développement actuel et futur de la Tunisie.
du pays
reçoit les plus grandes quantités de précipitations (plus de
400 mm/an), englobe les bassins du Nord-Est (Cap-Bon,
Miliane et Ichkeul) et ceux du Nord-Ouest (Medjerda et
extrême Nord). Quant au Centre (entre 400 mm et 200
mm/an) et au Sud (inférieur à 200 mm, souvent à100 mm),
ils sont caractérisés par l'aridité et l'endoréisme. La figure 1 et
le tableau 1 montrent la répartition spatiale du réseau hydro-
graphique et des précipitations, ainsi que les trois grandes
régions hydrologiques du pays. Il ressort de ce tableau que le
Nord fournit 82 % des ressources, le centre 12 %, et le sud 6
%, ce dernier représentant 62 % de la superficie du pays.
des nappes du sud (tableau 2), dont les plus importantes
sont les nappes profondes fossiles du Continental interca-
laire et du Continental Terminal. Le caractère fossile des
nappes du Sud pose le problème de la durabilité de leur
plus considérée comme une région de mise en valeur par
future.
to be found and which receives the heaviest rainfall (over
400 mm/yr), comprises the catchment basins of the north-
east (Cap-Bon, Miliane and Ichkeul) and those of the north-
west (Medjerda and the far north). Aridity and endoreism
typify the centre (between 200 and 400 mm/yr) and the
south (less than 200 mm/yr, and often under 100 mm/yr).
Figure 1 and Table 1 show the geographical distribution of
the hydrographic network and precipitation, and the three
major hydrological regions in the country.
the country's water resources, the centre 12% and the south
6%, although the latter constitutes 62% of the area of
Tunisia.
found in the deep aquifers of the south (Table 2), the largest
of which are the deep fossil aquifers of the Continental
of these groundwater reservoirs in the south poses the prob-
gramme "Planning and Management of Water Resources in the Sahel of Sousse and the Region of Sfax",
within the framework of Franco-Tunisian cooperation.
(physical milieu and socio-economic context), and teledetection (SPOT images), in order to construct a
Geographical Information System (GIS) that will be used in integrated regional development and in the
management of natural risks. The project is being piloted in two catchment basins in central and south-
ern Tunisia, in which intensive exploitation of water and soil resources has led to serious imbalances,
apparent in soil erosion and in the falling levels and the salinization of groundwater. The GIS will serve
as a decision-making tool in the quest for sustainable development.