Water Security Problem in North China： Research and Perspective

This paper addresses the emergence of water security problems in North China with the aim of highlighting key water resources management and water security issues for the long-term development of North China. Three key problems related to water resources and security issues in North China in the 21st century are addressed, namely 1） the water cycle under environmental change, 2） agricultural water saving, and 3） water security. Development of international research related to these issues is also reviewed. The research plan developed recently by the Chinese Academy of Sciences （CAS） is discussed and suggestions on research and development of water resources science in North China are presented. Thanks to focus on experimental catchments and dedicated research stations, a detailed knowledge of the water cycle on North China farmland has been compiled. A range of techniques that include isotope tracers has been used to acquire hydrologic data. Much research has been devoted to developing distributed hydrological models at different scales. In the well irrigation district, five different water saving irrigation regimes have been investigated, and these regimes have had widespread application, and reduced water use 60-150 mm while they increased water use efficiency （WUE） by 20%-30%. Furthermore, preventing water pollution is the most essential step to ensure North China＇s water security.