Climate, Climate Variability and Impacts in the Mediterranean Area: An Overview
19
overall effect is small because the various actions compensate each other, but it is
also very likely that regionally the water cycle may be enhanced where water is
spend and aridity will increase where water is withdrawn. There is no doubt that in
many areas the soil moisture deficit increases during the dry summers due to
overexploitation ofthe water resources. Because of the long distance water transfers
made possible by modern techniques (or the revi val of the old practice of aqueducts)
a change of regional precipitation often is not the alone a measure for a sustainable
development. Therefore the prediction of precipitation changes by models without
an efficient soil parametrization and without taking into account water transfers in
natural as well as artificial aquifers do not represent adequately regional
idiosyncrasies.
The growing European Union with its diversity of agricultural conditions
enforces a redistribution of food production and a new structuring of the land-use.
An overriding issue is the conservation and useful distribution of water. The storage
of water of the wet seasons for use during dry intervals got large priority and the
constructions for this purpose range from big dams, drilling projects and long
aqueducts to small private ponds. The impact these new water surfaces have on
regional climate is difficult to estimate. At the one hand these water resources allow
the irrigation oflarge areas in which the land surface properties are changed and on
the other hand the ground water level in adjacent areas is lowered by the
concentration of the water. A study was carried out by the Turkish Department of
Meteorology of the impact of the southeastern Anatolian irrigation project on
regional climate. The project is composed of 22 dams (19 hydroelectric power
plants) with a total irrigation area of 1. 7 10 6 ha which would affect an area of7 4.000
km 2 when completed in 2010. So far no significant signals could be detected in both
long term temperature and precipitation data. The statistics of extreme events on the
other hand shows an increase of high temperatures and an decrease of low
temperature but no effect was detected in the precipitation. In 1992 the low
temperature periods were at an extreme of 33 cases (Halpert et al., 1993). Model
simulations indicate an increase of the precipitable water in the lower levels ofthe
atmosphere COnal, Karaca, and Dalfes, 2000).
Another factor is the competition in the production offield fruits. In many places
cultures are planted to obtain an economic advantage though looking at the totality
of the European production and the import from elsewhere in the world these
products are partly superfluous. They are also quickly changed if the production
becomes unattractive respectively if subventions are cancelled. In this connection it
is interesting to note that in parts of the Ottoman empire, e.g. Palestine, because of
the taxation of trees these by the time vanished completely (Wagner, 2001, p. 230):
"Political ecology" obviously played an important role since ever. In Italy some areas
such as Ie Crete (SE of Siena) which were abandoned are taken under the plough
again to grow grain. In Spain as well as in Italy rocky land is made available for
agriculture again by smashing even large stones with big machines. Urbanization
is growing in coastal areas and land is transformed to generate an environment for
tourism. Fortunately a growing number of "natural parks" are conserved.
19
overall effect is small because the various actions compensate each other, but it is
also very likely that regionally the water cycle may be enhanced where water is
spend and aridity will increase where water is withdrawn. There is no doubt that in
many areas the soil moisture deficit increases during the dry summers due to
overexploitation ofthe water resources. Because of the long distance water transfers
made possible by modern techniques (or the revi val of the old practice of aqueducts)
a change of regional precipitation often is not the alone a measure for a sustainable
development. Therefore the prediction of precipitation changes by models without
an efficient soil parametrization and without taking into account water transfers in
natural as well as artificial aquifers do not represent adequately regional
idiosyncrasies.
The growing European Union with its diversity of agricultural conditions
enforces a redistribution of food production and a new structuring of the land-use.
An overriding issue is the conservation and useful distribution of water. The storage
of water of the wet seasons for use during dry intervals got large priority and the
constructions for this purpose range from big dams, drilling projects and long
aqueducts to small private ponds. The impact these new water surfaces have on
regional climate is difficult to estimate. At the one hand these water resources allow
the irrigation oflarge areas in which the land surface properties are changed and on
the other hand the ground water level in adjacent areas is lowered by the
concentration of the water. A study was carried out by the Turkish Department of
Meteorology of the impact of the southeastern Anatolian irrigation project on
regional climate. The project is composed of 22 dams (19 hydroelectric power
plants) with a total irrigation area of 1. 7 10 6 ha which would affect an area of7 4.000
km 2 when completed in 2010. So far no significant signals could be detected in both
long term temperature and precipitation data. The statistics of extreme events on the
other hand shows an increase of high temperatures and an decrease of low
temperature but no effect was detected in the precipitation. In 1992 the low
temperature periods were at an extreme of 33 cases (Halpert et al., 1993). Model
simulations indicate an increase of the precipitable water in the lower levels ofthe
atmosphere COnal, Karaca, and Dalfes, 2000).
Another factor is the competition in the production offield fruits. In many places
cultures are planted to obtain an economic advantage though looking at the totality
of the European production and the import from elsewhere in the world these
products are partly superfluous. They are also quickly changed if the production
becomes unattractive respectively if subventions are cancelled. In this connection it
is interesting to note that in parts of the Ottoman empire, e.g. Palestine, because of
the taxation of trees these by the time vanished completely (Wagner, 2001, p. 230):
"Political ecology" obviously played an important role since ever. In Italy some areas
such as Ie Crete (SE of Siena) which were abandoned are taken under the plough
again to grow grain. In Spain as well as in Italy rocky land is made available for
agriculture again by smashing even large stones with big machines. Urbanization
is growing in coastal areas and land is transformed to generate an environment for
tourism. Fortunately a growing number of "natural parks" are conserved.