Research framework of drought-food cascade effect based on water cycle processes
Under the background of climate change and the increasing impact of human activities,it is urgent to realize precise preventive control against drought and flood disaster risks.Research progress of drought and flood events was reviewed from the aspects of preparation mechanism,propagation mechanism,event evaluation,risk assessment,and impact effects.The current deficiencies in the evolution mechanism and the construction of evaluation indicators of drought and flood events were clarified.Essential connotation,impact effect,and evaluation methods of drought and flood events were analyzed from the perspective of the dualistic water cycle and its associated processes at four scales(slope,riverway,watershed,region)and two aspects(water volume and effects).Based on the hydraulic connections between surface-soil-underground,slope-river,tributary-main stream,and water network engineering,the internal relationship between drought and flood at different spatial scales is analyzed from the aspects of water volume and effects.It is clarified that drought,floods,and the cascading processes of drought and flood are essentially influenced by the regulation and storage effect of the watershed.From the aspects of connotation,type,form,and key technologies,the research framework of the drought-flood cascade effect is proposed.It is necessary to quantify the changes in regulation and storage capacity of various elements at different spatial scales from the perspective of basin regulation and storage effects to prevent and resolve drought and flood disaster risks.