Study on the coupling model of urbanization and water environment with basin as a unit: A study on the Hanjiang Basin in China

Abstract

The urbanization process of the Hanjiang Basin is speeding up and facing many challenges. It is necessary to take active actions to realize the balance between urbanization development and water environment protection. This paper aims to establish a comprehensive evaluation model of urbanization and water environment (UAWE) and explore the development of UAWE in the Hanjiang Basin in China from 2010 to 2018. In terms of methodology, these evaluation models are combined with the Coupling coordination degree model (CCDM), Exploratory Spatial Data Analysis (ESDA), and Geographically and Temporally Weighted Regression (GTWR) to measure and analyze the coupling degree (CD) and spatiotemporal heterogeneity of UAWE. Our findings include the following: (1) From 2010 to 2018, in all regions of the Hanjiang Basin, urbanization showed a gradual upward trend. Among Them, the comprehensive urbanization index (CUI) of Xiangyang increased by 25.37%. (2) The comprehensive water environment index (CWEI) presents a fluctuating growth, with the rate of increase in Jingmen's reaching 17.44%. (3) There is heterogeneity in time and space between cities in the Hanjiang Basin, and the positive interaction effect of UAWE is mainly focused on the middle and lower reaches of the Hanjiang River. (4) Coupling coordination degree (CCD) in the basin shows an increasing trend, and the areas with high CCD are mainly concentrated in Xiangyang and Xiantao. (5) ESDA shows that the CCD among cities in the basin has spatial correlation and heterogeneity, and the regions with similar CCD tend to be distributed centrally in space.

Keywords

• Urbanization
• Water environment
• Coupling coordination degree model
• GTWR
• ESDA
• Hanjiang Basin