Analysis of characteristics and influencing factors of blue and green water resources in Lanzhou-Xining urban agglomeration based on WEP-L Model

Abstract

[Objective] The Lanzhou-Xining urban agglomeration, an important cross-provincial urban agglomeration in the upper reaches of the Yellow River Basin, features a fragile underlying environment and rapid urbanization. Therefore, it is necessary to conduct an in-depth analysis of the regional water resources. [Methods] A regional WEP-L model was constructed by comprehensively considering the natural and social aspects of the water cycle. Considering different hydrological years, and based on the concept of generalized water resources and water footprint theory, the current status and consumption of blue and green water resources in the Lanzhou-Xining urban agglomeration were quantified at both administrative region and sub-basin scales. The main influencing factors were then analyzed using the geodetector method. [Results] The results showed that the multi-year average water resource amount in the region was 176. 473 billion m³, of which green water resources accounted for 79. 14%. The proportion of agricultural water footprint to total water footprint in different cities ranged from 58. 45% to 99. 06%. Lanzhou had the largest industrial water footprint, reaching 0. 661 billion m³ in 2009. Lanzhou and Xining had relatively large domestic water footprints, and tourism significantly affected the domestic water footprint of individual sub-basins in Haibei. Altitude and total water supply were the factors with the strongest explanatory power for the regional blue and green water resource amount and the total water footprint, respectively. [Conclusion] The upstream area of the Lanzhou-Xining urban agglomeration is rich in water resources and has relatively low water consumption, making it suitable for establishing water resource protection areas, although tourism development management should be strengthened. Downstream cities should formulate development strategies based on the water consumption characteristics of different sub-basins and improve water resource utilization efficiency according to local conditions. The findings can provide a scientific basis for regional water resource management and allocation.

Keywords

blue and green water / water footprint / WEP-L model / geodetector / urban agglomeration / multi-spatial scale / Yellow River Basin / generalized water resources