Hazard sensitivity in Newfoundland coastal communities : impacts and adaptations to climate change, a case study of Conception Bay South and Holyrood, Newfoundland

Abstract

Impacts and adaptations to climate change on the coastal zone of the communities of Conception Bay South and Holyrood, Newfoundland were investigated. Based on the concept of geoindicators and unique shore-zone morphology, a coastal hazard sensitivity assessment was conducted to assess the present sensitivity of the Conception Bay South-Holyrood coastline to the impacts of flooding and erosion. As the most immediate effects of climate change will be felt along the coastline, the implications of future climate change and variability in Atlantic Canada on the Conception Bay South-Holyrood coastline were then considered. -- Results of the hazard sensitivity assessment indicate that overall, the Conception Bay South-Holyrood coastline has a low to moderate sensitivity to coastal flooding and erosion. However, subsequent analysis reveals that these results mask important differences in sensitivity based on differences in morphology. Results of the flood hazard sensitivity assessment indicate that the most sensitive segments of coastline surround the numerous lagoons located in Conception Bay South. The majority of the "exposed straight" coastline has a low sensitivity to flooding. In the foreshore erosion hazard sensitivity assessment, sections of coastline classified as barrier beach are highly to extremely sensitive to foreshore erosion processes, while segments classified as fringing beach or bedrock dominated receive low to moderate sensitivity ratings. Results of the backshore erosion hazard sensitivity assessment indicate that the majority of the Conception Bay South-Holyrood coastline has a low sensitivity to backshore erosion, a reflection of the fact that a third of the coastline is composed of highly resistant, igneous bedrock. Sections of backshore classified as unlithified are highly to extremely sensitive to erosion and there are a number of segments actively eroding. -- With portions of the Conception Bay South-Holyrood coastline currently sensitive to coastal flooding and erosion and anticipated changes in climatic conditions and accelerated rates of sea-level rise potentially increasing the risk, there are important implications for town management and planning decision-making processes that are capable of supporting sustainable community practices. A number of specific adaptation options, including hazard identification and monitoring; managed retreat or avoidance; accommodation; protection; coastal management and public education, have been recommended to enable current protection and in preparation of accelerated sea-level rise and climate variability in southern Conception Bay.