ARS | Publication request: Global Analogues of Climate Change Effects on Agriculture and Groundwater Between Hydrologically Similar Regions of the World

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 15, 2007
Publication Date: June 24, 2008
Repository URL: http://www.gwclim.org/presentations/session4/green.pdf
Citation: Green, T.R., Bates, B.C., Charles, S.P., Fathelrahman, E.M. 2008. Global Analogues of Climate Change Effects on Agriculture and Groundwater Between Hydrologically Similar Regions of the World. Meeting Abstract.

Technical Abstract: Large regions of the world are heavily dependent upon groundwater for domestic water and irrigation. The impacts of climate change, including modified climate variability, on groundwater resources, soil water, agriculture, and human life are relatively unknown in most areas, and key sensitivities need to be explored. One low-cost approach is to identify and analyze geographical analogues between hydrologic/climatic regions. For example, hydrological similarities between Australia and South Africa have been identified previously [e.g., Fleming, 1995], and recently a bilateral partnership was formed between countries to collaborate on climate change adaptation [Turnbull and Schalkwyk, 2007]. Here, recent simulation results [Green, et al., 2007] from Mediterranean and humid subtropical regions of Australia are related to potential counterparts in Africa. Soil and vegetation play important roles in the infiltration, storage, and evapotranspiration of rainfall, which control the drainage of water beneath the root zone. In this way, the near surface biophysical system acts as a highly nonlinear transfer function of rainfall to groundwater recharge. Both the direction and magnitude of change in soil water and groundwater recharge may vary with projected climate change. Projected subtropical climate change likely will lead to pronounced increases in groundwater recharge. This could increase the amount of groundwater available for domestic and agricultural use, which may be needed to offset the increased demand for groundwater, especially if drought durations increase as projected in such regions. In addition to changes in the mean recharge rate, predicted climate change is expected to affect the temporal persistence of soil water content and interannual amounts of groundwater recharge. These subsurface responses to projected changes in regional climates have profound implications for water resources management and soil-water availability to agro-ecosystems. Likewise, results of a new investigation of climate change effects on agricultural systems in the semi-arid to subhumid Great Plains of the USA will provide analogues to similar regions around the world. Thus, international scientific research partnerships and collaborations between countries with regions of hydroclimatic similarity are recommended. In addition to simulation studies of the potential effects, long-term soil and groundwater monitoring should be encouraged for ground-truthing of the climate effects across geographical analogues.