Adaptation Strategies
Coastal zones are some of the most ecologically sensitive and diverse habitats in the world. Currently, these areas are experiencing the detrimental effects of sea-level rise (SLR) and the consequences of conventional flood protection methods. The Living Breakwater Project understands adaptation as both physical interventions and policy planning tools that reduce risks associated with sea-level rise. Based on the British Columbia Sea Level Rise Primer, this research groups adaptation strategies in four (4) different categories: protect, accommodate, retreat, and avoid.
Protect
Protect is defined as a reactive strategy in response to sea-level rise and storm surges. These strategies are usually more conventional structural interventions, e.g., dikes, seawalls, breakwaters, and groynes. Such structures have proven to be effective as a short-term solution. However, over time they are likely to become less effective and will require maintenance and reinforcement due to storm damage. Additionally, hard structures, e.g., dikes and seawalls create negative effects and feedback on ecosystem morphology and dynamics resulting in ecological communities due to habitat modification. Alternatively, strategies such as constructed coastal wetlands, dune systems, and barrier islands are more cost-effective in the long term and can be more beneficial because they provide coastal recreation and ecosystem services.
Accommodate
Accommodate refers to strategies that focus on adapting in place, i.e., using coastal adaptation measures that allow for the occupation of coastal areas even in the face of impending risks, e.g., during the event of a storm. Strategies to accommodate might be more useful in the short term and can be implemented successfully based on judicious risk assessment that identifies safe adaptation thresholds. Common accommodation strategies may involve dry or wet floodproofing, including amphibious buildings, secondary dikes, and crop alterations. floodproofing requires the identification of a set of common criteria for the implementation of flood insurance programs. Using these programs flood insurance is guaranteed for communities that regulate floodplain development.
Retreat
Retreat refers to strategies that limit development in areas that are affected by sea-level rise. These strategies relate to policy planning tools that are meant to relocate private or public assets from areas with high risk to areas with no risk or lesser risk. Retreat strategies may also focus on the abandonment of at-risk assets. Areas that are retreated from will most likely become intertidal or natural buffer zones to accommodate future sea-level rise.
Avoid
Avoid refers to the actions that ensure no new development occurs in areas that are identified as potential flood zones.23 Such areas can be designated as no-build zones. Development control within these zones can be implemented at the lowest local level of municipal planning. Avoid strategies can be implemented through measures such as land acquisitions using purchase or expropriation. Such strategies will allow municipalities to designate expropriated lands as flood zones and hence avoid future development on these lands.
Adaptation Considerations
Many urban delta regions have high variability in flood exposure, coastal ecosystem function, soil conditions, urban settlement and development patterns, and multilevel governance arrangements regarding coastal management. Therefore, adaptation solutions for coastal flooding ought to be developed taking into considerations a wide range of social and environmental conditions. These conditions when considered collectively present themes that may require different approaches to adaptation. For example, a nature-based solution (NBS) approach utilizing wetlands can be effective as wave attenuation during storm surges in order to protect people and coastal assets from erosion and storms. However, in areas where wetlands may not be viable, the most appropriate solution might be retreating from the shoreline or implementing other forms of hard defense, e.g., dikes or a mixture of grey and green coastal infrastructure solutions. In other areas, sediment fences may be used to reduce erosion and simulate sedimentation that can serve as precursor to the rehabilitation of wetlands or mangrove forests. Ultimately, decisions regarding the most appropriate adaptation solutions are contingent on stringent approaches to risk assessment and the appropriate application the risk assessment results towards strategies that contribute to reducing risk but also producing options for enhancing adaptation.
Spatial Integration
Although conventional flood protection strategies have proven to be effective, they do not address the long-term effects of SLR and at times they may harm coastal ecosystems and livelihoods rather than protect them. In most cases, SLR adaptation strategies involve the construction of physical structures and can have an impact on the cultural significance of a community. Therefore, it is important to consider how a proposed adaptation strategy will potentially affect community livelihoods and biodiversity in existing ecological systems.
Adaptation strategies for SLR should fundamentally include consider relationships to existing land uses and ecological functions. These concerns should include topography, geomorphology, available space, land value, risk, safety, ecological value, ecosystem services, and cultural significance, to name just a few. High land use density can significantly limit the applicability of adaptation measures in coastal areas where it is difficult to allocate space for the implementation of adaptation strategies. Furthermore, land value can also impact the acquisition of available space as implementing large-scale flood protection requires significant space and the cost and funding of acquiring land can be expensive.
