Coastal Management Policy Research Articles

Modeling Impact of Intertidal Foreshore Evolution on Gravel Barrier Erosion and Wave Runup with XBeach-X

This paper provides a sensitivity analysis around how characterizing sandy, intertidal foreshore evolution in XBeach-X impacts on wave runup and morphological change of a vulnerable, composite gravel beach. The study is motivated by a need for confidence in storm-impact modeling outputs to inform coastal management policy for composite beaches worldwide. First, the model is run with the sandy settings applied to capture changes in the intertidal foreshore, with the gravel barrier assigned as a non-erodible surface. Model runs were then repeated with the gravel settings applied to obtain wave runup and erosion of the barrier crest, updating the intertidal foreshore from the previous model outputs every 5, 10 and 15 min, and comparing this with a temporally static foreshore. Results show that the scenario with no foreshore evolution led to the highest wave runup and barrier erosion. The applied foreshore evolution setting update is shown to be a large control on the distribution of freeboard values indicative of overwash hazard and barrier erosion by causing an increase (with 5 min foreshore updates applied) or a decrease (with no applied foreshore updating) in the Iribarren number. Therefore, the sandy, intertidal component should not be neglected in gravel barrier modeling applications given the risk of over- or under-predicting the wave runup and barrier erosion.

Assessing the Effectiveness of Coastal Marine Protected Area Management: Four Learned Lessons for Science Uptake and Upscaling

For almost two decades, marine protected areas (MPAs) have been a central instrument of coastal conservation and management policies, but concerns about their abilities to meet conservation goals have grown as the number and sizes of MPAs have dramatically increased. This paper describes how a large (15 year) program of transdisciplinary research was used to successfully measure MPA management effectiveness (ME) - how well an MPA is managed, how well it is protecting values, and how well it is achieving the various goals and objectives for which it was created. This paper addresses the coproduction and uptake of monitoring-based evidence for assessing ME in coastal MPAs by synthesizing the experiences of this program conducted with MPA managers. I present the main outcomes of the program, many were novel, and discuss four ingredients (learned lessons) that underpinned the successful uptake of science during and after the research program: (i) early and inclusive co-design of the project with MPA partners and scientists from all disciplines; (ii) co-construction of common references transcending the boundaries of disciplines, and standardized methodologies and tools; (iii) focus on outcomes that are management-oriented and understandable by end-users; and (iv) ensuring that capacity building and dissemination activities occurred during and persisted beyond the program. Standardized monitoring protocols and data management procedures, a user-friendly interface for indicator analysis, and dashboards of indicators related to biodiversity, uses and governance, were the most valued practical outcomes. Seventy-five students were trained during the projects and most of the monitoring work was conducted with MPA rangers. Such outcomes were made possible by the extended timeline offered by the three successive projects. MPA managers’ and scientists a posteriori perceptions strongly supported the relevance of such collaboration. Local monitoring and assessment meets the needs of MPA managers and forms the basis for large-scale assessments through upscaling. A long-term synergistic transdisciplinary collaboration between coastal MPA managers and research into social-ecological systems (SESs) would simultaneously i) address the lack of long-term resources for coastal monitoring and SES-oriented research; ii) increase science uptake by coastal managers, and iii) benefit assessments at higher levels or at broader geographic scales.

Trends in Tidal Levels and Mean Sea Level in the Gulf of Thailand

Astronomical tides have a major impact on coastal sediment distribution, seawater levels, coastal navigation, and other coastal dynamics. Any significant change to tides could have impacts on coastal ecosystems. This study explored the hourly water level from 11 tidal gauge stations along the Gulf of Thailand over different periods using harmonic analysis. Secular trends of tidal levels, tidal range, mean sea level and tidal constituents were assessed using a linear regression model. We found changes in all the tidal levels assessed. Increasing trends were observed for almost all tidal levels and the mean sea level at all locations. At most of the locations, the trends in tidal levels were similar to the mean sea level. Widespread increasing trends were observed in relation to the tidal levels, and in most cases, the trends were consistent with the mean sea level. Analysis of the tidal harmonic constituents showed significant trends for the luni-solar diurnal constituent (K1) at most stations. However, the magnitude of the trends in the harmonic constituents was less pronounced compared to the trends in water levels. Coastal management policies should take into account these widespread changes in tides.

