Erosion studies on Mauritius: overview and research opportunities

Mauritius is a Small Island Developing State (SIDS) with a high population density and increasing agricultural, urban and infrastructural demands, superimposed over limited physical resources. Soil and coastal erosion are recognized as an important environmental challenge facing the island. Here we review the studies on soil erosion over the past two decades and more recent advances in understanding the coastal erosion dynamics. Soil erosion studies have focussed on catchment erosion rates using recognized modelling techniques that have also permitted the mapping of erosion risk for the island. Rainfall assessments using six-minute rainfall data have detailed erosivity conditions for a section of the island but these findings still need to be incorporated into island-scale models. On Round Island, an off-shore Nature Reserve, erosion forms and rates have been measured in support of conservation and restoration programmes. Along the coastline, erosion had been long-recognized as a concern, particularly where development encroaches on the shoreline, and ongoing monitoring is assisting in understanding coastal sediment changes. Further research opportunities are noted and these include a coastal vulnerability assessment and modelling catchment sediment source-sink attributes where there is an impact on lagoon and coral structures. Climate-change scenarios, notably the effects on rainfall erosivity and sea level, are still to be incorporated in studies.