Hierarchical Structuring for the Olive Trees Irrigation Problem in Tunisia

The problem of choosing the best type of water for the irrigation of olive trees is one of the decisions that have a crucial impact on the water resource management. To solve this problem, we propose a multi-expert approach, implying several quantitative and qualitative criteria and combining the AHP method and Shannon’s entropy probability method. First, we use the AHP method to calculate all criteria weights for the various hierarchical levels as well as weights of the alternatives. Using the results obtained, we rank the types of water according to four experts. However, the data supplied by the experts are contradictory. We therefore combine these results according to the experts’ importance. We used Shannon’s entropy to determine the importance degree of each expert, to aggregate the results. The proposed approach showed that using well water was selected as the best for irrigation. Reuse of treated wastewater was classified as second, followed by desalinated brackish water and, next, by desalinated seawater