2011 Annual Report 1a.Objectives (from AD-416) To develop and evaluate a decision support tool for water management in the Nile River basin, using a combination of water balance modeling and remote sensing of evapotranspiration. 1b.Approach (from AD-416) Generate and evaluate remote sensing estimates of evapotranspiration (ET) and surface moisture stress (drought) over the Nile River Basin. In collaboration with NASA scientists, use remotely sensed ET to validate hydrologic predictions from the NASA Land Data Assimilation System (LDAS), customized to operate over the Basin, and to constrain assumptions of water diversion along the Nile. The validated LDAS output will then be integrated into the existing Nile Forecast System (NSF) and Nile Basin Decision Support System (NBDSS) and used for flood warning, reservoir management, and irrigation planning. 3.Progress Report Under this project, a time-series of maps of evapotranspiration (ET) generated using thermal satellite imagery are being generated over the Nile River Basin for integration into a hydrologic model, used to constrain estimates of water diversion in support of irrigated agriculture. Daily maps of ET at 6km resolution have been generated for 2007-2010. Monthly satellite-based ET agrees well with hydrologic model output, but additionally identifies enhanced ET over the irrigated Nile Delta, and over the Sudd Wetland.