Coupling coordination evaluation of “Three Waters” system and impulse response analysis in the Yellow River Basin

Abstract

The interaction and mutual influence of water resources, water environment, and water ecology play a crucial role in integrated basin water system planning and the harmonious development of a high-quality economy. In this study, a coupling coordination model was established to assess the development of coupling and coordination among water systems in the Yellow River Basin (YRB). By applying a Vector Auto Regression (VAR) model, it explores the influence mechanisms of key indicators on the sustainable coordinated development of the "Three Waters" system (TWS). Findings from 2005 to 2021 indicate a positive trend in the comprehensive development level of the YRB's TWS. The degree of coupling ranges from good to high-quality, and the coupling and coordination level progresses from near-dysfunctional to highly coordinated. Moreover, the study highlights the alternating effects of 104 yuan of GDP water consumption and wastewater treatment rates on the water resources-water environment system (WRS-WES); Sewage treatment rates and the greening coverage of urban built-up areas have significant and enduring promotional effects on the water environment-water ecology subsystem (WES-WELS). These insights lay the groundwork for the development of innovative ideas and strategies aimed at promoting the integrated and coordinated advancement of the TWS in the YRB.