Spatial-temporal differentiation pattern and influencing factors of high-quality development in counties: A case of Sichuan, China

High-quality development (HQD) is a development model proposed by the Chinese government in the regional development process, with the five major development concepts of innovation, green, coordination, openness and sharing as its core. It is an expansion of sustainable development, incorporating the connotation of green development and emphasizing the joint promotion and coordinated development of the five subsystems. This study takes the counties in Sichuan, China, as the case area, constructs an evaluation index system based on the five development concepts, conducts research on the endogenous coordination of the HQD system through the Coupling Coordination Degree model. On this basis, its spatial-temporal differentiation characteristics are characterized by Getis-Ord Gi*, and the key influencing factors of the regional HQD are identified by Geographical Detector. The results indicated that the HQD coupling degree in Sichuan Province was in a highly coupling state, but the coupling coordination degree was at the primary coordination state, and the level of HQD was relatively low. Moreover, a spatial characteristic of "high east and low west" was showed in the HQD coupling coordination degree of Sichuan Province. Taking Chengdu City as the agglomeration center, it showed obvious agglomeration effect, and the HQD coupling coordination degree in the areas around Chengdu were significantly higher than in other areas. Furthermore, the permanent populations per unit area, the road mileage per capita, the number of employees and the proportion of fiscal expenditure to GDP had significant effects on HQD. The experience of the case area can be a reference for other similar regions globally to promote their highquality economic and environmental development.