东江上游龙川站水文情势变化分析

针对河道受气候变化和人类活动影响致使水文情势变异的问题,基于东江上游龙川水文站1952~2010年的实测径流数据,利用Mann-Kendall检验方法分析了径流量的变化趋势和变异区间,并引入IHA指标、生态过剩和生态赤字指数来量化东江流域的水文变异程度。结果表明,在过去近60年期间,龙川水文站年径流量呈增长趋势,由于上游水库的调节作用,径流量大小、频率、延时及逆转次数都有显著改变;生态统计分析表明,生态过剩现象较生态赤字现象更为频繁,夏季洪水期高度运用水库调度的情况则除外。可见龙川站水文情势的变化对生态系统具有潜在影响,需加强东江流域的水资源管理来满足供水和生态系统的需求。

Analysis of Flow Regime Changes at Longchuan Station of Upper Dongjiang River

Aiming at the climate changes and human activities lead to flow regime alteration, based on the daily runoff data during 1952-2010 at the Longchuan station of the upper Dongjiang River basin, the Mann-Kendall test method was used to identify the runoff change trends and variation range of Longchuan station. Flow regime changes were quantified with both the IHA parameters and eco-surplus and eco-deficit concepts. We found that the annual runoff had an increasing trend during the past 60 years, and the magnitudes, frequency, duration, and the numbers of reversal of flow at the Longchuan station were greatly modified due to the upper reservoir regulation. The eco-statistical analyses showed that the phenomenon of eco-surplus is more frequent than eco-deficit, except in the summer flood period due to heavy reservoir operation. The results from this study suggest there are potential influences of hydrologic alteration on the ecosystem. Therefore, water resources management needs to be improved to meet the requirements for both the water supply and ecosystem of the Dongjiang River.