汉江上游金水河流域森林植被对水环境的影响

以汉江上游金水河流域为研究区域,分析了流域森林植被对水环境的影响。利用年降水量、林冠截留率和不同森林类型面积的数据,计算了金水河流域森林生态系统的水源涵养量,分析了流域森林植被对水量的影响;采用监测的方法,分别对金水河流域阔叶林森林生态系统的大气降水、枯落物层、土壤层和出口河水的水质进行了比较分析,探讨流域森林植被对水质的影响。结果表明,(1)金水河流域森林生态系统的水源年涵养总量为466.79×106m3,(2)流域阔叶林森林生态系统能够调节pH值,缓解大气降水的酸性环境;降低了大气降水中TDS、CODMn、HCO3、SO4、Cl、NO3、NH4-N、NO3-N、PO4-P、TDP、As、Ba、Cr、Na、Pb、Fe、K、Mn、V和Zn的含量,净化了水质。(3)根据各贮水层的水质分析,推断了河水中各物质的不同来源。研究为南水北调中线工程水源地的管理和建设提供了参考。

Impacts of forest vegetation on water environment of the Jinshui River Basin in the Upper Han River

As a case study of area in the Jinshui River basin of the upper Han River, the impacts of forest vegetation on water environment were investigated. The water conservation volumes were calculated by using the annual rainfall, crown cover interception rate and areas of different forest types. The effects of the forest ecosystem on water quality were determined by monitoring and comparing the water quality of rainfall, litter layer water, soil layer water and river water in the river outlet for the broad-leaf forest ecosystem of the basin. The results indicated that (1) the annual conserved water volumes through the forest ecosystem of the Jinshui River basin was about 466.79×106 m3. (2) The pH values could be regulated by the broad-leaf forest ecosystem of the basin, which alleviated the rain acidity. Similarly, the physico-chemical concentrations of rainfall, including TDS, CODMn, HCO3, SO4, Cl, NO3, NH4-N, NO3-N, PO4-P, TDP, As, Ba, Cr, Na, Pb, Fe, K, Mn, V and Zn, were reduced, and hence the water quality was purified. (3) The sources of matter in the river water were different based on the assessment for the water quality in different water layers. Thus, the study provided a reference for the management and construction for the water source area of the Middle Route of South-to-North Water Transfer Project, China.