Evaluating water resources carrying capacity: The empirical analysis of Hubei Province, China 2008-2020

Scientific evaluation of water resources carrying capacity (WRCC) is the basis for implementing water resources conservation measures. Hubei Province, with the longest runoff mileage of the Yangtze River, the reservoir area of the Three Gorges Project and the core water source area of the South-to-North Water Diversion Middle Line Project, bears great responsibility for ecology conservation in China. How to evaluate WRCC in Hubei Province has become significant. This study created a WRCC evaluation method based on information entropy method, principal component analysis and Spearman's rank correlation coefficient to assess the WRCC in Hubei Province from 2008 to 2020. The available indicators were collected and summarized from the aspects of economy, population, resources and environment. By three-dimensionally displaying different indicators' eigenvalues of principal component analysis, the major indicators can be screened. Subsequently, information entropy method was applied to estimate WRCC in Hubei Province and Spearman's rank correlation was examined between WRCC and relevant factors. The results indicated that the WRCC in Hubei Province had been unstable in the range of 0.065 to 0.088 with the annual growth rate of 0.096%. It had a few peaks in year 2010, 2012, 2014, 2015 and 2016 while it decreased dramatically in year 2009, 2011, 2013, 2018 and 2020. Specifically, agricultural water use is more influential than industrial water use. The annual decline at 1.865% in agricultural water use is much smaller than the annual decline at 10.471% in industrial water use. Economically developed areas in the province have higher WRCC while economically backward areas have weaker WRCC.