PROGRAM TITLE:  	Predicting Water and Energy Fluxes Within and 
From Managed Ecosystems
ACTIVITY STREAM:	Understanding
SCIENCE ELEMENTS:  	Climate and Hydrologic Systems

 U.S. DEPARTMENT OF AGRICULTURE
Agricultural Research Service

SCIENTIFIC MERIT:  Research emphasizes understanding of the hydrologic 
processes and the interactions between snow accumulation and melt, soil 
moisture and freezing, distribution of precipitation, evapotranspiration, 
groundwater recharge and stream flow.  Research will improve the accuracy 
of deterministic hydrologic models through the use of fundamental 
knowledge of hydrologic processes, new weather generation techniques 
incorporating elevation and spatial dependence of climatic variables, El 
Nino-Southern Oscillation, and other effects, and new technology including 
remote sensing, geographic information systems, and digital elevation data.  
Model improvements are accomplished by coupling results from additional 
field research and experiments with new technologies with new modeling 
approaches, and expanding cooperative efforts with other federal agencies.  
Data from ARS experimental watersheds, and SCS long-term precipitation 
and snow accumulation records, are used to modify, develop, and validate 
models.  Research results from this program also support TERRA (which is 
described in more detail in the USDA/ARS program on Ecosystem 
Modeling).

The Agricultural Research Service (ARS) maintains a sound foundation for 
developing the means for addressing problems of this type, including 14 
watershed research centers, water and energy data records exceeding 50 years 
at several locations and a strong core of scientific leaders developing and 
applying physically-based models for energy and water transfer in 
agricultural and rangeland systems.  ARS hydrologists are closely linked to a 
global network of other hydrologic scientists dealing with these issues, and 
are providing important leadership to major hydrologic modeling efforts.

STAKEHOLDERS:  The research benefits all of society through application of 
research results to insure food and fiber production for the Nation on a 
sustainable basis.

POLICY RELEVANCE:  This research is linked with USDA agencies (FS, 
CSRS, and SCS) and with other CEES agencies as opportunities present 
themselves.  Benefits will primarily be scientific information on which to 
develop policies and aid decision making at local, regional, and national 
scales involving the impact of climate and global change on the sustainability 
of food and fiber supplies and the health of the natural resource base.

PROGRAM CONTACT:  R. Dennis Child    Phone (301)  504-5618     FAX   
(301) 504-6231