黄河河川基流量演化规律及其驱动因子探讨

河川基流量是指地下水补给河川径流的水量。论文首次对黄河河川基流量50年来的时空演化规律和驱动因子做了较为全面的分析。研究表明:黄河河川基流量约占黄河河川径流量的44%,黄河河川基流量对维持健康黄河具有重要意义。受自然变化和人类活动影响,黄河干支流河川基流量50年来总体呈下降趋势;支流基流量变化可划分为双峰型、单峰型、直线下降型3种类型,干流区间基流量主要减少在黄河中游地区。黄河河川基流量具有维持河川径流、维护河流生态、湖泊以及表生生态植被良性发展等多种功能,河川基流量衰减导致湖泊萎缩、表生植被退化、加剧黄河断流等一系列生态环境负效应。通过对驱动因子进一步分析表明,降水量是维持河川基流量的主要来源,其变化影响黄河河川基流量变化趋势。人类活动是黄河河川基流量驱动因子中最活跃的因子,基流量衰减最明显的地区也是人类活动频繁的地区。因此维持健康的黄河必须要对黄河基流量进行科学保护和合理开发利用。

Change Characteristics and Driving Forces of Base Flow of Yellow River Basin

Base flow is one of the primary parts of the river runoff.In this paper,through the analysis of base flow of 10 control stations on the mainstream and 15 tributaries from the 1950's to 2000,the authors firstly analyzed the characteristics and driving forces of base flow of the mainstream and tributaries of the Yellow River basin.The result showed that first,the base flow of the Yellow River is 44% of runoff of the Yellow River,and so it is important to maintain sustainable development of the river.Second,influenced by the natural change and human activity,base flow of the mainstream and tributaries of the Yellow River basin is down generally in the past 50 years,base flow of tributaries of the Yellow River basin is divided into three types as double-humped curve,single-humped curve and linear decrease curve,base flow between two stations of the mainstream of the Yellow River is mainly reduced in the middle reaches of the Yellow River.Third,base flow of the Yellow River has such eco-environmental functions as maintaining runoff,keeping river eco-environment and improving surface vegetation.Reduction of base flow of the Yellow River leads to negative eco-environmental effect such as lake shrinkage,vegetation degeneration,aggravating Yellow River cut-off.Forth,formation,development and evaluation of base flow of the Yellow River are the integrative effect of natural factor and human factor.The result showed natural factor,mainly including precipitation,decides the structure in time and space of base flow of the Yellow River basin.Human factor,including riverside pumping,metal mining,building reservoir,soil and water conversation,exerts influence on increasing or decreasing base flow of the Yellow River.Exploitation and utilization of groundwater is the most important factor in all kinds of human factors.The human activity is intense and frequent in the middle reaches and Datonghe river,Huangshui river basin of the upper reaches of the Yellow River,where the base flow of the Yellow River is reduced significantly.So,maintaining normal Yellow River condition needs scientifically protecting and rationally exploiting and utilizing base flow of the Yellow River.