PROGRAM TITLE:  	Climates of Arid/Semi-Arid Regions
ACTIVITY STREAMS:	Process, Observations/Data Mgmt.
SCIENCE ELEMENT:	Solid Earth Processes


DESCRIPTION:  This program supports studies 1) to improve understanding 
of the relationship between climate, surficial processes, and vegetation cover 
in arid and semi-arid regions or in regions susceptible to future aridification, 
and 2) to define the extent and timing of past desertification.  Activities are 
focused on regions in the central and southwestern US and involve 
investigations of soils, wind-blown deposits, fluvial processes, and desert land 
forms.  Landsat imagery, airborne imagery, and radar are used in conjunction 
with ground-based studies and automated monitoring stations to inventory 
and monitor ongoing surficial processes, such as wind erosion, dust storms, 
and changes in vegetation and soils in response to short term climate change.  
Human populations and activities have expanded dramatically into arid and 
semi-arid regions of the US and other areas of the world.  The resulting 
changes in land use patterns, vegetation, and ecosystem disturbance, 
susceptibility of soils to wind erosion, and increased demands on water 
supplies are problems that could become even greater with changing climates.  
This program addresses concerns regarding the response of climatically 
sensitive regions to climate change and human activities.

Accomplishments include documenting the extent of wind-blown deposits in 
the central US, thus defining areas that are highly susceptible to wind erosion 
under current or slightly dryer conditions.  In addition 5 "GEOMET" desert 
climate monitoring stations in 5 different types of deserts in Arizona and 
New Mexico have been established.  These stations monitor climate change, 
surficial processes, and vegetation changes.

Selected Milestones:

FY 1994:  Complete report outlining major wind-blown sand transport events 
and intervals in the central US during last 10,000 years

FY 1994:  Complete digital shaded relief map of the western US (west of 100th 
meridian) as a base for mapping land surfaces that are highly susceptible to 
wind erosion.

FY 1995:  Incorporate GEOMET data into modeling wind velocity thresholds 
for different land surfaces, including variations in sediment type and 
vegetation cover.

Data and reports are peer reviewed and results are published in USGS reports 
or scientific journals.  This program is reviewed annually by an external 
panel of specialists from universities and other government agencies, and 
their recommendations are used to make program adjustments.  

STAKEHOLDERS:  USGS efforts are done in collaboration with investigators 
at NASA, NOAA, USDA, DOD (US Army) and several universities, 
including the University of Nevada and University of New Mexico.  

SHORT-TERM POLICY PAYOFFS:  Documentation of current and past 
interaction between surficial processes and climate variation in arid and 
semi-arid regions will allow identification of changes that are caused by 
human activities, and provide better estimates of the effects of anticipated 
future changes.  Identification of areas that are most susceptible to minor 
changes in climate or human activities will directly impact land use 

				Global Change Research Coordinator
				U.S. Geological Survey
				104 National Center
				Reston, VA  22092
				Phone (703) 648-4450
				Fax   (703)  648-5470