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.
Under this project, a time-series of maps of evapotranspiration (ET) generated using thermal satellite imagery have been generated over the Nile River Basin, to serve as an independent estimate of water use and water diversion in support of irrigated agriculture within the basin. Year 3 activities involved a quantitative intercomparison of these thermal satellite ET products with estimates generated with a land-surface model based on water balance, and with other satellite-derived ET products available over the region. Results from this intercomparison have been submitted as a manuscript to a peer-reviewed journal, and demonstrate the ability of the thermal-based retrieval to capture critical water use features that are missed by the other mapping approaches, including enhanced ET over irrigated areas and wetlands.