Global water resources assessment under climatic change in 2050 using TRIP

Abstract

Annual water availability was derived from annual runoff estimated by land surface models using Total Runoff Integrating Pathways (TRIP) with 0.5° × 0.5° longitude/latitude resolution globally. Global distribution of water withdrawal for each sector in the same horizontal spatial resolution was estimated based on country-base statistics. Based on this framework, future projections of the global water resources considering population growth, climatic change, and the increase of water consumption per capita were carried out. Change in annual runoff was estimated based on the climatic simulation by a general circulation model coupled with TRIP. With the increase of population only, the future population under strong water scarcity, (water scarcity index is larger than 0.4), will increase by 90% in 2050 compared to the situation in 1995. Consideration of the climatic change due to global warming will relax this situation, and only 74% will be under strong water scarcity according to the future projection used in this study.