Developing an Integrated Flood Management Plan under climate change for Grand River North West River basin, Mauritius

Abstract

Abstract. In this article, the catchment of Grand River North West (GRNW) in Mauritius was selected as a case study to develop an Integrated Flood Management Plan to address the flood risks that Mauritius is and will be facing due to climate change. The study contains three main components: (i) a climatology analysis for the past (2003–2018) and future climate (2025–2040) to assess the trends in floods under climate change, (ii) the development of a hydrological model to study the hydrological responses of the basin for extreme flooding events, and (iii) a GIS-based flood risk model to develop a risk map. The results show that extreme rainfall events exceeding 50 mm d−1 have a high likelihood of increasing. A flood vulnerability map for the basin was developed based on nine indicators to aid decision making at the village council area (VCA) level and guide financial investments flood mitigation measures. The study established a novel end-to-end approach to develop an Integrated Flood Management Plan based on a case study for a river basin in Mauritius.