An Integrated Framework to Analyze Local Decision Making and Adaptation to Sea Level Rise in Coastal Regions in Selsey (UK), Broward County (USA), and Santos (Brazil)

One of the clear signals of the ongoing climate change is sea level rise (SLR). Normal oceanic tides superimposed on a rising sea level and coastal flooding will affect many coastal communities. An international collaboration among Brazil, the United Kingdom, and the United States was designed to evaluate local decision making processes and to open space for local urban managers to reflect on possible actions toward adaption to sea level rise given the historical constraints imposed by administrative and institutional structures. This project focused on the processes that shape adaptation of three coastal communities in three countries. It worked jointly with these communities in defining the problem, examining risks, and understanding the benefits and obstacles that may hinder implementation of adaptation options. The framework was co-designed by an interdisciplinary team that incorporated social and natural scientists from the three countries, including local government How to cite this paper: Marengo, J., Muller-Karger, F., Pelling, M., Reynolds, C.J., Merrill, S.B., Nunes, L.H., Paterson, S., Gray, A.J., Lockman, J.T., Kartez, J., Moreira, F.A., Greco, R., Harari, J., Souza, C.R.G., Alves, L.M., Hosokawa, E.K. and Tabuchi, E.K. (2017) An Integrated Framework to Analyze Local Decision Making and Adaptation to Sea Level Rise in Coastal Regions in Selsey (UK), Broward County (USA), and Santos (Brazil). American Journal of Climate Change, 6, 403-424. https://doi.org/10.4236/ajcc.2017.62021 Received: March 23, 2017 Accepted: June 25, 2017 Published: June 28, 2017

officials. The study addressed 1) evaluation of adaptive capacity through participant surveys and 2) physical and cost impact simulations using geospatial models of the built infrastructure and implementation of adaptation options under different hazard scenarios, including 50 and 100-year sea level rise projections and severe storms. Based on the surveys' results, there is a clear sense of the awareness of each community of the risk of floods due to intense storms, and of the usefulness of engaging early in a process that promotes the understanding of risks, impacts, and costs. A majority of workshop participants prioritized pursuing physical and green infrastructure actions now or within coming years or decades. A positive common aspect of the three sites was the commitment shown by the stakeholders in taking part in the process and evaluating which adaptation measures could be more effective in their cities. While in the US and UK structural solutions and voluntary buyouts were prioritized for the future, Brazil prioritized structural solutions and ecosystems restoration and not voluntary buyouts. All of these are choices to increase resiliency against sea level rise that have a high benefit-cost ratio. The Adaptive Capacity Index (ACI) results illustrate barriers to adaptation action, including technical, economic and political issues that reveal inequalities in adaptive capacity among case studies.

Keywords
Sea Level Rise, Vulnerability, Adaptation, Impacts, Climate Change

Introduction
Coastal areas of the world continue to show a faster rate of population growth than inland continental settings [1]. Coastal communities in low-lying geographic settings are especially vulnerable to hazards related to continuing sea level rise (SLR) and superimposed tidal variations and storm surges. Nearly 7% of human communities are in areas where elevation is less than 5 meters from historical sea level [2]. Most of the world's 60 million poor that live in low elevation areas reside in just 15 countries, including Brazil, the United States of America (USA) and the United Kingdom (UK) [3] [4]. Of these, approximately 40 million are exposed to major flood risks, and these risks are expected to increase over the next 50 years.
Severe flooding hazards are expected to increase along trailing edge of tectonic plates where there are a larger number of low-lying areas compared to more scattered areas on active tectonic margins. Along the Atlantic coasts of Central and South America, SLR between 1950 and 2008 has ranged from about 2 to 7 mm·yr −1 [5]. Extreme coastal flooding events are becoming more frequent, with impacts on coastal urban areas and changing patterns of coastal erosion. A gradual increase in average sea level of 1 m, often cited as a possible scenario within a 100-year timeframe [6] [7], would seriously affect some coastal populations in Brazil [8], the USA, and the UK [9] [10]. Damages are compounded when tidal fluctuations and surges due to severe storms are superimposed on these esti-mates.
Recent studies on climate adaptation enhance the importance of engaging or activating communities and supporting community roles in understanding climate change and adaptation needs [11]. Responses from cities to improve their resilience are urgent but policymakers need to understand current adaptation to plan comprehensively and spend effectively [12].
To evaluate how local government may respond to risks associated with SLR projections, a group of natural and social scientists from the USA, UK, and Brazil developed the METROPOLE project. METROPOLE is an effort to develop an integrated framework to analyze local decision-making and the adaptive capacity of communities facing environmental change.
The hypothesis of the METROPOLE team was that risk knowledge is best understood when it is co-produced with science and within social, political and cultural contexts. We analyze social context factors that affect adaptation planning and policy changes (adaptive capacity) and responses by local stakeholders when presented with interactive computer-based scenario simulations of SLR and impacts in participatory planning meetings. This study summarizes the results of efforts to evaluate local decision making processes concerning possible actions toward adaption to SLR and storm surge in communities in the UK, US and Brazil.

