基于IHA/RVA法的黄河中游环境流量组分与水文情势变化研究

Study on Variation of Environmental Flow Components and Hydrological Regimes in Middle Yellow River Based on IHA/RVA Method

为探究变化环境下黄河中游环境流量组分与水文情势变化情况,采用Kendall秩次相关检验法、Mann-Kendall突变检验法及累计距平法分析了花园口站1960~2016年径流变化特征,在此基础上,运用IHA/RVA法定量评估了环境流量组分及水文情势变化。结果表明,1960~2016年间花园口站径流呈极显著减少趋势,减少速率为5.26×10^(8)m^(3)/a,并在1986年发生突变;环境流量组分较突变前变化明显,高流量事件(高流量脉冲、小洪水、大洪水)在流量量级、历时及频次3个方面均有所减少;低流量事件(极端低流量、低流量)突变后流量量级基本不变,但保持"持续时间短、发生频次高"的特点;径流变异后,花园口站各IHA指标均有不同程度的改变,水文情势综合改变度为59.99%,为中度改变;环境流量组分与水文情势变化受气候变化与人类活动共同影响,其中大型水利枢纽建设是主导因素。

In order to ascertain the changes of environmental flow components and hydrological regimes in the Middle Yellow River under changing environments, the Kendall rank correlation test, Mann-Kendall mutation test and cumulative anomaly method were used to analyze the runoff variation characteristics of Huayuankou from 1960 to 2016. On this basis, the IHA/RVA method was used to quantitatively evaluate the environmental flow components and hydrological regimes changes. The results show that from 1960 to 2016, the runoff of Huayuankou shows an extremely significant decreasing trend, with a decreasing rate of 5.26×10^(8)m^(3)/a, and abrupt change point occurred in 1986. The environmental flow components have changed significantly before the sudden change point, and high flow events(high flow pulses, small floods, and large floods) have decreased in three aspects of flow magnitudes, duration, and frequency;Low flow events(extreme low flows, low flows) have basically the same flow magnitudes, but maintain the characteristics of "short duration and high frequency". After the runoff variation, the IHA indexes of Huayuankou change in varying degrees, and the comprehensive change degree of hydrological regimes is 59.99%, which is a moderate change. Environmental flow components and hydrological regimes changes are affected by climate change and human activities, among which the construction of large-scale water conservancy project is the dominant factor.