Abstract: Human-water system is a very complex giant system in which many factors are constantly changing, hence, the development and utilization of water resources should also be adapted to the ever-changing characteristics. However, it is not a passive or arbitrary adaptation, instead, it needs to follow certain rules and principles, in order to achieve a certain goal and apply the theory of adaptive utilization of water resources properly. Therefore, it is of great significance to study the issue of the adaptive utilization of water resources. Firstly, based on the theory of adaptive utilization of water resources which was proposed in the previous work, the paper analyzes the circular route of "confirm-adapt-evaluate-get feedback-reconfirm", which is the reasoning by which the author formulates the plan for adaptive utilization of water resources. Secondly, the paper proposes the application rules of theory of adaptive utilization of water resources. This includes following two laws, complying with four principles, undertaking three tasks and having four functions, which is the basis for judging how to apply the theory of adaptive utilization of water resources. Thirdly, the paper discusses the key issues of adaptive utilization of water resources, and puts forward some ways and prospects for further research. Finally, the paper takes the water source area of the middle route in the South-to-North Water Diversion Project as an example to illustrate the application prospect of theory of adaptive utilization of water resources. The study shows that adaptive utilization of water resources is a complex system engineering, it needs a whole set of theories and methods and needs to follow the evolution rule of water circulation system and the self-adaptive law of human-water relationship. Also, it needs to comply with the principles of not harming the function of water body, not exceeding the capacity of water resources regeneration, maintaining good water ecology and ensuring harmonious development of human-water relationship. In order to lay the foundation and provide a tool for the future research and application, further study should look into the criterion and quantitative methods, quantitative measurement and evaluation methods, optimal allocation model, planning method, forewarning evaluation and comprehensive regulation and control of adaptive utilization of water resources.

Key words: adaptive utilization of water resources(AUWR), the theory of adaptive utilization of water resources, application rules, human-water system, human-water harmony