Water resources in the Middle Rio Grande River Basin are increasing in demand for such diverse uses as agriculture, municipal and industrial, maintaining healthy habitats for endangered species, and recreation. Because of competing water demands, there is a critical need for rapid improvement in calculating and forecasting daily agricultural and riparian water consumptive use demands. Evapotranspiration (ET) from irrigated crops and riparian vegetation, and evaporation from open-water surfaces are the primary consumers of surface water in the basin. To address these problems, the U.S. Bureau of Reclamation (Reclamation) has developed and implemented the Agricultural WAter Resources Decision Support (AWARDS) system, an automated information system to assist water managers and users by providing easy access to rainfall and daily crop water use estimates. Building on the AWARDS system, Reclamation has been developing an Evapotranspiration Toolbox (ET Toolbox) which estimates the daily surface water use requirements at a resolution useful for implementation in Upper Rio Grande Water Operations Model (URGWOM).

The NASA Goddard Space Flight Center team has been developing a North American Land Data Assimilation System (NLDAS), which is characterized as a real-time, hourly, distributed, uncoupled, land-surface simulation system on a U.S. national domain at 0.125 (1/8) degree resolution. Recently, NLDAS has been enhanced through the incorporation of the Land Information Systems (LIS) modeling framework, and it has allowed NLDAS to be run at 1 km resolution and less. The main goal of this project is to apply NLDAS and remotely sensed products, like those of the MOderate Resolution Imaging Spectroradiometer (MODIS), to AWARDS and the ET Toolbox. Our aim is to improve our understanding of their contributions to the daily-weekly predictability of evapotranspiration (ET) of different vegetation types, open water evaporation, and bare soil conditions. NLDAS output will be compared and incorporated in to the Reclamation-developed ET Toolbox for the Middle Rio Grande area and evaluated with and without the new products. Water demand forecasting as addressed in this project is limited to the water demands from irrigated agriculture, riparian vegetation, and evaporation from open water surfaces. For the validation studies, observations from a growing network of meteorological stations in and around the basin will be used for comparison with the model forcing and state variables. In addition, other instruments like soil moisture probes and eddy covariance towers will be included at select sites for more point-based evaluations of the models' performance.