太湖源林区水系源头水质时空变异与原因探析

位于浙江省临安市太湖源镇的太湖源水系属太湖流域苕溪水的主要水源地,其水质变化关系到下游杭嘉湖平原和江苏省太湖周边地区众多人口的饮用水质安全和生活用水质量。雷竹Phyllostachys praecox林地雷竹笋生产和森林旅游是太湖源镇的两大支柱产业。为监测当地水源水质和探明水质变化原因,对太湖源水系水质时空变化、成因及水质变化状况进行了研究,对水体中氮、磷及有机物质量浓度逐月进行测定分析。结果表明,源头水与其下游水之间水质随空间分布差异巨大;水中氮为严重污染物,其次为有机物。水中的铵态氮、高锰酸盐指数、可溶性有机碳和总磷等也因季节变化有较大波动。水质变化与当地雷竹笋生产和森林旅游及城镇居民生活废弃物排放等密切相关。

Spatio-temporal variations and cause analysis of headwater quality in forest area of Taihuyuan

The headwaters of Tiaoxi River,located in Taihu Headwaters （THH） Township of Lin an City,Zhejiang Province,serve as a source of drinking water for people living in the Tiaoxi River watershed area comprised of Hang-Jia-Hu Plain in northern Zhejiang Province and a region along Taihu Lake in Jiangsu Province. Maintenance with high water quality to the headstreams therefore is of great importance. In recent years,however,with the fast development of heavily fertilized bamboo plantations for edible bamboo shoots and flourishing forest tourism, soil runoff and waste output due to improper deposition and discharge have imposed remarkable risk of water pollution. Protection of the headwater quality in the catchment of THH Township has become more serious than ever. This research project is therefore carried out to monitor water quality of the headwaters down to the lower part of the Tiaoxi River in metropolitan area of Lin＇an City; sources of pollutants are also under investigation. The present paper summarizes our primary results based on monthly water monitoring from May 2006 until March 2007. The results show that water quality varies greatly over the distance from the headwaters to the lower part. Nitrogen （N） is the most serious pollutant. Concentrations of ammonium, organic matter （OM） and phosphorus （P） in the water also change remarkably over time. The results imply that water pollution is closely related to output of organic wastes including household refuse and human waste where tourism is heavily increasing in the headwaters areas. Additionally, the pollution is heavy in the metropolitan area of Lin＇an City and the area of bamboo plantations.