No abstract

Groundwater resources in semi-arid areas and especially in the Mediterranean face a growing demand for irrigated agriculture and, to a lesser extent, for domestic uses. Consequently, groundwater reserves are affected and water-table drops are widely observed. This leads to strong constraints on groundwater access for farmers, while managers worry about the future evolution of the water resources. A common problem for building proper groundwater management plans is the difficulty in assessing individual groundwater withdrawals at regional scale. Predicting future trends of these groundwater withdrawals is even more challenging. The basic question is how to assess the water budget variables and their evolution when they are deeply linked to human activities, themselves driven by countless factors (access to natural resources, public policies, market, etc.). This study provides some possible answers by focusing on the assessment of groundwater withdrawals for irrigated agriculture at three sites in North Africa (Morocco, Tunisia and Algeria). Efforts were made to understand the different features that influence irrigation practices, and an adaptive user-oriented methodology was used to monitor groundwater withdrawals. For each site, different key factors affecting the regional groundwater abstraction and its past evolution were identified by involving farmers' knowledge. Factors such as farmer access to land and groundwater or development of public infrastructures (electrical distribution network) are crucial to decode the results of well inventories and assess the regional groundwater abstraction and its future trend. This leads one to look with caution at the number of wells cited in the literature, which could be oversimplified. (Résumé d'auteur

Since the 1980s, the Biskra region in Algeria's Sahara has undergone rapid agricultural change leading to territorial transformation. Horticultural production under greenhouses, associated with a rapid expansion of date palm plantations, has led to a tangible agricultural boom that is constantly pushing the boundaries of agricultural production and constitutes a true pioneering fringe. To understand the pioneering logics at work, we propose to study the pioneer fringe through three fronts, namely land, water and infrastructure. First, we analyse each front separately in order to understand its logic. In a second step, through three illustrations, we show how these fronts interpenetrate, accelerate one another or, on the contrary, constrain the pioneer fringe. The analysis of the advance of the pioneering fringe has shown that it results from the interweaving of the three main fronts and each of these combines both the actions of the state and private initiative. © 2018 John Wiley & Sons, Ltd.