青藏高原地区典型公路路域水环境特征

目的]阐明青藏高原地区公路路域水环境特征及影响因素,为青藏高速公路建设及水环境保护措施提供理论基础及科学依据。方法]基于2015年6—7月对共玉公路(青海省共和县至玉树县)和青藏公路(格尔木市至拉萨市)路域水环境测试结果,对青藏高原地区公路路域水环境特征及影响因素进行分析。结果]经T检验,青藏高原地区公路路域径流污染具有显著性差异,各水质指标存在不同程度的变异性,变异系数(Cv)变化范围为11%~396%,表明不同径流水体污染物因所处位置不同而有所差异;对比了典型路域水环境特征,新建公路(共玉公路)的水环境质量好于运营期公路(青藏公路),高速公路运营后对路域水环境影响明显;对不同径流水体进行了Person检验。结果显示,悬浮物(SS)与其他水质参数之间均表现出不同程度的相关性,说明SS不仅是青藏高原地区路域径流污染的主要污染物,且是其他污染物(重金属和化学需氧量COD)的载体。结论]路面径流是路域水环境污染的重灾区,对降雨径流进行收集处理及采用新型的路面,布置径流处理措施,将有效地降低路域水环境的影响。

Characteristics of Water Environment at Road Area of Typical Highway in Qinghai Tibet Plateau

Objective] The objective of the study is to investigate the characteristics of water environment and influencing factors at road area of highway in the Qinghai Tibet Plateau, and to provide theoretical basis and scientific support for the construction of the Qinghai Tibet highway and water environmental protection measures. Methods] Based on the test results of water environment along Gongyu highway(from Gonghe to Yushu County in Qinghai Province) and Qinghai Tibet highway(from Geermu to Lhasa City) in June to July of 2015, we analyzed water environment characteristics and influencing factors in highway road area in Qinghai Tibet Plateau. Results] Statistic test showed that the significant differences existed in runoff water pollution in highway road area of the Qinghai Tibet Plateau, and high variability was found in the water quality indexes, with coefficient of variation(C_v) ranging from 11% to 396%, indicating that pollutant in runoff varies by location. We also compared water environment characteristics in typical highway areas, and found that water environment quality was better in new highway area than old highway area. The highway operation had a significant impact on water environment. Person test showed that runoff water, suspended solids(SS) and other water quality parameters was correlated with each other to a certain degree, indicating that SS was not only the main pollutants of runoff in the Qinghai Tibet Plateau region, but also is the carrier of other pollutants, including the heavy metals and chemical oxygen demand(COD). Conclusion] Road runoff is the main source of the water pollution in road area, collection and treatment of road runoff and the use of new pavement will effectively reduce the impact of highway on water environment in the highway area.