There is a critical need to improve water supply and demand forecasting for water resources managers in the Upper Columbia River Basin. The Bureau of Reclamation (Reclamation) teamed with the Land Data Assimilation System (LDAS) group at NASA's Goddard Space Flight Center (GSFC) to address this need. The objectives of the joint study include improving snowpack water supply forecasts, snowmelt runoff forecasts, and agricultural and riparian water consumptive use forecasts. The study integrates the improved water supply and demand forecasts into decision support tools to improve water resources management.

Reclamation is developing and implementing an evapotranspiration (ET) Toolbox in portions of the Upper Columbia River Basin for automatically inputting daily riparian and crop water use estimates, open water evaporation estimates, and WSR-88D-based rainfall estimates to RiverWare, which is a daily river modeling and accounting system for decision makers. The rainfall estimates, as well as cool season precipitation estimates, are from the Reclamation-developed Precipitation Accumulation Algorithm (PAA). Recently consumptive use forecasts out to 72 hours have been added to the ET Toolbox. These forecasts are based on the NCEP Eta model (12-km grid) weather forecast parameters. This water resources decision support system is being used operationally.

The NASA GSFC LDAS group is heavily involved in the development and testing of the uncoupled North-America Land Data Assimilation System (NLDAS). The NLDAS uses four physically-based, land-surface models (LSMs) running on a common grid and driven by common surface forcing and observation-based precipitation and radiation fields. The study approach for the Upper Columbia River Basin is to incorporate NLDAS products into the ET Toolbox and RiverWare. Upon integration, then evaluate the resulting products and value added to the water operations in terms of additional conservation storage, and sustainable river basin ecosystems. There are two ways in which collaboration efforts between the LDAS team and Reclamation have to be made, viz., (1) the exchange of data to help each other evaluate the ability of the current LDAS and its suitability to fit into Reclamation's water management operations and decision support tools, and (2) through such validation, the LDAS team's main goal is to improve the parameterization and land surface model physics, incorporating the scaling issues, to render better output specific to Reclamation's water supply and demand forecasting needs. On the applications side, Reclamation's main goal is to improve water resources management through the development of decision support tools like the ET Toolbox and RiverWare.