Management of coastal dune systems

Abstract

Sand dunes have an important buffer function as they protect assets behind the beach from inundation by the sea and coastal erosion. In many instances this function is overlooked and the dunes are destroyed leading to the loss of the buffer and a resultant increased hazard which becomes a management issue.

The purpose of this study is to examine the relationship between dune morphology and the factors influencing it. In particular concentrating on the concept of preferred dune form in connection with the effects of vegetation and dune confinement.

The results suggest a preferred dune form exists which is asymmetrical in shape. The shape is the same for both the confined and unconfined dunes, but the length of the confined dunes is shorter and the height is lower. This means the confined dunes are not as bulky as the unconfined dunes, thus they have a lesser volume of sand.

These findings have major implications for dune management. Three dune management proposals are examined in the light of these findings. Two of these proposals show how a lack of understanding of these findings can enhance problem situations and mean the project objectives are not fulfilled. The third proposal seems to satisfy the findings in this report.