Case Studies
The METROPOLE team sought an initial understanding of residents' perception of coastal vulnerability associated with climate change risks and adaptation capacity in different communities with different social, political, and cultural contexts. A range of potential threats associated with SLR was evaluated by use of

Methods
To help stakeholders in each community to assess risk due to several SLR scena-

Surveys
Prior to each workshop, the METROPOLE team distributed a survey intended to

Adaptive Capacity Index (ACI)
Understanding the standards and base values of organizations playing a key role in climate change adaptation provides insight into how priorities are being set and what shifts in approach may be possible.
In this study, the adaptive capacity was evaluated through the ACI approach [16]. ACI is designed to measure and interpret institutional architecture and the flexibility of individuals that shape adaptive capacity and is derived from well-prepared face-to-face interviews. The ACI methodology has three components: 1) the index-a quantitative expression of adaptive capacity; 2) policy review, and 3), a learning tool-respondent can use the conversation through which the tool is delivered to reflect on current practice, goals and procedures. These components combined the objectivity suggested by an index, with a more nuanced analysis of policy options. The complementary components are designed to help move the adaptive capacity of the organizational landscape in a desired direction while providing an opportunity for participants to consider an organizational capacity for change [17].
The ACI provides a mechanism through which existing management priorities; organizational structures and governance can be reviewed at multiple scales with a view to identifying efficient pathways for mainstreaming adaptation. The process enabled local decision-makers and sector representatives to share experiences, insights and expected difficulties that may hinder efforts. The degree of adaptive capacity of the system depends on how a series of strategies, capabilities and available assets interact within a dynamic context to allow individuals, households, communities, organizations and institutions to cope with changes to their environment.
The ACI model has various subcomponents that form the underlying conceptual framework for the survey instrument: levels of capital (social and human, technological and economic); organization architecture, organizational re-sponsibility, ability to experiment, ability to learn, command over available resources, ability to plan for the future and critical self-reflection. In the surveys these subcomponents are divided into four main sections: 1) Risk Identification; 2) Risk Reduction; 3) Learning and 4) Adaptive Governance.
Sample frames were derived from decision-making organizations with responsibilities for short and long-lasting, potentially climate-impacted decisions and also from framework organizations whose actions set the frame for adaptive actions by a wider range of organizations. Organizations across government agencies, civil society and private entities throughout the landscape of sectors, including land use/planning/management, environment, emergency and risk management, transport, energy and water, economy, social structure and health were approached at each site.
To enhance the potential insight into adaptation practices, respondents were asked to comment on present-day organizational capacities, along with capacities at two previous times, in order to generate a trajectory over time. Results were evaluated in both quantitative and qualitative ways: the former produces a description of capacity from the viewpoint of respondents and can be presented for each respondent and in aggregate form. Interview data were also analyzed and coded qualitatively to draw out processes, gaps and opportunities to help improve analytical clarity and focus policy recommendations.

SLR and COAST Modeling
The team used the COastal Adaptation to Sea Level Rise Tool (COAST) developed by [18] and the first challenge was to find the appropriate input data at each location to make the risk and impact simulations. Risks and the associated costs were estimated using the COAST platform [19] [20] [21]. COAST estimates SLR and storm surge impacts, by calculating damage from storm surge events cumulatively over time, given a changing base water level. It then calculates relative benefits of various adaptation scenarios in terms of cumulative avoided damages over time. The model is designed to provide information to municipalities, state agencies and other groups interested in benefit-cost analysis for adaptation strategies aimed at reducing damages from SLR and storm surge.
COAST created data visualizations of coastal change based on SLR and superimposed storm surge events, to help users understand economic and environmental consequences of flooding scenarios.
COAST requires input on the time horizons to be simulated (e.g., 30, 100 years), projected SLR curves, vulnerable assets such as infrastructure including real estate and values per square meter and the types of actions that a community would take (moving and rebuilding on higher ground, fortification such as seawalls, etc.). COAST computed financial impacts using inputs from local stakeholders and engineers.
Different SLR curves and estimates of extreme flood heights and the time horizon for evaluating impacts at each location were selected by each of the communities as provided by local authorities and regional studies [9] [10] [22]. The observed sea level is a composite of tide and surge, the former being due to astronomical effects and the latter due to meteorological influence.

