Stephens, S.A.; Bell, R.G.: Lawrence, J. (2017). Applying principles of uncertainty within coastal hazard assessments to better support coastal adaptation. Journal of Marine Science and Engineering 5(3): 40; doi:10.3390/jmse5030040
Abstract: Coastal hazards result from erosion of the shore, or flooding of low-elevation land when
storm surges combine with high tides and/or large waves. Future sea-level rise will greatly increase
the frequency and depth of coastal flooding and will exacerbate erosion and raise groundwater
levels, forcing vulnerable communities to adapt. Communities, local councils and infrastructure
operators will need to decide when and how to adapt. The process of decision making using
adaptive pathways approaches, is now being applied internationally to plan for adaptation over
time by anticipating tipping points in the future when planning objectives are no longer being met.
This process requires risk and uncertainty considerations to be transparent in the scenarios used in
adaptive planning. We outline a framework for uncertainty identification and management within
coastal hazard assessments. The framework provides a logical flow from the land use situation,
to the related level of uncertainty as determined by the situation, to which hazard scenarios to model,
to the complexity level of hazard modeling required, and to the possible decision type. Traditionally,
coastal flood hazard maps show inundated areas only. We present enhanced maps of flooding
depth and frequency which clearly show the degree of hazard exposure, where that exposure occurs,
and how the exposure changes with sea-level rise, to better inform adaptive planning processes.
The new uncertainty framework and mapping techniques can better inform identification of trigger
points for adaptation pathways planning and their expected time range, compared to traditional
coastal flooding hazard assessments.