Assessment of Water Quality and Quantity Changes in Ras Jbel and Guenniche Aquifers (North-Eastern Tunisia) due to Artificial Recharge.

Jamila Hammami, Boutheina Farhat, Abdallah Ben Mammou

Friday 3 july 2015

12:57 - 13:00h at Europe 1 (level 0)

Themes: (T) Hydro-environment, (ST) Rehabilitation of water systems, Poster pitches

Parallel session: Poster pitches: 15G. Environment - Renewable & Wetland

In the aquifer of Metline-Ras Jbel-Raf Raf and the aquifer of Guenniche (North Eastern Tunisia), groundwater plays an important role for social and economical development. Water in both aquifers is the sole drinking and irrigation source for local residents. However, with the rapid increase in population, the extraction of groundwater is reaching its maximum capacity. This intensive exploitation has considerably lowered the water table in and around the water catchments. Groundwater salinization and degradation is usually observed through sampling of pumping wells. One supply augmentation practice, that is already being applied in north-eastern Tunisia, is artificial groundwater recharge using freshwater from SECADENORD. The purpose was to artificially replenish the overexploited aquifers, and thereby partially restore the water table levels while maintaining production capacity. The impact of artificial recharge on the quality and the quantity of both aquifers water then becomes a more pressing concern. Field measurements of piezometric levels and physicochemical parameters, along with hydrochemistry analysis of groundwater were carried out in both Ras Jbel and Guenniche aquifers during four campaigns before and after artificial recharge. Results of field and laboratory analyses showed variations of chemical compositions across the study areas. A drop in piezometric level is be remedied by artificial recharge of groundwater. Artificial recharge decreases also the high degrees of salinities in both aquifers. Keys words: Ras Jbel aquifer, Guenniche aquifer, overexploitation, artificial recharge, water quality, water quantity.