Evaluation and Spatial Equilibrium Analysis of High-Quality Development Level in Mainland China Considering Water Constraints

Water resources are indispensable to human society. High-quality development (HQD) is a multi-faceted, demanding, and sustainable pattern. High-quality development level (HQDL) is an indicator of regional development. Its quantitative calculation is helpful to intuitively understand the current regional development situation, and helps departments make timely adjustments. Spatial equilibrium degree (SED) reflects the development balance among regions. Understanding spatial equilibrium can clarify regional development differences, promote the sharing of successful experiences, and then achieve common progress. Considering the current development and utilization situation of China's water resources, this study established an improved evaluation index system for HQDL, under water resources constraints. Then, we applied the proposed "single index quantification and multiple index synthesis and poly-criteria integration (SMI-P)" method to quantitatively evaluate the HQDL of China's 31 provincial-level administrative regions (PLARs), from 2010 to 2019. Finally, the calculation method of SED was employed to assess the SED of indicators and HQD in Mainland China. Results show that: (1) the HQDL of 31 PLARs showed a steady upward trend from 2010 to 2019. There were decrease tendencies from the coast to inland, and southeast to northwest in terms of spatial distribution, which shows that China's HQD has achieved remarkable results in the past 10 years, and the development of coastal areas is better; (2) The SED of HQD displayed a slow upward trend, and it has remained relatively stable after 2015, indicating that the spatial difference of HQD continued to shrink before 2015 and was relatively stable after that; (3) Water resource constraints played a significant role in well-developed areas, while the economic and social level was still the main constraint in medium and poor level areas. In addition, the spatiotemporal variation of HQDL, SED of HQD and indicators, and constraint effects of water resources on regional HQD, were fully discussed. Our findings not only provide new ideas for future research on HQD, but also possess great significance to China's HQD in the new era.