Spatiotemporal assessment of water security in China: An integrated supply-demand coupling model

Water security is especially important for China who owns a huge population and has uneven temporal and spatial water resources distribution. Previous studies towards a comprehensive evaluation of water security issues at national or provincial level are still limited. In this study, a new supply-demand coupling model was proposed to evaluate water security situation more directly and comprehensively over China. The integrated supply-demand coupling model combines analytic hierarchy process, entropy weight method and fuzzy evaluation method and is particularly advantageous in handling complexity and uncertainty of water security measurement. The study result indicated that, from temporal dimension, China's overall water security situation has continuously improved, mainly because of the remarkable improvement of flood control capacity and water supply capacity. This is important to ensure China's own sustainable development goal. However, the ecological protection capacity was still highly insufficient, staying at an unsafe level for a long time; the security level of water resources and water ecology was still not optimistic and that of hydrological cycle was getting worse under the influence of human activities. From spatial distribution, the water security situation in the south part of China was generally better than that in the north. This study also highlighted the prominent water security problems in various regions, which provided a valuable reference for relevant authorities in their long-term water resources planning and management.