拉萨河流域高寒湿地水质影响因子分析

Analysis of Water Quality Pollution of Alpine Wetlands in the Lhasa River Basin, China

西藏高寒湿地在生态平衡、生态建设和经济社会发展中发挥着重要作用。本文以西藏拉萨河流域内各个典型高寒湿地为研究对象,通过系统聚类法和综合污染指数法,对流域内各项水质指标进行综合分析和评价。结果表明:各个湿地的总N、Cu元素含量都超出了Ⅰ类水质标准;总P、Zn没有超标;Mn元素含量除了塘嘎郭湿地超标3倍外,其他均小于国家标准;Fe元素含量除了塘嘎郭湿地超标7倍外,其他均小于标准。总N、总P、pH值、Cu、Fe等因子对拉萨河流域内各个高寒湿地水质污染贡献最大。拉萨河水体有机污染较重,其余各个湿地有水体富营养化的趋势,同时流域内湿地独特的自然因素造成该流域内重金属污染偏高。对策建议包括应加大对城市污水的治理,加强流域内及周边矿藏资源的开发管理等。

Tibet alpine wetlands play an important role in ecological balance, ecological construction and social development. In this study,combining methods of system analysis and comprehensive pollution index were used to analyze and evaluate the water quality of alpine wetlands in Lhasa River basin. The results indicated that, the content of total nitrogen and Cu of every wetland exceeded the water quality standard levelⅠ, and the content of total phosphorus and Zn did not exceed. The content of Mn did not exceed the standard levelⅠ except Tang Ga-guo wetland, and the content of Fe did not exceed the standard levelⅠ except Tang Ga-guo wetland. Total nitrogen, total phosphorus, pH,Cu and Fe were major factors affecting the water quality. Organic pollution was serious in Lhasa River, the tendency of eutrophication occured on the other alpine wetlands. At the same time, as for the unique natural factors of the basin, the heavy metal pollution was serious in the alpine wetlands. Some measures for example to increase the intensity of governance of city sewage, and the governance of mineral resources in and near Lhasa River basin were put forward.