Early-Warning System for storm surge and tide in Mauritius

The Republic of Mauritius is the first Small Island Developing State (SIDS) in the Indian Ocean with its own tide and storm surge Early-Warning System for improving preparedness and resilience to events like cyclones. Deltares developed the storm surge model together with the Ministry of Environment, Sustainable Development, Disaster and Beach Management. It predicts where and when a storm surge is to be expected.

mauritius storm

The Mauritius Early-Warning System

During this project, the team developed and implement operationally a fully-automated Early-Warning System for incoming storm surge and tide for the Republic of Mauritius, such that coastal communities in Mauritius, Rodrigues and Agalega Islands are able to evacuate timely and safely in case of predicted extreme water levels. The project comprised several phases (inception, assessment, system design, implementation and capacity-building) during which Deltares’ expertise and software were adjusted to the local desires and needs. Active participation in several workshops in Port Louis, Mauritius by Deltares specialists to meet and discuss with important stakeholders and system end-users was instrumental.

Free software

The Mauritius Early-Warning System for storm surge and tide was implemented using software from Deltares’ Open-Source and free software community.  A set of five 2DH Delft3D hydrodynamic models are run every six-hours with a forecast horizon of three days, simulating coastal water levels along the coast of the three main islands. Two regional models of horizontal resolution 5km force the three detailed models of 500m resolution; all models are forced at the surface by the 0.25° NOAA/GFS meteorological forecasts. In addition our Wind-Enhancement Scheme (WES) is used to blend detailed cyclone track bulletin’s info with the largerscale numerical Weather Predictions. Further, data is retrieved near real-time from available Automatic Weather Stations. All these workflows are managed by the operational platform software, Delft-FEWS.

Project leader Joao de Lima Rego: ‘This nation-wide forecasting system produces three-day forecasts every six hours based on the most recent weather forecasts and the tropical cyclone bulletins issued by the Joint Typhoon Warning Center. The system has been installed at the Mauritius Meteorological Service in Vacoas, Mauritius, and it was a pleasure to work together with and train the staff operating the early warning system.’