Some considerations on coastal processes relevant to sea level rise

Abstract

The effects of potential sea level rise on the shoreline and shore environmenthave been briefly examined by considering the interactions between sea level rise andrelevant coastal processes. These interactions have been reviewed beginning with adiscussion of the need to reanalyze previous estimates of eustatic sea level rise andcompaction effects in water level measurement. This is followed by considerations onsea level effects on coastal and estuarine tidal ranges, storm surge and water levelresponse, and interaction with natural and constructed shoreline features. Thedesirability to reevaluate the well known Bruun Rule for estimating shoreline recessionhas been noted. The mechanics of ground and surface water intrusion with reference tosea level rise are then reviewed. This is followed by sedimentary processes in theestuaries including wetland response. Finally comments are included on some probableeffects of sea level rise on coastal ecosystems.These interactions are complex and lead to shoreline evolution (under a sea levelrise) which is highly site-specific. Models which determine shoreline change on thebasis of inundation of terrestrial topography without considering relevant coastalprocesses are likely to lead to erroneous shoreline scenarios, particularly where theshoreline is composed of erodible sedimentary material.With some exceptions, present day knowledge of shoreline response to hydrodynamicforcing is inadequate for long-term quantitative predictions. A series of interrelatedbasic and applied research issues must be addressed in the coming decades todetermine shoreline response to sea level change with an acceptable degree ofconfidence. (PDF contains 189 pages.)