Despite recent advances in both coastal science and coastal management scale issues and modelling uncertainties often prove to be major constraints on communication between the two communities. Models of dune evolution provide some guidelines for best management practices but they do not analyze process dynamics, making them insufficient for predictive purposes. Ironically, despite numerous studies, researchers are still unable to provide a straightforward answer when managers asks how much sediment will be delivered to a particular coastal dune over a period of time of weeks, months, or years. The availability of new field and computer techniques has now made it possible to return to this issue, and to attempt to develop a quantitative understanding of the physical processes leading to sediment input to coastal dunes at a temporal scale that is meaningful to management (i.e., the meso-scale). Morphodynamic classifications predict general relationships between dune form and beach type and tidal range, but not detailed predictions of the rate of sediment delivery. Recent studies on a micro-tidal coast show that aeolian activity is significantly reduced during strong onshore wind events, leaving the largest percentage of sediment input to coastal dunes to medium magnitude/frequency wind events. This paper presents preliminary data from a long-term monitoring program designed to understand the nature of aeolian transport events on a macro-tidal beach-dune system. The monitoring station is located at Sefton Dunes, the largest coastal dune field in England, and includes an array of digital cameras and sensors that measure factors controlling sediment input to the dunes, such as wind and transport processes, surface moisture content, beach width and fetch distances. The working hypothesis is that the probability of strong onshore winds resulting in aeolian activity will still be reduced compared to the theoretical value and hence calculations of sediment input to coastal dunes based on wind speed and direction only will overpredict dune sediment budgets in macro-tidal coasts. The scope of the monitoring station will be expanded to include all aspects of interactions between the intertidal and beach zones and the dune system and the intention is to maintain the monitoring program over the next decade.
|Published - 2012
|18th Windy Day - University of Leicester, United Kingdom
Duration: 17 Oct 2012 → …
|18th Windy Day
|17/10/12 → …