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Impact of climate change on the hydroclimatology of Lake Tana Basin, Ethiopia
Author(s) -
Setegn Shimelis G.,
Rayner David,
Melesse Assefa M.,
Dargahi Bijan,
Srinivasan Raghavan
Publication year - 2011
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2010wr009248
Subject(s) - environmental science , climate change , precipitation , streamflow , tributary , drainage basin , climatology , water resources , structural basin , water balance , gcm transcription factors , swat model , soil and water assessment tool , hydrology (agriculture) , climate model , general circulation model , geography , geology , ecology , meteorology , oceanography , cartography , geotechnical engineering , paleontology , biology
Climate change has the potential to reduce water resource availability in the Nile Basin countries in the forthcoming decades. We investigated the sensitivity of water resources to climate change in the Lake Tana Basin, Ethiopia, using outputs from global climate models (GCMs). First, we compiled projected changes in monthly precipitation and temperature in the basin from 15 GCMs. Although the GCMs uniformly suggest increases in temperature, the rainfall projections are not consistent. Second, we investigated how changes in daily temperature and precipitation might translate into changes in streamflow and other hydrological components. For this, we generated daily climate projections by modifying the historical data sets to represent the changes in the GCM climatologies and calculated hydrological changes using the Soil and Water Assessment Tool (SWAT). The SWAT model itself was calibrated and validated using the flows from four tributaries of Lake Tana. For the Special Report on Emissions Scenarios A2 scenario, four of the nine GCMs investigated showed statistically significant declines in annual streamflow for the 2080–2100 period. We interpret our results to mean that anthropogenic climate changes may indeed alter the water balance in the Lake Tana Basin during the next century but that the direction of change cannot be determined with confidence using the current generation of GCMs.