This study is part of the larger Climate Assessment for the Southwest
(CLIMAS) Project sponsored by the National Oceanic and Atmospheric
Administration (NOAA) Office of Global Programs (OGP) and based at the
University of Arizona. CLIMAS combines the interdisciplinary expertise of
physical and social scientists in defining the entire range of human and natural
systems' vulnerabilities to climate variability for the U.S. Southwest.
Burton (1997) draws a distinction between climate variability and climate
change. He suggests that climate variability, or ‘normal climate’, is composed
of extreme weather events such as storms, droughts, blizzards, and other
phenomena. Climate change, on the other hand, entails an increased frequency
in the occurrence of such events. For the purpose of this study, climate change
is overly complex; thus we focus instead on climate variability.
Abundant summer rainfall does not contribute to aquifer recharge for two
reasons: first, high temperatures increase evaporation rates, which average 67
inches per year, and second, clay and silt layers that characterize the greater part
of the upper basins' fill impede downward percolation of water, making recharge from rainfall and irrigation water on the valley floor negligible (ADWR
Only one family in the SSV engaged in both farming and ranching on a commercial scale. Their neighbors refer to them as the ‘cowboy farmers’, indicating
the rarity of such a combination.
ALLBRITTON, D. L. and L. G. MEIRA FILHO. 2001. Climate Change 2001: The
Scientific Basis – Technical Summary. Contribution of Working Group I to the
Third Assessment Report of the Intergovernmental Panel on Climate Change.
Accessed on 2/15/2002 at http: //www.ipcc.ch/pub/wg1TARtechsum.pdf.
ARIZONA DEPARTMENT OF WATER RESOURCES (ADWR). 1994. Arizona
Water Resources Assessment: Inventory and Analysis. Department of Water
Resources Report, Volume I. Phoenix: ADWR.
AD J. 1991. A Legacy of Change: Historic Human Impact on
Vegetation in the Arizona Borderland. Tucson: University of Arizona Press.
KENNETH. 2000. El Niño and the Anthropological Opportunity. Practicing Anthropology 22: 20–23.
BRYANT, C. R., B. SMIT, M. BRKLACICH, T. R. JOHNSTON, J. SMITHERS,
Q. CHIOTTI, and B. SINGH. 2000. Adaptation in Canadian Agriculture to
Climatic Variability and Change. Climatic Change 45: 181–201.