Coastal Dune Blowouts?Dynamics and Management Implications

by Paul A. Gares, Colgate Univ, Hamilton, United States,
Karl F. Nordstrom, Colgate Univ, Hamilton, United States,



Document Type: Proceeding Paper

Part of: Coastal Zone '91

Abstract:

New approaches to coastal dune management have been advocated recently, including dune grading and dune destabilization. A management concern in the case of destabilization involves the role of blowouts which are common features in coastal dune fields. The purpose of this paper is to demonstrate the degree to which blowouts affect the sediment budget of a dune system in Island Beach State Park, New Jersey. A field site in the northern natural area of the Park has been monitored for the last decade. Until 1978, management practice in this zone was to stabilize the dune system using sand fences and vegetation planting. Large topographic changes have taken place in the dune system at this site since 1981, primarily involving the development of a large blowout through the foredune. This study examines the volumetric change in the dune system from 1981 to 1989. The role of the blowout is determined by comparing its sediment budget to that of an adjacent undissected foredune. This study reveals the magnitude of the topographic change due solely to eolian action in a foredune system where no attempt is made to close breaches or repair blowouts. The blowout has a balanced sediment budget, and it affects topographic change a limited distance inland from the beach. The implications of these findings to managers are that the blowouts should not be viewed as predominantly erosional features requiring repair, and that they they are integral to the dynamic system that the Park managers are trying to preserve because they perform a valuable function by facilitating sediment transport into the dune system which can reinvigorate existing plant species and increase species diversity.

Subject Headings: Dunes | Coastal management | Sediment transport | Topography | Sediment | Parks | Erosion | New Jersey | United States

Services: Buy this book/Buy this article

 

Return to search