Evolution of salty surfaces on the Kerkennah archipelago between 1963 and 2010

The modification of the regional climate since the 70’s and the evolution of the standard of living on the Kerkennah archipelago (Gabes gulf, Tunisia) led on the perturbation of the archipelago environment and of the farming practices. The archipelago has a low topography that favors the sabkha development (low and salty lands). They overlay today 45% of the entire surface. In order to quantify the sabkha extension, a GIS has been made to compare a satellite image from 2010 and aerials photographs from 1963. It appears that the extension reach 465 ha (or +18 %) between both dates. A questionnaire has been proposed to the population (150 peoples) to evaluate the perception of salinization. It seems that the population understands the ongoing changes and the causes that are due to both climate evolution and anthropic activities in mutation.