Research progress of the anthropogenic influences on global freshwater cycle and the water planetary boundary assessment

Abstract

In recent decades, the effect of human activities on freshwater cycle transgressed the catchment scale. In order to solve the global and regional water problems effectively, a new framework is needed to transform from the traditional hydrology which focuses on catchment processes to the global-scale hydrology which focuses on the earth system processes. Based on the recent progress of global hydrology, this paper summarizes the patterns of anthropogenic effect on global freshwater cycle, reviews the framework of Planetary Boundaries for Water (PBW) and the research progress, and analyzes the possible approaches of freshwater management from the catchment scale to the global scale. Directed by the Earth system science, PBW pushes forward water cycle research to the global scale from the local and catchment scale, and evaluates the safe operating space of global freshwater use, with the aim to maintain the functions of the Earth system. The framework provides an important merit to evaluate the global sustainability of water resources. Water management should not only balance off the relations of water resources, ecological environment and socio-economic development locally, but also the relations of water cycle, Earth system functions and global sustainability. PBW is an important supplement to the watershed or aquifer management, and puts forward a new framework for the global and regional water management. In order to meet the demand of water management under the new system of natural resources management in China, the study of PBW should focuses on the following aspects: to establish global hydrological models and simulation and prediction platform on the basis of better understanding of global water cycle; to advance the study of relations between PBW and other planetary boundaries such as land use, biodiversity, and atmospheric CO2; to improve the double evaluation approaches (resource and environment carrying capacity, territorial development suitability) for territorial spatial planning with the framework of PBW.

Keywords

• earth system
• freshwater cycle
• planetary boundary for water
• regional scale
• global scale