Estimation of water demand of urban rivers and lakes in northern China based on multi-objectives and assessment of ecological benefits.Ⅱ.applications in the Beijing central urban area
In Part Ⅱ of this work the water demand estimation method developed in Part Ⅰ was applied to Beijing central urban area,to estimate water demand for rivers and lakes under"basic demand scenario"and"ideal demand scenario".Under"ideal demand scenario",increases in both velocity of river flow and water depth will significantly increase river water demand.Adopting a reasonable still water supply or lowering flowing water depth is an effective way to balance water use efficiency and large river water demand.Total water demand for the main rivers and lakes in Beijing central urban area under"basic demand scenario"and"ideal demand scenario"are 200 million and 1.08 billion cubic meters per year,respectively.Monthly water demand under"ideal demand scenario"shows significant seasonal variation,more in summer and less in spring,autumn,and winter.Water supply will increase surface area of rivers and lakes,to improve ecological quality of rivers and lakes and their surrounding areas.
central urban area of Beijingriver and lake replenishmenthabitat quality