Spatial Difference And Regional Division Of Water Usein Yangtze River Delta Based On Efficiency

Yangtze River Delta is one of the most developed and urbanized areas in China,however,with its rapid development,water demand grows at the same time.Since 2000,Water-Saving Society,the Strictest Water Resources Management System and other water regulations have been made to set exact constraint objectives on water consumption,water use efficiency and wastewater discharge respectively.Considering a relatively weak constraint on water consumption in Yangtze River Delta,control on water use efficiency and wastewater discharge is of great importance.Based on water use efficiency,this paper intended to quantify spatial difference and study on its influencing impacts,then carried out regional division both concerning water consumption and wastewater discharge.Main conclusions are as follows:(1)This paper introduced a difference-quantifying tool,which used to calculate income difference,to quantify spatial difference of water use efficiency in Yangtze River Delta.By constructing Water Lorrenze Curve,Water Gini Coefficient was calculated,demonstrating the degree of spatial difference.The results showed that Water Gini Coefficient increased from 0.10 to 0.19 during 2000 and 2010,demonstrating a growing trend of larger spatial difference.However,between 2010 to 2015,Gini Coefficient maintained aroung 0.19,showing that there was no obvious change in spatial difference of water use efficiency.Based on Theil Index,difference in economic growth between cities was the main contributor for growing spatial difference from 2000 to 2010.(2)Based on statistics,this paper discussed the impacts of water use efficiency on total water consumption.It was found that as GDP growed by 632.00%,the total water consumption only increased by 19.86%,and it increased slowly with fluctuation.Increasing water use efficiency was the main contributor.However,through scenario analysis,though water use efficiency raised continuously during 2000 and 2015,the conservation volume owing to water use efficiency enhancement still cannot counter the increasing water demand from economic development.Thus,water use efficiency should be a focus of future water managemtn in Yangtze River Delta.(3)Given that there exsited spatial difference of water use efficiency,this paper,by comparing the growth ratio of water use efficiency and economy,divided the 26 cities of Yangtze River Delta into three different types,namely Prioritizing Water Conservation Type,Prioritizing Wastewater Reduction Type,Water Conservation and Wastewater Reduction Type,and corresponding suggestions on water management were made.