Abstract
In the Aral Sea Basin, serious drought was induced by huge-scale irrigation projects. Toward sustaineble water management, impacts of climate change on water resource and water demand should be quantitatively estimated to provide a scientific basic information for the rational planning.
In this study, terrestrial water circulation model was applied to project future water resource and demand. It is mainly consist of land surface model SiBUC (Simple Biosphere including Urban Canopy). In its irrigation scheme, local irrigation rule was reflected through in situ measurement on testing farms in Uzbekistan and furrow irrigation can be considered which is generally selected in this basin. The meteorological data for the model input are from Meteorological Research Institute atmospheric general circulation model (MRI-AGCM3.2S) based on A1B scenario. Spatial resolution is about 20km and time resolution is one hour. Since the GCM projected that both temperature and precipitation will increase in the whole basin, future drought situation should be quantitatively analyzed by physical model.
As a result of the analysis, water resource will not change since increment of precipitation will consumed by evapotranspiration increase and little water will additionally flow out as surface runoff. On the other hand, water demand will increase due to temperature rise especially in the arid region. In the limitted area in mountainous region, precipitation increase reduces water demand for irrigation. Comprehensively, drought situation in this basin will increase under the future climate.