Adaptation Scenarios for COAST Modeling
In each case study, two scenarios were analyzed for mid and end of 21th Century SLR projections. One scenario evaluated vulnerability if "no action" is taken by the community and infrastructure remained as it is at present. Another scenario evaluated a range of adaptation measures proposed by local communities during the METROPOLE engagement workshops. To apply the COAST model for each community, we incorporated datasets from nationally or regional accepted sources (see Methods section).
Municipal contacts and local experts determined that the assessments needed to include SLR projections for low and high scenarios for particular timeframes. The "no action" scenario is a baseline vulnerability assessment that was used for comparing the costs and benefits from various adaptation options. Benefit The benefit-cost ratio is calculated as the relation between benefit and cost of adaptation measures. A ratio lower than 1 suggests that adaptation measures would cost more than the avoided damages for both SLR scenarios; ratios higher than 1 suggest that the economic damages would be smaller with adaptation options implemented. For Santos, Table 2 shows that the economic damages in this region would be, for high and low SLR scenarios, respectively, nearly 24 to 29 times smaller with adaptation than damages projected if no action were taken. Similarly, for Broward County, the costs would be nearly 22 to 31 times smaller with adaptation than damages projected if no action were taken.
Broward County chose a specific adaptation scenario that included flood proofing, elevating structures and voluntary buyouts to protect commercial and residential real estate and government structures. Selsey chose to model different types of seawalls and combinations of seawall heights to protect residential areas.
Santos adopted dredging and mangrove restoration for its northwestern region, while for the Southeastern region reinforcement of existing walls and beach nourishment were the selected options.
Commercial buildings were not included in the list of properties. This represents an underestimate of risk and of damages. COAST also did not estimate damage from winds, erosion forces, or rainwater drainage backups, which might also cause building damage, substantially threaten health and other property, and changes local ocean circulation, salinity, etc., that may in turn also affect local sea level.

Sea Level Rise Impacts
The METROPOLE team worked jointly with a set of stakeholders in each community to evaluate risks and impacts of SLR with the COAST tool and evaluate  the disposition of the community to change using the ACI [16]. The process used the participatory approach of Daniels and Walker [29] and [30] to explore the complex issue of how communities of different cultural backgrounds respond to risk.

Adaptation Options Selected in the Three Case Studies
The community was able to change the possible scenarios to be evaluated with the COAST model, and examined the outcome of different adaptation scenarios (i.e. benefit-cost analyses). Figures 1-3   avoided damage over time. Floods clearly have more intense impacts over the long-term horizon at the three locations. SLR alone showed minimal to no flooding impacts in the modeled scenarios (data not shown). Selsey chose to model different types of seawalls and combinations of seawall heights to protect residential areas. Selsey currently has a substantial seawall, but no coastal topographic maps were available to input into the COAST model. Thus, the community decided only to evaluate the impacts of a 200-year storm, for which the assumption was that the existing seawall would not contain the flood. A 200-year flood in 2085 under low and high SLR scenarios would have impacts of order of US$42 and US$46 million, respectively ( Table 2). As indicated in the methods section, it was not possible to compute cumulative benefit-cost ratios for Selsey because of the lack of accurate topographic maps or a digital elevation model.
Broward County chose a specific adaptation scenario that included floodproofing, elevating structures, and voluntary buyouts to protect commercial and residential real estate and government structures. Elevating houses and floodproofing the coastline were among the choices, and were selected because they  (Table 2). In a high SLR scenario the costs would rise to US $518 million. By 2060, such damages under low and high SLR scenarios could approach US $620 million and US $860 million, respectively. Selsey chose to model different types of seawalls and combinations of seawall heights to protect residential areas. Selsey currently has a substantial seawall, but no coastal topographic maps were available to input into the COAST model.  (Table 2). As indicated in the methods section, it was not possible to compute cumulative benefit-cost ratios for Selsey because of the lack of accurate topographic maps or a digital elevation model. Santos adopted dredging and mangrove restoration for the northwestern sec-tor, while for the southeastern sector reinforcement of existing walls and beach nourishment were the selected options. The community evaluated beach nourishment, dune restoration, structural enforcement of existing sea-walls, water pumping and improvement of tide control gates in existing drainage canals. In the southeastern sector of the city the damages from a 100-year flood in 2050 under low and high SLR scenarios would be US $34 and US $38 million, while in 2100 these damages could reach US $60 and US $75 million, respectively ( Table   2).
Adaptation strategies chosen for planning were different in each of the three communities. In all cases, estimated costs and projected real estate losses were lower if particular adaptation actions were chosen compared to no-action scenarios. Table 2  The cumulative benefit (avoided damage) in Santos for the 100-year flood for 2010-2100 was US $242 million for the low SLR projection, and US $467 million for the high SLR scenario. In Santos, benefit-cost ratios ranged from 23.9 to 28.7 for the low and high SLR scenarios. For the high SLR scenario, every US $1.00 spent today in fortification was estimated to save US $28.70 by 2100.

