Approach
Many U.S. recreation destinations that are the most vulnerable to near-term effects of climate change are located along shorelines. Global sea levels have risen by about 8 inches since the advent of reliable record-keeping in 1880, and 2017 marked the sixth consecutive year that the global mean sea level was the highest on record. Sea level rise can also amplify erosional effects of waves and storm surge, which may cause higher rates of infrastructure damage. Shoreline stabilization techniques are organized along a continuum between hard armoring and soft armoring, with hybrid techniques that include elements of both. Hard armoring techniques, such as such as retaining walls, seawalls, bulkheads, and revetments, can stabilize a shoreline quickly, but can also cause additional problems in the long term due to altered sediment transport, shoreline migration, impacts to wildlife and stabilizing vegetation, and scouring at the toe of the structure. Soft armoring, or living shorelines, utilize natural vegetation and other elements to increase resistance to flooding or storm surges, while preserving natural sedimentation processes, habitat characteristics, and associated ecosystem services.
Tactics
- Install hard armoring, such as retaining walls, seawalls, bulkheads, and revetments, e.g. rip-rap. Ensure that these structures allow rainwater to drain so that they do not create pools of water behind them.
- Practice soft armoring. Plant or retain native vegetation, such as cordgrass, seagrass, mangroves, willows, etc., in order to hold coastal or riparian soil in place and provide a buffer to uplands.
- Incorporate hybrid techniques into a living shoreline, such as installing geotextile tubes at the edge of plantings or vegetated rock sills at the toe of a slope.
- Create a breakwater offshore to reduce wave energy and/or erosion reaching the shoreline. This can be composed of rock, concrete, or bagged oyster shell coupled with oyster restoration mats in order to produce a living breakwater.
- Practice beach nourishment by dredging or otherwise transporting sand onto beaches in order to increase the buffer between waves and vulnerable infrastructure. This tactic is most effective when combined with dune construction or berms [1].
Strategy
Strategy Text
The impacts of climate change will stress the existing recreational infrastructure that is located in vulnerable locations, such as along coastlines and shorelines with fluctuating water levels, within floodplains, in drought-prone areas, or in areas that are projected to experience dramatic increases in precipitation. There are a number of instances in which recreation managers might wish to retain infrastructure in place despite site-specific vulnerabilities. Examples include cultural, historic, or interpretive sites that are dependent on their location to provide contextual integrity, or other sites whose proximity to water or snow is essential to their recreational character. Additional considerations could include the sheer force of prior investment in a site, or the political or social infeasibility of taking alternate actions. This strategy actively works to maintain key infrastructure in place by increasing its resistance to current and future environmental conditions. Application of this strategy does not remove the risks that affect vulnerable infrastructure, and in some instances, an increasing risk of failure may be experienced over time, which could necessitate a reevaluation of adaptation options over the long term.
O’Toole, D.; Brandt, L.A.; Janowiak, M.K.; Schmitt, K.M.; Shannon, P.D.; Leopold, P.R.; Handler, S.D.; Ontl, T.A.; Swanston, C.W. Climate Change Adaptation Strategies and Approaches for Outdoor Recreation. Sustainability 2019, 11, 7030.