Environmental Engineering Reference
In-Depth Information
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Observations
Observations 4-yr filter
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NCEP precipitation
NCEP 4-yr filter
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Figure 5.7
Upper panel: wet season precipitation anomalies averaged over the 292 sites (black
line) and 4-year low pass filter (red line). Lower panel: wet season precipitation anomalies aver-
aged over NCEP (National Centres for Environmental Prediction) reanalysis data (black line) and
4-year low pass filter (red line). Reproduced from Ludwig
et al.
(2009), with permission
Due to the altitudinal limits of most Mediterranean mountain regions (average al-
titude 2800 m) they are often already close to the snow and ice limit. Any increase
in temperature according to current climate scenarios can significantly threaten the
reliability of the snow- and ice-fed resources. The ecological and economic buffer-
ing potential of the mountains increases from south to north and from east to west,
but the details of the impacts of climate change are still unknown. Since historical
times, the Mediterranean mountain water towers have played an unquestioned role
in the development of their forelands. Depopulation of the mountains is a major is-
sue that has impacted the present ecology and physical landscape (McNeill, 1992).
Many of the downstream communities, predominantly agricultural and touristic,
are already under extreme water stress and strongly dependent on highly variable
