喀喇昆仑公路沿线地表水理化特征分析

Analyses on the Physical and Chemical Properties of Surface Water along the Karakoram Highway

研究喀喇昆仑公路沿线地表水环境基本特征,为公路改扩建施工中开展水环境保护提供支持.2008年9月-2009年10月在喀喇昆仑公路沿线的印度河、洪扎河和红其拉甫河采集地表径流样,分析了样品中pH值和悬移质浓度,现场监测了水体透明度.结果表明：所有样品的pH值介于6.7-7.5之间,悬移质浓度分布在0-1 841 mg.L-1之间,水体透明度在2-107 cm.公路沿线地表径流的pH值基本呈中性,pH值的变化受补给的冰川融水pH值的时空变化规律影响;地表径流中悬移质是影响水体透明度的主要因素.监测数据还显示,气温影响下的冰川融水径流形成的水文过程是悬移质时间变化的主要控制因素,3条河流中悬移质浓度存在明显的空间分布规律,其中红其拉甫河中上游河段水中悬移质浓度含量较低,是喀喇昆仑公路改扩建工程施工中水环境保护的重点河段.

In order to study the environmental properties of surface water along the Karakoram Highway,and to provide good protection of water resources in the process of improvement of Karakoram Highway,samples were collected from the Indus,Hunza River and Kunjirap River along the Karakoram Highway from September 2008 to October 2009.pH values and concentrations of suspended sediment were analyzed.Transparency was monitored in the sampling sites.The results indicate that pH value varied from 6.7 to 7.5,and the concentration of suspended sediment was 0～1 841 mg·L-1.The transparency varied from 2 to 107 cm.The study indicates that the surface runoff was almost neutral pH,the dependence of water transparency on concentration of suspended sediment was searched.The changes in surface stream water quality,including pH,water transparency and suspended sediment are controlled by the quality of meltwater,and the temporal change of suspended sediment is depended on hydrological factors.The concentrations of suspended sediment in the three rivers are spatially different.The concentration of suspended sediment in the upper reaches of Kunjirap River is lower,so it is the key section for protecting water environment in the process of reconstruction and extension of the Karakoram Highway.