CHANGES IN THE RESOURCES MANAGEMENT AND THEIR ENVIRONMENTAL CONSEQUENCES IN A SAHARAN ARID ENVIRONMENT THE CASE OF THE JEFFARA PLAIN, THE NEFZAOUA OASES AND THE SEHIB AREA IN SOUTHERN TUNISIA

摘要

Since the earliest antiquity, natural resources in southern Tunisia have been used within the scope of a collective organization and of a balanced and sustainable management. However, from the beginning of the 20th century, the local populations way of life underwent changes that entailed the occurrence and development of a new way in using resources (especially regarding water and land), based on individual initiative and often regardless of the social regulations in force.rnThe present study highlights from one hand environmental changes from case studies regarding the Jeffara (south-east), and the Nefzaoua (south-west), Tunisian regions that have been suffering unprecedented degradation of natural resources, due to various pressures.rnFrom the other hand, a third case study, regarding the Sehib area (southern low plains) is an example of an environment that has kept its balance, thanks to the population well thought-out and sustainable management of its natural resources. This work used multi-source data, like aerial photographs, satellite images from different dates, auxiliary data and field work. We have studied the management of natural resources in relation to the potential of the environment on the one hand, and to the needs of the concerned populations on the other hand, through a monitoring of the spatial dynamics of land use and land cover in southern Tunisia.rnThe aim is to define the areas affected by important dynamics, to draw the attention to the need of a strategic, integrated and joint approach of the natural resources management. Such management should particularly rely on the protection and restoration of local knowledge, as well as the correction of the mistaken assessments of the "official science".