Evaluation of coastal vulnerability and exposure to erosion and submersion risks in Bou Ismail Bay (Algeria) using the coastal risk index (CRI)

The Algerian coastal zone is under high pressure occurring from natural origin (seismic and tsunamis risks, erosion/accretion, salt water intrusion, etc.) and from human sources (pollution, loss of biodiversity, economic value, etc.). The lack of data, particularly time series over natural coastal process, is an impediment for decision making. In many cases, the implemented coastal protection measures even exacerbate the vulnerability of these zones, particularly the hard engineering solutions. The aim of this work is to produce coastal vulnerability and exposure index maps to erosion and marine submersion, by adapting the coastal vulnerability index (CVI) into coastal risk index (CRI) according to the new vision of the risk adopted by the International Panel on Climate Change (IPCC). This index turned out to be a relevant tool to adjust coastal planning and management decision making, by confirming the vulnerability of some physiographic units and give at local and regional levels a broad image of coastal zone sensitivity to erosion and submersion. This index should be integrated in Integrated Coastal Zones Management policy and management decision making. The mapping of coastal vulnerability and exposure in Bou Ismail Bay shows that it is 80% moderately vulnerable to erosion and submersion. Also, 45% of the bay is highly exposed to coastal hazards. Some sectors are more vulnerable and exposed than others especially in the East side of the bay. The mapping of coastal risk index using coastal hazard component, combined with vulnerability and exposure maps, has led us to identify the degree of erosion and submersion risk in Bou Ismail Bay. The risk mapping shows that 40% of the bay is at high risk level; it means that some procedures should be made to decrease the level of sensitivity and improve resilience of this heavily populated area.

Numerical Modelling of Artificial Sediment Nourishment Impacts

Coelho, C.; Ferreira, M., and Marinho, B., 2020. Numerical modelling of artificial sediment nourishment impacts. In: Malvarez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 209–213. Coconut Creek (Florida), ISSN 0749-0208.In general, coastal erosion problems are related to significant sediments deficits. A possible coastal erosion mitigation strategy involves restoring the sediments balance through artificial nourishments. However, the complexity of the physical processes in the coastal zones challenges the numerical tools prediction capacity. This is usually overcome through numerical modelling of the shoreline evolution and the cross-shore profile along time, as an attempt to anticipate the performance of nourishments operations. The coastal morphology depends on the sediments dynamics and the incident wave climate is considered the main modelling agent responsible for the potential sediment transport capacity. The cross-shore sediment transport is usually associated to the shortterm behaviour of the morphological evolution of the beach (seasonal changes) and the longshore sediment transport is related to the long-term changes (towards an equilibrium state). Typically, these distinct sediment transport components are studied and modelled separately due to the incompatibility of their time scales of interest.This work was developed to numerically model the impact of artificial nourishments. LTC (Long-Term Configuration, Coelho, 2005) and CS-model (Larson et al., 2016) were both applied to analyse the spatial and temporal distribution of sediments induced by artificial nourishments along and across the shore, considering different intervention scenarios. LTC was applied to evaluate the nourishments impact in the shoreline evolution and to quantify the volume of nourished sediments in different longshore locations along time. The CS-model was used to analyse the performance of multiple intervention scenarios, varying the cross-shore location, frequency and volume of the artificial nourishments. The performance of this type of intervention generally represents a smaller shoreline retreat and an increase of the cross-shore profile volumes during a limited period of time. The project results aim to increase numerical modelling capabilities, helping on the selection of optimal artificial nourishment schemes and the establishment of more efficient coastal management policies.

Assessing anthropogenic vulnerability of coastal regions: DEA-based index and rankings for the European Atlantic Area

This paper aims to assess the vulnerability of coastal areas to sectoral pressures from maritime-related socio-economic activities. To do this, a DEA-based method is proposed to construct a synthetic index of anthropogenic vulnerability with which to rank European Atlantic Area countries and regions down to a regional scale below the national level. The set of indicators selected for this index focuses on five important vectors: marine spills, port activities, tourism, protection of natural areas, and water quality and waste management. The paper shows that, overall, the United Kingdom has the most vulnerable coast in Atlantic Europe, with Ireland showing the most resilient coast of all. Furthermore, the proposed method also allows one to identify peer groups with the same vulnerability pattern. Thus, policies aiming to reduce the vulnerability of a target region may be devised by focusing on the least vulnerable regions within the relevant group. The detailed analysis presented may help regional policy makers as a diagnostic tool to detect and assess vulnerability weaknesses so that they can design and carry out appropriate actions in line with integrated European coastal management policies.

