北京密云水库及入库径流水化学特征分析

Water chemical properties of Miyun Reservoir,Beijing and the main rivers flowing into the reservoir

该文对北京密云水库和森林植被影响下不同水源的水化学特征进行了调查与分析.结果表明:密云水库河川径流中的化学元素含量不仅与降水化学组成有关,而且受该地区的土壤、植被及人为因素影响较大.2003—2005年密云水库水质富营养化比1987年加剧,其中白河对密云水库中化学元素入库负荷贡献最大,达到密云水库水体对应数值的46.20%;潮河其次,为30.02%;白马关河仅为4.97%.潮河和白河河水的N、P含量大于白马关河和安达木河,而K含量正好相反,这种含量差异主要是由于各流域土地利用及施肥等情况不同而造成的.密云水库流域的水源涵养林对大气降水、农田径流的水质净化效果显著.

This paper investigated and analyzed the water chemical properties of Miyun Reservoir, Beijing and the varied river runoff affected by forest vegetation in the Miyun Reservoir Watershed. The results showed that the concentrations of some elements in the rivers and creeks flowing into the Miyun Reservoir were not only related to the chemical composition of precipitation in open field, but also affected by the characteristics of local soil, vegetation and human factors. The water eutrophication pollution of Miyun Reservoir during the period of year 2003-2005 was more serious than those of the past 20 years. The pollution contribution from the Bai River Sub-watershed was the largest, which accounted for 46.20% of the Miyun Reservior; while that of the Chao River was the second by accounting for 30.02% of the reservoir; and the third was the Baimaguan River by accounting for 4.97 % of the reservior. The concentrations of N and P in Chao River and Bai River were higher than those of Baimaguan River and Andamu River, but the situation was contrary for the element K. The above concentration differences might be caused by the variances in land use and fertilization. The waterhead-protection forests in the Miyun Reservoir play a key role in improving the water quality of precipitation and farmland surface flow.