The NASA Science Mission Directorate, Earth Science Division (ESD) has the primary responsibility for the application of NASA Earth science data with the objective to accelerate the use of results in applications that help solve problems important to society and the economy. The NASA mission statements include a clear focus on the Earth and life on Earth. NASA seeks to improve life on Earth by enabling people to use measurements of our home planet in valuable ways that help improve life. Within the NASA ESD, the Water Resources Program Element addresses concerns and decision making related to water availability, water forecast, and water quality (http://wmp.gsfc.nasa.gov). The Water Resources Program partners with government agencies, academia, private firms, and several international organizations. The emphasis has been largely on US applications. However, the program also supports international activities related to water scarcity and quality. There are numerous areas where the NASA Water Resources program will assist with water availability and quality issues. To account for these critical issues the program is structured in to four functional themes.

1) Streamflow and flood forecasting. Dramatic uses and issues from our world streamflow is occurring as a result of population increases, climate change and variability, increasing and changing agriculture needs, and hydro-energy requirements. For example, recent decreases in spring snow pack for many parts of the world yields lower summer streamflow with less water for allocation to numerous competing sources. In addition, a recent trend of more frequent heavy rainfall events throughout much of the world requires more pressing needs for improved flood forecasting and assessment.

2) Water supply and irrigation. Throughout much of the world, the primary need for water supply is for irrigated agriculture. Irrigation water requirements determined by evapotranspiration dictate the amount of water needed for agriculture. Water supply for the other societal needs is determined by a number of criteria, including snow pack, climate change, groundwater abstractions reservoir storage and rainfall-runoff processes. The primary focus of this NASA Water Resources theme is to use remote sensing and modeling products to estimate the amount of water loss through evapotranspiration from riparian and agriculture systems for river and reservoir management.

3) Drought. Drought is a normal and recurrent feature of climate. However, climate change data has indicated in a likelihood of an increase in droughts and drought severity for many portions of the world. There are various indicators of drought, and tracking these indicators provides a crucial means of monitoring drought. Understanding the historical frequency, duration, and spatial extent of drought also assists planners in determining the likelihood and potential severity of future droughts. The characteristics of past droughts provide benchmarks for projecting similar conditions into the future. NASA remote sensing and model products can provide an extremely important source of information for monitoring, and predicting the extent and duration of droughts. The NASA Water Resources Program supports several projects assessing the use of NASA remote sensing and modeling for drought monitoring and predictions. Most strongly support the U.S. National Integrated Drought Information System (NIDIS) and the associated Drought Monitor and Drought Outlook tools. Many of these activities have strong links to several international activities such as the Climate and Variability and Predictability (CLIVAR) program.

4) Water quality. The water quality monitoring and reporting requirements throughout the world are overwhelming in both the magnitude of the job and the specificity of the details. In addition, most of the water quality impairments to a watershed are caused by non-point sources such as from urbanization, agriculture nutrient and pesticide runoff, and forest disturbances. Remote sensing offers an underused technology for monitoring the water quality in our rivers, lakes, reservoirs, and watersheds. The NASA Water Resources Program is looking to expand its role in water quality through future solicitations. The program to date has supported work with the Group on Earth Observations (GEO) and support of nonpoint source water quality work using NASA satellite data with the Environmental Protection Agency. The program has plans to support water quality in particular through support of the Paul Simon Water Act for the Poor. The Act has an initial focus on developing countries to strengthen U.S. efforts on international water issues.

Other parts of the NASA Water Resources Program will be described, including: 1) Hydrology for the Environment, Life and Policy or ‘HELP'; 2) Latin American capacity building activities; 3) Regional Visualization Monitoring System (‘SERVIR') in Central America an East Africa; 4) downscaling of climate predictions for assessing hydrologic impacts; 5) technical support for water scarcity and quality issues associated with the Arab Water Council; and 6) hydrologic activities in evapotranspiration and the water balance in support of the Group on Earth Observations (GEO).