Research on the supply-demand relationship of blue and green water and the evaluation method of deployable resources
Even in areas with relatively abundant water resources,there is still a contradiction between water supply and demand within them.Therefore,a research method was proposed in this paper for evaluating the supply-demand relationship and allocatable amount of blue-green water to effectively evaluate the supply-demand relationship within the watershed and provide theoretical support for corresponding resource allocation plans.Firstly,the amount of blue-green water resources at the sub watershed scale was simulated using the soil and water assessment tool(SWAT)model.Combined with human water use data,the blue-green water scarcity index was used to evaluate its supply-demand relationship.Then,based on different ecological flow standards,the supply-demand relationship of blue-green water in different areas within the watershed was divided into four levels,including good,balanced,slightly imbalanced and imbalanced.Finally,the amount of distributable water resources in areas with relatively abundant water resources was quantified.Taking the Wujiang River Basin as an example,the calculation results showed that the overall blue water scarcity index range of the basin from 2010 to 2019 was 0.47 to 0.81.The supply and demand relationship of blue water was good,and it could transport about 5.6 × 109 m3 annually to the outside blue water resources;The scarcity index of green water ranged from 0.89 to 1.01,indicating a relatively balanced supply-demand relationship.There were two sub basins with slightly imbalanced supply and demand of blue water within the basin,and one sub basin with imbalanced supply and demand of blue water.Nearly half of the sub basins were in a slightly imbalanced state of green water supply and demand,showing a spatial tension in the northeast and a good layout in the southwest,exposing certain hidden dangers.Under extreme drought conditions,a total of 9 sub basins in the basin had increased their water use risk levels,with 2 new sub basins in the southwest region experiencing supply-demand imbalance and an increased risk of blue water supply-demand imbalance.
SWAT modelblue green water resourcesWujiang River Basinsupply and demand balancewater resource allocation
万方数据
维普
