黄河中游生态水文模型及洪旱灾害风险评估

Development of an eco-hydrological model for flood and drought risk assessment under a changing environment in the middle reaches of the Yellow River

黄河中游地区生态环境脆弱,易受到严重的洪旱灾害威胁。近年来,在大规模梯田建设和植被恢复工程等人类活动影响下,黄河中游水土流失治理水平稳步提高,发挥了消洪抗旱减灾的作用。但与此同时,黄河中游植被建设导致土壤干层加剧、产流产沙下降,增加了干旱风险;城市扩张也导致城市化地区孕灾环境剧变,暴雨洪水风险增加。目前针对变化环境下流域水文—泥沙—植被协同演变机理的认识还不够清楚,需要充分考虑工程扰动后流域水文—泥沙—植被重新建立新平衡的过程,科学评估大规模梯田建设、植被恢复工程和城市扩张等人类活动对洪旱灾害风险的影响,发展变化环境下黄河中游智慧化生态水文模型,预估大规模人类活动对洪旱灾害的长期后继影响,为黄河中游生态建设与水利工程协调发展有效防范化解洪旱灾害风险提供科技支撑。

The middle reaches of Yellow River basin,with a fragile ecological environment,are vulnerable to serious flood and drought disasters.In recent years,the controls on soil and water loss in the middle reaches of the Yellow River have been steadily improving under the influence of human activities such as large-scale terrace construction and vegetation restoration projects.These soil and water conservation measures play an important role in flood control,drought relief and disaster reduction.However,at the same time,vegetation construction in the middle reaches of the Yellow River has led to the intensification of dry soil layers,a decrease in runoff and sediment yields,and an increased hydrological drought risk.Urban expansion has also led to drastic change in this disaster-prone environment,including an increased rainstorm and flood peaks in urbanized areas,and increased flood and drought risks.In the middle reaches of the Yellow River basin,the hydrology,sediment and vegetation evolution is highly inter-connected and co-developed.With disturbance from human activities,a new hydrology-sediment-vegetation balance will form.At present,however,the co-evolution processes and mechanisms of the hydrology-sediment-vegetation balance in the basin under a changing environment is not clearly understood.The impact of large-scale distributed human activities such as terrace construction,vegetation restoration projects and urban expansion,on flood and drought disaster risks needs to be scientifically assessed.An intelligent eco-hydrological model of the Yellow River middle reaches under a changing environment should be developed to predict the long-term subsequent impact of large-scale human activities on flood and drought disaster risks.These improvements can provide scientific and technological support for the coordinated development of ecological construction and water conservancy projects in the middle reaches of the Yellow River,serving the effective prevention and mitigation of flood and drought disaster risks.