黄河干流生态流量赤字及其成因

Ecological flow requirement deficit of the Yellow River and its key drivers

为准确核算和评估黄河生态流量,以黄河干流吉迈、唐乃亥、贵德、兰州、石嘴山、龙门、花园口和利津为研究对象,运用6种水文学方法分析生态流量过程,评估1956-2013年各断面生态流量赤字及其成因。研究表明:生态流量核算对方法选择较为敏感,其中Q90_Q50法的计算结果远高于其他5种方法;黄河干流8个断面的生态流量为(47±9)、(273±59)、(273±53)、(456±103)、(433±94)、(473±124)、(639±172)和(727±160)m^3/s,占天然径流量的36%~43%,其中5-11月占全年生态流量的70%~77%;在过去近60年,1985-2003年是黄河干流存在生态流量赤字最为严重的时期,吉迈、唐乃亥、贵德和兰州断面的生态流量赤字主要发生在枯水期,而石嘴山、龙门和花园口断面主要发生在丰水期,利津断面集中在上半年;人类耗水是造成生态流量赤字的最重要的原因,其次为气候变化。未来要加强用不同方法全面评估黄河干流、支流的生态流量,推动"精准"节水,完善水量调度方案,最大程度地减少生态流量赤字风险。

To accurately calculate and evaluate the ecological flow of the Yellow River,six hydrological methods are used to analyze the process of ecological flow and the ecological flow deficit and its causes of formation from 1956 to 2013 in Jimai,Tangnaihai,Guide,Lanzhou,Shizuishan,Longmen,Huayuankou,and Lijin stations.The results show that the ecological flow accounting is more sensitive to method selection,among which the results of the Q90_Q50 method are much higher compared to the other five methods.The ecological flow of 8 sections of the Yellow River is(47±9),(273±59),(273±53),(456±103),(433±94),(473±124),(639±172)and(727±160)m^3/s,accounting for 36%~43%of the natural runoff,of which May to November accounts for 70%~77%of the annual ecological flow.In the past 60 years,the most serious period of ecological flow deficit is from 1985 to 2003 in the mainstream of the Yellow River.The ecological flow deficit in Jimai,Tangnaihai,Guide,and Lanzhou sections mainly occurs in the dry season,while in Shizuishan,Longmen and Huayuankou sections mainly occur in the wet season,and Lijin section concentrated in the first half of the year.Human water consumption is the most important cause of ecological flow deficit,followed by climate change.In the future,it is necessary to comprehensively assess the ecological flow of the mainstream and tributaries of the Yellow River with different methods,promote"accurate"water conservation,improve water regulation schemes,and minimize the risk of ecological flow deficit.