考虑水文变异的黄河干流河道内生态需水研究

气候变化及人类活动导致水文变异，变异前后样本总体分布显著不同，即改变了当地生态系统的水文状况，打破生态平衡。本文使用滑动秩和检验(Mann-Whitney U检验) 分析水文变异，并对水文变异成因做了系统的分析。在此基础上，对变异前各月平均流量序列用线性矩法推求GEV分布参数，求出概率密度最大流量，并将其视为相应月河道内生态流量。本文用该法计算黄河干流7 站各月河道内生态流量，即得河道内生态需水情况。分析表明，考虑水文变异的河道内生态需水计算方法是可行的；水文变异后，黄河流域干流各水文站满足生态需水的频率大大降低，汛期降低幅度比非汛期大；黄河生态系统水环境恶化的主要原因是人类活动。

Study of Ecological Instream Flow in Yellow River, Considering the Hydrological Change

Climate changes and human activities can lead to hydrological change. Distributions of the samples before and after hydrological change are significantly different. It means the local hydrological condition has changed, which breaks the ecological balance. We use moving rank sum test (Mann-Whitney U Test) to analyse hydrological changes and their causes. Then, L-moment is used to evaluate the parameters of generalized extreme value (GEV) distribution of the monthly flow series before hydrological change, and to calculate the maximum probability density flow, as the ecological instream flow. We use this method to calculate ecological instream flows of 7 hydrometric stations in the Yellow River Basin. The result shows that ecological calculating method which considers the hydrological change is practicable.