INTEGRATED GIS-MCDA FRAMEWORK FOR OPTIMAL FLOOD RETENTION POND SITE SELECTION: A CASE STUDY IN REMBAU, MALAYSIA

Abstract

Flooding poses severe risks to human lives, infrastructure, and economies globally. Effective flood management depends on strategically locating mitigation measures like flood retention ponds, which regulate stormwater and reduce downstream flooding. Traditional site selection methods often suffer from limited data use and subjective judgment, weakening mitigation outcomes. This study applies an integrated Geographic Information System (GIS) and Multi-Criteria Decision Analysis (MCDA) framework using the Analytic Hierarchy Process (AHP) to prioritise flood retention pond sites in Rembau, Malaysia. Utilising high-resolution spatial datasets Digital Elevation Models, Land Use and Land Cover maps, hydrological and infrastructure data, and socio-economic factors combined with expert and stakeholder input, the model produces suitability maps that balance economic, environmental, and social considerations. Results identify optimal sites along natural drainage networks and moderate slopes, enhancing stormwater capture, minimising construction challenges, and reducing social disruption. Scenario analysis reveals trade-offs: economic scenarios favour cost-effective agricultural lands but risk ecological impacts; environmental-social scenarios prioritise conservation and community welfare but increase costs; combined scenarios achieve a balanced, sustainable approach. Overall, this study demonstrates that stakeholder engagement strengthens the model's suitability and promotes flood mitigation planning that is data-driven and context-specific. The proposed GIS-MCDA framework provides a reusable tool for developing sustainable and resilient flood management strategies.