Using AHP-PROMOTHEE for Selection of Best Low-Impact Development Designs for Urban Flood Mitigation

This work first studies the effects of several Low Impact development methods on urban flood control. The Analytic Hierarchy Process-Preference Ranking Organization Method for Enrichment Evaluation (AHP-PROMETHEE) combination method is then used to select the best design. A drainage system in Golestan town of Semnan under a 5-year return period is investigated as the case study. The LID methods are selected based on the region's conditions and facilities. Then Rain Barrel (RB), Permeable Pavement (PP), and Infiltration Trench (IT) were considered as LID methods. The RB, PP, IT, IT-PP, IT-RB, PP-RB, and IT-PP-RB are considered the best LID usage scenarios. Four analytical ranking criteria, implementation cost, hydraulic performance, environmental impact during implementation, and ease of implementation, are chosen for the ranking procedure. Also, the weight of these criteria was obtained using Analytic Hierarchy Process (AHP). Finally, after determining the weight criteria, the LID designs are ranked using the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) method. The results of hydraulic studies demonstrate the effectiveness of the PP-RB scenario with an average reduction of 90% of peak discharge and an average reduction of 80% of total flood volume. It is also observed that the weakest performance is related to the IT scenario, with an average decrease of 60% of peak flow and 47% of total flow volume. AHP-PROMETHEE analysis showed that the simultaneous use of RB and IT with a coverage percentage of 5% and a cost of $ 57,710 reduced the total volume by 51.54% and the peak discharge by 48.8% compared to the results of the current system. According to AHP-PROMETHEE, IT-RB-5 is the best project proposed among the 70 projects studied. This study showed that the AHP-PROMETHEE method is a practical method for choosing from several LID schemes for flood control.