Project background: Moisture is the most active factor in the earth’s surface system, which is driven by natural and human activities. Identifying the crossfeed action mechanism between terrestrial hydrological cycle and global change and accurately describing and simulating the evolution of global terrestrial hydrological cycle and its resource, ecological and environmental effects are not only the key support for global climate governance, but also the urgent need for China to understand the water security and water resources of all parties in international climate negotiations and strive for initiative.
Main content: Study on “influence mechanism of natural and human activities on the terrestrial hydrological cycle in the earth system”, “mechanism of action of terrestrial hydrological cycle in the earth surface system on global change”, “construction of land-hydrological coupling model and prediction of the evolution trend of global terrestrial water resources” and “evolution and trend prediction of drought and flood events under the background of global change”. Solution to three scientific problems, including “global terrestrial hydrological cycle process and flux evolution mechanism in the ‘natural-artificial’ dual driving mode”, “mechanism of action of terrestrial hydrological cycle on global change” and “evolution mechanism of global terrestrial water resources, drought and flood events”.
Main scientific and technological innovations and contributions: manual digitizing and calibration of first-level to fourth-level river network based on Google earth in the world; construction of river and water resources area coding methods based on river network topological relationship; evaluation of water resources quantity of first-level to fourth-level streams in the world based on relationship between precipitation and runoff.
Achievement and scientific and technological output: 131 papers have been published (received included), 91 of which were SCI; 88 patents have been applied and 39 patents have been authorized (1 international patent, 15 invention patents and 18 patents for utility models); 11 of the project backbones were awarded national/provincial honorary titles; 7 provincial and ministerial awards were obtained under the support of this project and related projects; 3 people were promoted and 17 postgraduates were cultivated; participated in more than 10 international academic exchanges and provided policy consultation and advice twice.
Economic benefits: The proposed water resources allocation schemes and major measures for the whole country and key areas, aiming at gradually eliminating water resources overload areas, will provide important support for the national water resources security and economic industry planning decision-making and will be the smooth water resources foundation for the national new urbanization and “Two Hundred Years” strategic objectives. Among them, the bearing capacity evaluation method and monitoring and early warning technologies for water resources provide direct support for the establishment of national water resources bearing capacity monitoring and early warning mechanism.
Social benefits: The proposed overall management and control strategy of national water resources based on bearing capacity evaluation and strategic allocation will lead and promote the reform of China’s water resources social governance system and institutional change. The established large data platform of water resources bearing capacity will also play an important role in the practice of water-related public services and social management.
Environmental benefits: The first proposition of national water circulation budget and bidirectional flow chart of circulation system elements balance has great practical significance for us to understand our water resources and plan and manage water resources scientifically. The proposed bearing capacity evaluation results of water resources in different counties in China, prediction of water resources pressure in China in the future and identification of risk factors will form a systematic and objective cognition of water resources situation in China as a whole.
Ecological benefits: Firstly, the national regional water quantity, water quality, water flow, elastic threshold of water space and parameter set proposed in the project will gradually become the boundary of regional water resources development and utilization and water cycle regulation, which will help to promote the establishment and improvement of the national water ecological red line system; secondly, the national water resources allocation and regulation based on load balance will promote the gradual elimination of different types of water resources overload areas, including the satisfaction of ecological water demand process of rivers and lakes, restoration of groundwater level, protection of river beaches, wetlands and other water space and so on, so as to support the normal growth of regional vegetation and protection and restoration of aquatic biodiversity.