Abstract
We examined the global warming impacts on the water resources of the Tone River Basin from the future projections of 9 GCMs (General Circulation Models) outputs under the IPCC SRES A2 and B1 scenarios. Moreover, we assessed the uncertainties in the global warming impacts by means of statistical test. As a result, temperature shows highly significant increases by 2080-2099 of about 4°C under A2 and about 2°C under B1, respectively. The magnitude of temperature increases under A2 is consistently higher than B1. But, the projections of precipitation are greatly different by GCMs, and the statistical significances are not shown clearly. Decreases in snow depth and in snow cover period are more remarkable under A2 than B1. As for the projections of river flow, some months appeared to have statistical significance while some months appeared to be no significance. Increase in river flow from December to March and decrease from May to June are highly significant. But, there is no significance for other months. Although increases of necessary reservoir storage volume are projected under A2 and B1 scenarios, the statistical significances are not indicated.
