Dynamic evolution of spatial equilibrium degree of water resources composite system in system-region two stages: The case of Lianshui Basin, China

Abstract

The water resources in Lianshui Basin is facing a prominent contradiction between production and ecology, as well as fierce competition among various regions. However, existing researches on spatial equilibrium typically tend to address only one of the dimensions among water resources system and other systems or among different regions, which can not meet the requirements for optimal allocation of water resources aiming for spatial equilibrium under the high-quality development strategy. The definition and quantitative evaluation method of spatial equilibrium remain unclear. In order to respond to the policy of spatial equilibrium and overcome the dilemma of water resources development and utilization under the new normal, the connotation of spatial equilibrium at two levels of system and region was presented, a quantitative dynamic evaluation method for the spatial equilibrium degree in system-region two stages was proposed in this study. A comprehensive evaluation indicators system was built for the water resources composite system composed of three subsystems: water resources, social economy and ecological environment, and a dynamic quantization model of coupling coordination degree based on the comprehensive evaluation indices of three subsystems was established, the temporal and spatial dynamic evolution process of the coupling coordination degree of water resources composite system was analyzed. At the same time, Theil index was used to research the dynamic evolution characteristics of the regional difference in coupling coordination degree in Lianshui Basin. This paper also identified the main source of difference based on the decomposition of Theil index, and the degree and trend of spatial equilibrium of water resources in Lianshui Basin were comprehensively analyzed. The results showed that the coupling coordination degree of the composite system of each district in Lianshui Basin was continuously improving, but there was no significant trend in the difference of coupling coordination degree among regions, which means the degree of spatial equilibrium in the “system stage” has notably improved, but the degree of spatial equilibrium in the “region stage” had no significant and stable increase. In addition, the difference within the region was always the main reason for the deficiency of spatial equilibrium.