Evaluate cities' urban water resources system resilience along a river and identify its critical driving factors.

Abstract

The emergence of a series of problems, such as serious water environment pollution and flood disasters, leads to an increase in an urban water resources system's vulnerability and pressure. In order to alleviate an urban water resources crisis, calculating the water resources system resilience (WRSR) and identifying its impact factors are essential. This paper constructed a resilience evaluation framework of the "Economy-Social Development-Infrastructure-Water Resources-Ecological Environment" water resources system from three stages, i.e. resistance, restoration and adaptability. Then, taking 21 cities along the Yangtze River Economic Belt's lower reaches (YREB's lower reaches) as an example, we scientifically measured the WRSR by using the Projection Pursuit Evaluation Model of Real Coding based on the Accelerating Genetic Algorithm (RAGA-PP) and analyzed its driving factors with Geographic Detectors (GD). (1) From 2010 to 2018, the overall level of the WRSR along the YREB's lower reaches was low, and it was characterized by attenuation from central cities to marginal cities; Suzhou had the highest average WRSR (0.656), while Chizhou had the lowest (0.207). (2) From stage characteristics, compared with 2010, resistance and restoration of most cities along the YREB's lower reaches showed an upward trend in 2018; however, the adaptability level of some cities was still low. From the perspective of sub-system resilience, resilience levels of different sub-systems in each urban water resources system (UWRS) were different. (3) For impact factors, average factor interpretations of per capita GDP, average wages of employees and affected areas of floods, geological disasters and typhoons were largest. Based on this, this paper provides relevant suggestions for improving the WRSR along the YREB's lower reaches to improve ability of UWRS to resist external risks.