Stratégies d'adaptation des agriculteurs face à la pénurie d'eau et à l'évolution de l'accès à l'eau : enseignements tirés du bassin versant du Lebna au Cap Bon et de la plaine de Kairouan (Tunisie)

Irrigating farmers in Tunisia are facing a variety of risks, including increasingly frequent water shortages, due to institutional, political and climate changes. To protect themselves from these risks, farmers implement a variety of adaptation strategies that can be classified into three categories: (i) water management adaptations; (ii) changes in farming practices and productions; and (iii) farm-household management options. Understanding the factors driving farmers’ choices is crucial to support them in their strategies to mitigate and cope with water scarcity. Economic literature related to farmers’ vulnerability and adaptation has pointed out the role of various livelihood assets (natural, physical, financial, human and social), as important factors to reduce farmers’ vulnerability. More recently, several studies, based on the Protection Motivation Theory, showed that psychological factors are of crucial importance in the adoption of water conservation practices. Following these works, we address three research questions in this study: (i) How did Tunisian irrigating farmers adapt to various water scarcity events in the recent past? (ii) What are their strategies to adapt to future water shortages? (iii) What are the respective role of assets endowment and psychological factors to explain their past and future adaptation strategies? We conducted a survey with 58 irrigating farmers in four public irrigation schemes in the downstream part of the Lebna catchment, in the Cap Bon region of Tunisia. Irrigation water supplied by the public schemes either originates from the Lebna dam, or from the Medjerda-Cap Bon canal transferring water stored in dams along the Medjerda River valley. An increasing number of farmers complement their water supply with private wells taping shallow groundwater. Faced with drought, which is the main cause of water scarcity in the recent years, the interviewed farmers implement a high diversity of adaptations, often several of them at the same time. Adaptations related to water management (changes in irrigation doses, reallocating water among crops, water storing, seeking alternative sources) are dominant when the drought occurs, while in the medium term adaptations more often concern crop choices and management (fallowing, choice of crops with low water needs, change of varieties, diversification of crops...). Except for the decreasing of non-essential family expenses and decapitalization, adaptations affecting the household as a whole are less frequent. Both in the short and medium term, adaptation strategies vary according to the irrigation scheme, depending on the mix of water sources available to farmers. The results confirm that beyond assets endowment, farmers’ adaptation strategies are influenced by their perception about their capacity to implement each measure and about measure relative effectiveness.