丹江口水库运用对下游水文情势影响研究

为了分析丹江口水库建成投入运行以后对下游河道水文情势的影响,利用黄家港站、襄阳站和皇庄站1961~2000年日平均流量资料,采用水文变化指标法(IHA)和变化范围法(RVA),定量分析了丹江口水库运用前后汉江中下游河道水文情势变化及改变程度。结果表明,在5组IHA水文指标中,除年极端流量发生时间变化不大以外,其他各组水文指标值均发生了较显著变化;黄家港站、襄阳站和皇庄站的整体水文改变度分别为中度、低度和中度改变,这对汉江中下游河道生态系统稳定性和生物多样性带来不利影响。研究成果为丹江口水库生态调度和汉江中下游河道生态修复提供了科学依据。

Impact of Danjiangkou Reservoir operation on downstream hydrological regime

In order to analyze the impact of Danjiangkou Reservoir operation on downstream hydrological regime, based on the mean daily flow data from 1961 to 2010 at Huangjiagang, Xiangyang and Huangzhuang stations, the indictors of hydrological al-teration ( IHA) and range of hydrological variation method ( RVA) were used to analyze quantitatively the hydrological regimes and the hydrological alteration degrees in middle and lower reaches of Hanjiang River before and after the operation of Danjiangk-ou Reservoir. The results show that four of the five IHA indexes have changed significantly except for the timing of annual extreme flow that remained invariable. The overall degree of hydrological alteration of Huangjiagang, Xiangyang and Huangzhuang stations were at medium, low and medium level respectively. The alternation has an adverse impact on ecosystem stability and biodiversity in the middle and lower reaches of Hanjiang River. The analysis result will provide a scientific basis for ecological operation of Danjiangkou Reservoir and ecological restoration in the middle and lower reaches of Hanjiang River.