Choice experiments to elicit the users’ preferences for coastal erosion management: the case of Praia da Amorosa

Coastal erosion is a complex and increasingly important problem, largely due to its effects and management strategies. The current context of climate change, together with centuries of human occupation of shorelines, adds pressure for the development of sustainable coastal management policies, the success of which crucially depends on the consideration of all stakeholders’ perspectives. This research investigates users’ preferences over alternative options of coastal erosion management. Through the implementation of a discrete choice experiment, respondents’ preferences regarding management alternatives are elicited, and their willingness to pay for alternatives’ attributes is estimated. The results show that respondents prefer some interventions to mitigate the problem rather than no action, and prefer lighter intervention (palisades, gangways) to heavy infrastructures (rockfills, seawalls, groynes). Moreover, the results show the presence of preference heterogeneity and thus the need to use more flexible and complex models. Based on the results obtained, it is possible to drive some policy implications. First, the do-nothing option is not viable from the population’s standpoint; second, although some type of coastal erosion protection is demanded by the general population, the preferred approach is for light forms, contrary to the policy adopted in the last century, and still overwhelmingly present in the territory. Lastly, given the considerable heterogeneity in respondents’ preferences, careful consideration of the welfare impact of coastal interventions by population segments is required.

Beach nourishment practice in mainland Portugal (1950–2017): Overview and retrospective

A compilation of all beach nourishment projects conducted along mainland Portugal was made, totalizing 134 interventions up until 2017. The objectives, type of deposition, borrow area, responsible entities and geographic distribution of each intervention were identified and are herein briefly presented and discussed. Beach nourishments were mostly carried out to improve the stability of the coastline, as a mitigation measure for coastal erosion, and to increase beach width for recreational use, as a tool for adding value to the coast. Operations concentrated in: 1) urban areas where erosion can pose risks to people and assets, 2) close to river mouth/inlets where port structures are established, and 3) touristic areas with high recreational value. Port Administrations contributed most (in number and volume) for the nourishment operations (62% of all operations), favouring the placement of the dredged sediments on the nearshore, and, more recently, providing the sediment of opportunity for subaerial beach fills and/or dune reinforcement carried out in cooperation with the State Environment/Coastal Authorities. The increase in the number of beach nourishments was accompanied by a decrease in the number of "hard" coastal structures, concurring to the optimization of an integrated coastal sediment management policy, in a clear paradigm shift that started in the 90s in regard to the coastal protection/defence strategy. There is a growing awareness regarding the beneficial use of sediments dredged by Ports to counter the coastal sediment deficit, making coastal nourishments mainly supply-driven in mainland Portugal. Beach nourishment practice has evolved to be the major contributor to a regional and national-scale coastal protection strategy focused on coastal sediment management.

Uncovering climate (in)justice with an adaptive capacity assessment: A multiple case study in rural coastal North Carolina

Climate change resilience is an area of praxis where efforts to enhance community adaptive capacity are informed by theory. However, there is growing evidence that ethnocentrism and privilege are shaping coastal management policies while many communities with climate justice issues struggle to build resilience. Particularly, rural coastal communities, contrasting urban areas, have limited access to centralized planning efforts, unique local contexts for outreach, compounding social vulnerabilities (job loss, out-migration, limited social services), and receive less attention from resilience researchers. Following calls to integrate climate justice into resilience praxis, we assess perceptions of adaptive capacity within predominately African American communities in a rural low-lying coastal region in eastern North Carolina. We add a climate justice lens to evaluate the previously-validated Rural Coastal Community Resilience (RCCR) framework. The RCCR is intended to improve planning efforts by providing climate change information, initiating conversations, and contributing to resilience theory. In contrast to its previous applications, engagement led to declines in perceived adaptive capacity. This result highlights that the information sharing goals of the engagement efforts were poorly aligned with community concerns and threat perceptions. Additionally, perceived climate injustices emerged revealing instances of adaptation oppression. This study recommends strategies to rethink traditional extension efforts to improve inclusiveness by deeply interrogating the inherent whiteness of standard modes of communicating climate science.

Use of an environmental diagnostic study on a coastal lagoon as a decision support tool for environmental management policies in a coastal zone

Purpose An efficient and adequate environmental monitoring plan is essential to any integrated coastal zone management (ICZM) program. The purpose of this paper is to apply an environmental diagnostic study to a coastal lagoon using anthropogenic markers as a decision support tool to aid the development of coastal environmental management policies. Design/methodology/approach Specifically, environmental status and anthropogenic sources were determined as part of a coastal environmental management plan; a study of human occupation and use was conducted to determine the predominant human activities around the lagoon; an environmental diagnostic study was conducted to determine the occurrence, levels and distribution of markers; and the results of the environmental diagnostic study were compared to indicators stipulated in Brazilian legislation. Findings Land use study revealed both urban and rural activities around the lagoon, as evidenced by the existence of residences, restaurants as well as poultry and livestock activities. The environmental diagnostic study revealed the input of human sewage (treated and raw) and runoff from animal husbandry activities. Practical implications The information produced using anthropogenic markers showed the influence of less studied rural activities, such as livestock and poultry farming, thereby providing a more reliable environmental status compared to the use of classic indicators employed in laws issued by international and Brazilian agencies. Originality/value The present results show that classic indicators used by environmental agencies are insufficient for an accurate diagnosis of coastal zones with multiple anthropogenic activities. Thus, the modernization of the environmental monitoring plan of the ICZM program is urgently needed for a more accurate assessment of coastal environments.

