Assessing Sea Level Rise Vulnerability and Costs in a Data Limited Environment

Abstract

“Resiliency” for communities at risk from sea level rise and its effects means preserving as much property and associated economic activity as possible without disrupting current activity or expending funds on projects that provide limited long-term utility or social value. Of interest is how the coincidence of these events impacts the need for storm water improvements and the financial obligations they will entail. This research project focused on the impacts of a non-coastal, groundwater influenced southeast Florida community and the long-term funding they will need to reduce flooding in the community using GIS. This research involved defining surface elevations and groundwater levels, assessing the impacts of sea level rise on groundwater, assessing impacts to storm water from rainfall, identifying likely improvements, and assessing the scale for improvements. The analysis used three extreme rainstorm events under the 0-, 1-, 2-, and 3-foot sea level rise scenarios to determine the magnitude of the cost of the improvements. For a 35-square mile community, our research estimated that the cost could exceed $300 million. For a community not directly adjacent to the coast, the magnitude of these costs should be of interest to similarly placed communities.

Best Practices for Elevation-Based Assessments of Sea-Level Rise and Coastal Flooding Exposure

“…These areas have been referred to as locations with "groundwater inundation" (Rotzoll and Fletcher, 2012), although the inundation may not always be due solely to raised coastal groundwater tables, but also king tides, run-up of high waves, or some combination of these factors. The importance of distinct mapping of low-lying areas susceptible to flooding has been recognized in many studies (Cooper et al, 2012(Cooper et al, , 2015Bloetscher and Romah, 2015;Bloetscher et al, 2017;Hummel et al, 2018;Knott et al, 2018). These delineations of low-lying lands should carry the same expression of confidence level of mapping or probability of inundation resulting from proper consideration of vertical uncertainty.…”

Inundation Exposure Assessment for Majuro Atoll, Republic of the Marshall Islands Using A High-Accuracy Digital Elevation Model

“…In some cases, these areas have been referred to as areas with "groundwater inundation" [41,42], although the inundation may be due to not only raised groundwater levels but also king tides, run-up of high waves, runoff from precipitation, or some combination of these factors. The importance of mapping these low-lying areas has been recognized in numerous studies [8,22,[43][44][45][46][47][48][49]. The simplest, and most often employed, method of mapping projected inundation onto the land surface raises the water level on a coastal DEM by delineating all areas that fall below a specified elevation (at the height of the raised water level).…”