At the same time, it is also important to consider how proposed flood adaptation strategies can adapt over time, and work together with other strategies. For instance, nature-based solutions (NBS) can be utilized as a stand-alone approach or alongside more conventional approaches to reduce risk. Ensuring there are multiple layers of defence can increase resilience, reduce direct cost related to the implementation of coastal adaptation projects, and provide multiple co-benefits, e.g., recreational activities and pollution abatement or by supporting coastal community livelihoods. Flood defences, such as dikes, groynes, and jetties can also be aesthetically and visually obstructive or displeasing. As such, adaptation strategies that utilize these approaches should include significant local stakeholder input to ensure that there is adequate spatial integration of adaptation solutions within the broader landscape context. This can serve to foster the integration of both recreational functions and the provisioning of food and energy production alongside flood protection.
A Values-Based Approach
Community perception of risk is also an important consideration for formulating and implementing effective coastal adaptation policy and practice. This is because risk perception is shaped by individual attitudes and basic beliefs related to the value of ecosystems. More importantly, risk perception has been linked directly to adaptation outcomes because higher levels of ecological values have correlated positively with higher perceptions of risks. Perceptions of higher levels of risk can contribute a heightened sense of community thereby preparing littoral populations to be more responsive to adapt to coastal changes. Community buy in is also critical for ensuring favourable outcomes among diverse groups, to achieve win-win solutions and to prevent conflicts between competing coastal interests. Therefore, adaptation approaches should include community-based risk assessment that consider incorporating community cultural values, equitable social relations and engagement that focus on joint learning, and the generation of trust and commitment. These serve as underlying forces that contribute to effective and equitable collaborative coastal management processes.
Browse Strategies
Amphibious architecture is an adaptation strategy where structures are designed to adapt to flooding.
Located offshore, barrier islands are dynamic landforms that are formed from offshore bars and, spits.
Beach nourishment (beach renourishment, beach replenishment, or sand replenishment) involves a process of replacing material (usually sand) to a beach that might have been lost by longshore drift or erosion.
Breakwaters are linear, offshore, or onshore structures built to protect the coast from the effects of both storm surges and longshore drift.
Coastal wetlands represent ecosystems that are permanently or seasonally inundated with either fresh, brackish, or saline water that is usually less than 6 feet in depth at low tide.
Development permits regulate land use to ensure that areas are developed in a manner that aligns with environmental protection and the protection of ecosystems, biodiversity.
Transfer of Development Rights (TDR), also commonly referred to as Transfer of Development Credits (TDC), is a mechanism that is used to encourage high-density development on lands that are less susceptible to the impacts of built infrastructure within a defined region, while limiting development on ecologically sensitive lands.
Dikes are linear compacted earth structures implemented to protect coastal areas from flooding.
Dry floodproofing is a practice of utilizing waterproof membranes and other types of sealants to prevent floodwater from entering a building.
Dunes develop from sand deposits that represent a store of sediment in the zone just landward of normal high tides.
An easement or covenant is a legal agreement that allows the owner of a parcel of land to grant rights to others for a designated use.
Emergency planning and preparedness is a coordinated process that involves assessing the likely impacts of a disaster event and coordinating a set of responses to reduce or prevent property damage.
Evacuation routes are accessways that are constructed above flood levels and that connect flood risk areas to mainland areas that are safely above flood plains.
Floodwalls are typically vertical structural barriers that are used in locations where space is limited due to buildings or other land uses.
In British Columbia, the foreshore is defined as the land that exists between the low and high watermarks of a stream, river, lake, or ocean.
Groynes are rigid structures, typically constructed using heavy materials extending from the upper shore to the water.
Land acquisition is the process of purchasing or expropriating land with the primary purpose of protecting the public interest.
A land trust is a non-profit private organization created for the purpose of environmental conservation.
Zoning is a process that gives local and national agencies the autonomy to regulate land use.
Reefs are under and near water ecosystems that provide protection against flooding and erosion.
Scours are property-specific structural tools that are used to protect shoreline structures or building foundations from exposure to the corrosive effects of moving water.
Seawalls are hard engineered structures built parallel to the shoreline.
Secondary dikes work in conjunction with primary dikes to reduce the impact of a flood if the primary dike is breached.
Storm surge barriers are heavily engineered movable or fixed barriers/gates that are closed to prevent flooding during bad weather forecasts.
A subdivision regulation is a planning tool that can be used to establish conditions for the protection against environmental hazards, e.g., coastal hazards related to sea-level rise.
Early warning systems form an important element of disaster risk management.
Wet floodproofing is the measure of allowing water to enter and exit a structure with minimal or no damage.