Assessing environmental impacts of groundwater irrigation using the life cycle assessment method: application to a Tunisian arid region
Résumé
Groundwater irrigation is an opportunity to improve yield, but it also brings about a variety of environmental impacts that go beyond the most noticeable impact of water depletion. In this paper, a multi‐criteria environmental impact assessment based on life cycle analysis (LCA) is conducted at the regional level on the Kairouan Plain (Tunisia) where groundwater withdrawals for irrigation purposes are constantly increasing. At this regional level, we have addressed impacts of both groundwater pumping and cropping practices. The diversity of farming and cropping systems was also accounted for.
Results highlight that the main processes contributing to the impacts on resources—when overlooking impacts on water depletion—are: energy used for groundwater pumping (23%), fertilization (30%), i.e. road transportation of manure (21%), ammonium nitrate manufacturing (9%), and also the manufacturing of irrigation pipes (13%). However, the specific impacts of freshwater depletion on natural resources are by far the most severe when accounted for in the method. Indeed, it is essential that these impacts on freshwater depletion be fully accounted for in this water‐scarce context, especially given the increasing water scarcity predicted by climatic models.