Canadian Coastal Conference 2003 Conférence canadienne sur le littoral 2003 Variations in a beach/foredune system 1 J. Ollerhead SEASONAL VARIATIONS IN A BEACH AND FOREDUNE SYSTEM, GREENWICH DUNES, PRINCE EDWARD ISLAND NATIONAL PARK Jeff Ollerhead 1 , Robin Davidson-Arnott 2 , Paul Johnston 2 , Ian Walker 3 & Patrick Hesp 4 1 Department of Geography, Mount Allison University, Sackville, NB, Canada E4L 1A7 2 Department of Geography, University of Guelph, Guelph, ON, Canada N1G 2W1 3 Department of Geography, University of Victoria, Victoria, BC, Canada V8W 3P5 4 Department of Geography, Louisiana State University, Baton Rouge, LA, USA 70803 ABSTRACT Nine profiles with three to eight 1 m 2 bedframe stations per profile were established across the beach and foredune at Greenwich Dunes in Prince Edward Island National Park in 2002. Surface elevation, along with vegetation type, cover and height are measured within each quadrat. Measurements will be carried out 3-4 times a year over the period 2002-2005. A meteorological station was also installed in 2002. Data collected will be used to evaluate the importance of variables thought to control short-term beach/dune dynamics including wind regime, variations in beach width, and changes in vegetation. Ultimately, the data will be used to provide predictions of beach dune dynamics over periods of years to decades. Foredune height ranges from 3.8-11.5 m and, with the exception of one location, stoss slopes are all very steep with angles ranging from 29-45º, reflecting the frequency of dune toe scarping by wave action. Vegetation height in June 2002 ranged from 0.25-0.50 m and growth over the summer averaged 0.26 m. Vegetation cover varied greatly with a few quadrats at < 5%, a few at >70 %, and the majority in the range 20-50%. Vegetation cover changed little over the summer and fall of 2002. At 7 of 9 profiles, <20 % of total deposition for the summer-fall period accumulated during summer. Deposition occurred primarily during the fall and primarily on the stoss slope and foredune crest, with much less deposition on the lee slope. Nevertheless, the data show that even though the stoss slope is scarped and very steep at many locations, sediment is being transported to the lee slope and thus dune migration is occurring. INTRODUCTION It is well established that the north coast of Prince Edward Island (PEI) is sensitive to sea level rise and that it is likely to experience ongoing geomorphic change in coming decades as relative sea level continues to rise and as our global climate changes (Shaw et al., 1998). This coast is comprised primarily of till bluffs and sandy barrier systems, environments that change relatively rapidly in response to changes in related geomorphic controls. INDEX