Research on water resources supply guarantee in plain areas of Hebei Province based on the theory of dual water cycle

Water shortage is a major social problem facing China's development, and it is of great significance to make rational use of regional water resources and ensure the supply of regional water resources. Based on the theory of binary water cycle, this paper selected 15 indicators from the perspectives of water supply source, social water consumption and ecological health to form the evaluation index system of supply security, and used the comprehensive index method to evaluate the water supply security degree in Hebei Province from 2016 to 2023, and further analyzed the influencing factors of water supply security degree under the three years of abundance, average and drought. The results show that: (1) The water supply security degree in Hebei Province is generally increasing year by year, and the water supply source has a great impact on the water supply security degree. (2) The water supply guarantee degree in the wet year is greatly affected by the diversity of water sources, the water supply guarantee degree in the dry year is greatly affected by the natural water body, and the influence of various security factors in the normal water year is relatively even.(3) Regional natural water bodies are the bottom line of water resources security, and they are also the key to future water supply security. The results prove the feasibility of the theory of "dual water cycle" in the study of water supply security, clarify the law of water supply security in Hebei Province under the three types of abundance, flat and drought, and verify the objective fact that water resources are insufficient in Hebei Province.