摘要
南水北调西线一期工程规划从长江上游雅砻江、大渡河的5条支流调水入黄河,总调水量40×108m3。如此大规模的引水是否会对原来河流的功能特别是引水坝址附近生态环境功能造成不利影响?针对该问题,本文在分析调水地区径流特征的基础上,分别采用7Q10法,Tennant法以及湿周法计算了不同引水坝址下游河道的生态环境低限用水需求,推荐西线一期工程各引水坝址下游河道生态环境低限用水量,除克柯坝址为2m3/s,其余坝址均为5m3/s。并据此分析了南水北调西线一期工程实施后对引水河道生态环境的影响。结果表明调水后各引水河流基本上依旧能够满足其河道内生态环境用水需求,不会损害河流基本的生态环境功能。
According to the plan, the first stage project of water diversion from the south to the north via the western course will divert 40×10~8 m^3 water into the Yellow River from Yalong River and five branches of Dadu river of the up stream Yangtse. The question rises as: will the water diversion affect the river environmental function, especially in the areas nearby the dams? It is therefore essential to analyze and calculate ecological and environmental water requirement. Usually, ecological and environmental water requirement is divided into two types namely ecological and environmental water requirement outsides the rivers channels, and ecological and environmental water demand inside the rivers channels. This research focuses on the latter. The definition of ecological and environmental water requirement inside the rivers channels is described and its four quantification methods namely 7Q10, Tennant, wetted perimeter, and R-2 CROSS are introduced in the paper. To estimate ecological and environmental water requirement inside the river channels, the paper applied 7Q10, Tennant, and Wetted perimeter methods to estimate ecological and environmental water requirement inside the river channels of five different dams based on analysis of hydrologic characters of the water diversion region. The minimum ecological and environmental water requirement required by 7Q10 and Wetted perimeter method is about 5m^3/s and 3.5m^3/s respectively, and 8 m^3/s by Tennant method as it needs more water flow during flooding season. Considering the sandiness of the rivers in the water diversion areas is very low in water abundant year and runoff is steady in a year or between years, the results acquired from 7Q10 and Wetted perimeter methods are more rational than those from Tennant method. So we recommend ecological and environmental water flow in river channels of the Keke dams is 2m^3/s, and 5m^3/s in other dams. The fluxes of dams recommended are close to the average runoff of low water month in a long period of 42 years. Based on it, the influence of water diversion on the river environmental function of the first stage project of western course is analyzed. The results show, the rivers can satisfy ecological and environmental water requirements in river channels after water diversion if the minimum flow under the water diversion dams are not less than the ecological and environmental flow recommended for the river channels. The project will not damage environmental functions of the rivers.
出处
《资源科学》
CSSCI
CSCD
北大核心
2005年第4期180-184,共5页
Resources Science
基金
水利部HSY-SL-107项目资助。
