The morphologic impacts of cyclone Kalunde on the beaches of Rodrigues island (Western Indian Ocean).

The cyclone Kalunde has had three main morphologic effects on the sandy coasts of Rodrigues: the lowering of beaches, comprised between 0,20 and 1 in, dune receding which reached 7 m in some places and the breaking of barrier beaches which were overflooded by rivers. The importance of these manifestations varied significantly from one place to another along the eastern coast of Rodrigues. Beach profiles which were established three months after this event revealed the unequal resilience of beaches. Whereas some of them had entirely recovered from the erosion due to the cyclone, others had not. The author of this paper analyzes the role of coral reefs and dunes in the recent evolution of beaches. She emphasizes on the two different functions of coral reefs which should act as breakwaters and as a source of sediment for beaches. Where they don't play efficiently these roles as in Rodrigues, they contribute to beach erosion. Coral reefs limit the transfer of sediments from the submerged sandy plain and the reef flat to the beach itself.