAL SYSTEM OF KEY ECOLOGICAL FUNCTION ZONES SENSITIVITY BASED ON GRID GIS: A CASE IN LEISHAN COUNTY OF GUIZHOU PROVINCE

In order to diagnose the environmental problems,and realize the importance of protection ecological condition,taking the key ecological function area-Leishan County as example,the paper constructed index system of ecosystem sensitivity evaluation in support of the gridding GIS technology and combined with the terrain,landforms and climate data.Using the analytic hierarchy process,the regional comprehensive method and the gridding GIS technology,this paper gave each index in the evaluation system by the spatial expression of 10 m × 10 m grid scale.The spatial pattern of ecological sensitive for study area was got by applying the spatial overlaying technology based on grid data and ecosystem sensitivity evaluation model.The results showed:Non-sensitive area and slight-sensitive area were smaller,accounted for only 5％ and 13.4％;middle sensitive area and extremely sensitive accounted for 26.3％ and 17％;the area of highly sensitive area was the largest,accounted for 38.3％.