ACI Analysis
Evaluating the ACI is an analytical process that engages a range of stakeholders in a comprehensive and thoughtful assessment of community resilience and ability to proactively seek change. The METROPOLE Project focused the ACI assessment on key actor organizations within the environmental risk scene.      (Table 3). Respondents associated this trend primarily with the establishment of the South Florida Regional Climate Change Compact (herein forward the "Compact"). The Compact has allowed factors such as the ability to learn and the ability to plan for the future, to be developed within the local governance structures and in the community.
The Compact has enabled focus on legislation and policy, which has propagated widely with positive effect among organizations, involved the establishment of key relationships in the region, and the ability to correct actions by analysis and observation of community impacts, was seen as the primary reasons for the consistent increase in adaptability scores over the decade.
In Santos, the ACI analysis showed some progression toward adaptability, but this was slow or stagnant in some factors (Table 3)

Conclusions
In this study we investigated how three coastal communities might consider actions for adaptation to climate change, taking into account geographical information, social factors and risk perceptions. These factors influence community resiliency and planning processes to cope with coastal flooding due to SLR, for example. METROPOLE investigated the collaborative processes of different communities in addressing risks to local ecological resources, infrastructure and quality of life, due to hazards derived from larger-scale forces, like sea level rise.
This project focused on the processes that shape adaptation of three coastal communities in three countries. It worked jointly with these communities in defining the problem, examining risks, and understanding the benefits and obstacles that may hinder implementation of adaptation options. The project participants co-designed methods to quantify vulnerability of coastal real estate, evaluated benefits and costs of adaptation options, quantified social attitudes about the implementation of these options, and explored methods of engaging the community.
The case studies of Broward County (USA) and Santos (Brazil) show that there are choices for increasing resiliency against sea level rise that have a high benefit-cost ratio. Specifically, these communities found that fortification of the coast, elevation of real estate and flood proofing are important investments that help mitigate higher costs due to flood risks 60 -100 years from now.
Based on the surveys' results, there is a clear sense from each community of the risk of floods due to intense storms and of the benefits of engaging as a community early in a process that helps people to understand risks, impacts and costs. A majority of workshop participants prioritized pursuing physical infrastructure and green infrastructure actions now or within the coming years or decades. This will have benefits that include a social and natural science basis and that address the local and regional social, political and cultural context. Assessment of the risks due to exposure and sensitivity of coastal communities to coastal flooding is essential for informing decision-making. Strategies to pro- previous flood studies; flood depth damage functions, etc.). It was initially assumed that substitutes for these inputs would be available elsewhere, but the experience with Santos and Selsey proved that realities are different.
The project had to tailor the assessment framework to each context. For example in the UK, tax assessment estimates of building value are only performed on residential properties and are for categories of buildings only, not for individual structures (therefore, commercial properties were not included in the analysis). Similarly, the US National Oceanic and Atmospheric Administration (NOAA) has developed consistent high-resolution LiDAR coverage of developed areas in all of the coastal US, but high-resolution LiDAR was difficult to find outside of the US. As a result, the lower-resolution imagery available in the UK did not recognize the existing seawall at Selsey. In Santos, the municipal contractor discovered that LiDAR tiles had been set at a variety of elevations without edge-matching, creating an unreliable mosaic. Corrections were made in each of these cases and others, but the patterns demonstrate the need for practitioners to maintain extreme flexibility, creativity and resourcefulness in conducting transnational research in adaptation to SLR and storm surge. Linking the ACI to evaluations conducted iteratively after implementing different COAST scenarios may help improve adaptation capacity.
METROPOLE was successful in that it galvanized interdisciplinary efforts among local actors in Selsey, Broward County and Santos, so that the cities can protect their buildings and population to cope with SLR consequent on climate change.
Categorizing the choices in coastal infrastructure for adaptation that are available to policy makers will allow for comparisons of their potential impacts on cities and ecosystems, and of their value in preparation for long-term SLR.
We have not gone that far in gaining insight into the advantages and disadvantages of different coastal infrastructure types, and how they might be applied in a given environmental and land-use context. However, the adaptations selected by the three communities may trigger governance processes that in the end will have a lasting effect on these communities. In Santos, scientific insights from the Nevertheless, as pointed out by the respondents of the ACI questionnaire, within the institutions the issue of adaptation is not being well conducted or even considered. Thus, the initial measures taken by the local government need to resonate in the key sectors of Santos, so that even in times of economic and political instability such as the present one, it can be recognized and internalized within organizations and the society as a whole, the urgency of adapting to the effects of sea level rise, as their consequences (like severe storm surges) are already in course, affecting Santos more strongly and more often.