Theoretical framework of dualistic nature–social water cycle

The global climate change and intensification of human activities in recent decades have made profound changes in hydrological cycle processes and water resources,and produced serious water problems and water crisis in many areas.The main reason is that the driving force of water cycle,the structure of water cycle,and the parameters of water cycle have dualistically evolved under the influence of human activities,and consequently resulted in reduction of runoff water resources,water pollution,and degradation of natural ecosystems.In order to realize of the safety aim of water supply,water environment,and ecosystem in area which is short of water resources,scientific regulation of water resources must take basin water cycle system as the unified base,and the first scientific basis is the awareness of the internal mechanism and law of water cycle evolution under highly intensive human activities.This article discussed four aspects of dualistic water cycle evolution,including its history in China,its theory,its characteristics in a typical basin,and its description of integral structure,along with the conceptive model system to quantify it.This article can be a reference to the basic cognition of water cycle evolution in a changing environment,and the study of water resources reduction reasons in the contemporary age.