Geoscience Reference
In-Depth Information
It is plausible that the ecosystems in the ecoregions High Andes
,
Puna and both Scrublands, which provide basically food and fi ber for
local indigenous populations, can be severely disrupted by unexpected
biophysical perturbations and human interventions on them. For example,
local herders to raise livestock on natural grasslands in hills lying about the
Calchaquí valleys extend along the provinces of Jujuy, Salta, Tucumán and
Catamarca. Itinerant herders move about their livestock looking for better
forage; frequently they increase animal load beyond the carrying capacity
of a grassland, triggering an overgrazing episode that promptly leads to
the inception of erosive processes in communities prone to them because
they grow on structurally fragile soils (Molinillo 1993).
Vulnerabilities to Climate Change
The climatic trends detected over most of the country during the latest
four decades are likely consequences of global climate change (RA 2007).
Those trends have been more evident in some regions than in others,
presumably because high-quality climatic data was unevenly distributed
over the country's area.
Seven major climate vulnerabilities to plausible changes in temperature
and precipitation were identifi ed for the country, some of which are relevant
to the NOA and Cuyo regions. Each of these regions, however, shows
particular vulnerabilities to those climate variables (Table 21.2).
As to the future, changes in the global climate could have the following
impacts on NOA and Cuyo in the interval 2020-2040 (Table 21.3).
Plausible Biological, Physical, Economic and Social Impacts
Water is the regional resource to be mostly impacted by global warming.
National scenarios (RA 2007) show a clear connection between the
availability of water in the NOA and Cuyo regions and the increase in
temperature. As mountain rivers supply water for agriculture, energy
generation, and settlement needs, climate change is very likely to have large
economic and social impacts. The effi cacy of regional mitigation measures
to avoid water stresses is diffi cult to assess in view of the complexity of the
climate system and the dearth of dedicated studies.
Increased warming is likely to enhance the aridity of the region by
increasing evaporation, which in turn would make soils dryer and reduce
the levels of groundwater reserves. A relatively large part of the NOA
region High Andes
and Puna and all of Cuyo are under high to very high
water stress as measured by the (water) withdrawal to availability ratio,
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