Interactions between water use efficiency and urbanization level in the Beijing-Tianjin-Hebei megaregion, China

To reveal the the contradictions between sustainable development and water availability,it is necessary to conduct in-depth analysis of the interactions between urbanization level and water use efficiency between cities in BeijingTianjin-Hebei megaregion.In this study,we took the Beijing-Tianjin-Hebei megaregion as a case and used the super efficiency data envelopment model to evaluate water use efficiency during the period of 2006-2015,and then explored the interactions between urbanization level and water use efficiency.The main results were:(1) from 2006 to 2015,the domestic and industrial water use efficiency decreased slightly,whereas the efficiency of agricultural water use increased significantly;There existed obvious difference on water use efficiency between cities,i.e.,water use efficiency of all industries were high in Tangshan,Hengshui,and Cangzhou,but low in Xingtai and Handan;(2) the impacts of urbanization level on water use efficiency varied between cities.Urbanization development could significantly increase the domestic water use efficiency,while it had different extent of negative impacts on industrial and agricultural water use efficiency.The comprehensive water use efficiency was only significantly related with economic urbanization level(R2=0.19),indicating that further adjustment of economic structure would be effective to improve water use efficiency;(3)overall,by the comparison of urbanization level and water use efficiency,most cities didn’ t match.There were only 4 matching cities,accounting for 30.77% of the numbers of cities in Beijing-Tianjin-Hebei megaregion.Moreover,there was no city with both high urbanization level and high water use efficiency,indicated that it was essential to improve the matching status.Regarding the unbalanced interactions between urbanization levels and water use efficiencies,more attention should be paid to promote the water use efficiency,such as optimize the input-output structure and explore some water saving development models.