Environmental Engineering Reference
In-Depth Information
important to take into account the possible effects of changing snow seasonality,
changing absolute quantities of snowmelt as well as loss of discharge due to in-
creasing river impoundment by dams. Apart from changing discharge regimes, the
effects of sedimentation of dam reservoirs will strongly influence the distribution
of water resources available for hydropower energy, irrigation, vegetation and hu-
man consumption. Demand for electricity through hydropower will increase with
a growing population and industry, so that uncertainty about reservoir filling levels
will increase in the future. Water demand for agriculture, in particular for export
crops, is also expected to grow. Possible earlier snowmelt occurrence will reduce
the availability of water during the summer period when water demands are partic-
ularly high. The consequent increased sediment entrapment in the dams will have
significant impacts on the sediment and nutrient transport to the deltas, enhancing
coastal erosion and loss of wetlands. Parallel to this, export of virtual water (the
volume of freshwater used to produce a product, measured at the place where the
product was actually produced - Hoekstra, 2003) from the Mediterranean region
is likely to increase, for citrus fruits and dates for instance, whilst the regional dif-
ferences will possibly become larger (Hoekstra, 2003). Moreover, peaks in energy
and water consumption by tourism during the spring and summer will add to the
burden on the available water resources. Since the highest water consumption is
for agriculture, it is important to establish the dependencies of snowmelt discharge,
rainfall-runoff and agricultural practices for different basins in the future.
5.2.6
Tourism and hydrology
Water supply and tourism is an issue of concern not only in the coastal fringes of the
Mediterranean (for hotels, swimming pools, golf courses, etc.) but also increasingly
in the mountain catchments. As for the Alps, water supply in the Mediterranean is
naturally limited at higher altitudes due to limits in catchment surface area, discon-
tinuity and limitations in size of groundwater reservoirs, high infiltration rates due
to high permeability, low discharge of zero- or first-order streams and lack of natu-
ral surface storage areas. However, increasing amounts of water are being used for
tourism and snow-making in the upper parts of mountain catchments (de Jong
et al.
2009a). Virtually all Mediterranean mountain ranges or peaks with skiing facilities
now produce artificial snow (Figures 5.5 and 5.6). Apart from the Mediterranean
Alps, these include the Pyrenees, Lebanon, Israel and Turkey. This requires the per-
manent availability of large amounts of water (three times more water per hectare
than that used for the irrigation of maize). Water is either pumped directly from
streams or stored in large water storage reservoirs, usually at around
+
4
◦
C. It is
increasingly difficult to fill these reservoirs with locally available water, therefore
transfers from local streams, valley bottoms or interbasin transfers are becoming
more common. Such transfers do not take place without impact on the local ecology,
hydrology and soils. In the source areas where water is captured it causes a water
deficit, whereas in the destination areas a water surplus arises. Some resorts in the
