Keynote Address:Global·water Resources Assessment and Future Projections

JIRCAS international symposium series
ISSN 13406108
書誌レコードID(総合目録DB) AA1100908X
Anticipated water scarcity in the first half of this century is one of the major causes for concern among international issues. However, even though the issue has an international impact and worldwide monitoring is critical, the number ·of global estimates at present and future projections are limited.
In this study, annual water availability was derived from annual runoff estimated by land surface models using Total Runoff Integrating Pathways (TRIP) with 0.5° by 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 statistics of municipal water use, industrial water use, and agricultural intake, using global geographical information systems with global distribution of population and irrigated crop land area.
Although the total population under water stress estimated for 1995 corresponded very well to former estimates, the number highly depended on how to determine the ratio indicating how much water from outside of a region can be used for water resources within a region. This suggests the importance of regional studies for evaluating the possibility of water intake as well as the validity of the investment for water resources withdrawal facilities.
Based on the assessment of the current situation, projections for 2050 were derived considering the effects of climate change and population growth. The effect of climate change on water resources was. derived from the changes in runoff in a global warming simulation conducted by the Center for Climate System Research, University of Tokyo. The population growth followed the scenario developed by the United Nations.
As a result, water resources and water stress in 2050 were estimated. The changes in the geographical distribution of water stress between 1995 and 2050 did not seem to be apparent at a glance. However, instead of obvious changes, the projection indicated that the regions affected by severe stress in 1995 will experience more severe stress and that these regions will spread to neighboring regions. It can be argued that water scarcity has already been emerging in certain regions in the world and such regions themselves might face a more serious situation in the future , and that population growth in the future will exert a major effect on water scarcity compared to climate change.
作成者 Katumi Musiake Taikan Oki Yasushi Agata Shinjiro Kanae
公開者 Japan International Research Center for Agricultural Sciences
言語 eng