Estimating and mapping natural hazards and risk reduction provided by coastal ecosystems

We present two case studies in which coastal vulnerability modeling was used to quantify the role those coastal ecosystems play in reducing risk to coastal communities now and with future sea-level rise. These analyses were used to inform post-disaster reconstruction and coastal resilience building efforts as well as climate change adaptation strategies. Our goal is to quantify the role that coastal habitat plays in reducing risk to people and shoreline under current conditions and with future sea level rise (SLR). With SLR, we find that the extent of shoreline most exposed to coastal hazards would more than double, and the total population would nearly triple in The Bahamas. Similarly, the population living along high-risk shorelines increases by over 10x if habitat is lost and sea level rise is accounted for in the Mesoamerican Reef. The model is designed to be very accessible; it produces robust results using relatively coarse, often globally available data inputs, the methodology is transparent and the model outputs are easy to interpret, and running the mode l requires basic GIS skills but no other specialized training.