ANALISIS KERENTANAN PENGELOLAAN WILAYAH PESISIR DITINJAU DARI PRESPEKTIF MITIGASI BENCANA DI KABUPATEN BADUNG PROVINSI BALI

The vulnerability identification of coastal areas in this study consisted of the level of danger (earthquake and tsunami), physical vulnerability and non-physical vulnerability. Determination of hazard level using modeling based on seismic history in the subduction zone south of Bali, while analysis of the level of physical and non-physical vulnerability is used Descriptive analysis and Analytical Hierarchy Process (AHP). The analysis process will determine the ranking used as an indicator of decision making to create a vulnerability level map in the research area through the Geographic Information System (GIS) with three levels, namely high, medium and low. In this study also formulated coastal area management policies in the perspective of disaster mitigation using SWOT analysis. The results of the analysis show that four kelurahan in Badung Regency which have high levels of vulnerability are Kuta, Tuban, Kedonganan and Tibubeneng. While the seven kelurahan in the medium level of vulnerability are Jimbaran, Benoa, Tanjung Benoa, Legian, Seminyak, Canggu, Dalung, and the four kelurahan with low levels of vulnerability are Pecatu, Ungasan, Kutuh and Kerobokan. In general the research area is at a high to moderate level of vulnerability, this shows that a comprehensive disaster mitigation effort is needed by implementing several strategies formulated, including 1) developing disaster resilient village programs by establishing disaster risk reduction forums and volunteer training villages for disaster mitigation, 2) maximizing community knowledge in disaster and mitigation to cope with high earthquake and tsunami hazard levels, 3) implementing regional regulations on disaster mitigation based spatial planning effectively in controlling disaster risk areas and utilizing green lines as evacuation routes and meeting point.

Defining Coastal Resilience

The concept of resilience has taken root in the discourse of environmental management, especially regarding Building with Nature strategies for embedding natural physical and ecological dynamics into engineered interventions in developed coastal zones. Resilience is seen as a desirable quality, and coastal management policy and practice are increasingly aimed at maximising it. Despite its ubiquity, resilience remains ambiguous and poorly defined in management contexts. What is coastal resilience? And what does it mean in settings where natural environmental dynamics have been supplanted by human-dominated systems? Here, we revisit the complexities of coastal resilience as a concept, a term, and a prospective goal for environmental management. We consider examples of resilience in natural and built coastal environments, and offer a revised, formal definition of coastal resilience with a holistic scope and emphasis on systemic functionality: “Coastal resilience is the capacity of the socioeconomic and natural systems in the coastal environment to cope with disturbances, induced by factors such as sea level rise, extreme events and human impacts, by adapting whilst maintaining their essential functions.” Against a backdrop of climate change impacts, achieving both socioeconomic and natural resilience in coastal environments in the long-term (>50 years) is very costly. Cost trade-offs among management aims and objectives mean that enhancement of socioeconomic resilience typically comes at the expense of natural resilience, and vice versa. We suggest that for practical purposes, optimising resilience might be a more realistic goal of coastal zone management.

Monitoring changes in land use and distribution of mangroves in the southeastern part of the Mekong River Delta, Vietnam

Mangroves are one of the most valuable and productive coastal ecosystems. Previous studies show a severe loss of mangroves around the world over the last several decades due to natural and anthropogenic activities. Mangroves located in the southeastern part of the Mekong River Delta (MRD) are also affected by these activities. Shrimp farming is considered as one of the main drivers causing the rapid loss and degradation of mangroves. The goal of this study is to assess the spatiotemporal changes in land use and distribution of mangroves in the Soc Trang and Bac Lieu provinces of the southeastern part of the MRD. Multi-temporal Landsat data were used for land use and land cover (LULC) classification using the maximum-likelihood classification algorithm. The changes in mangrove forest areas were monitored using medium spatial resolution (Landsat-5 Thematic Mapper and Landsat-8 Operational Land Imager) satellite imageries from 1988 to 2018. In the study area, there were seven major LULC types namely, dense mangroves, sparse mangroves, aquaculture farms, arable land with crop cover, arable land without crop cover, settlements, and water bodies. The overall accuracies of the LULC maps in 1988, 1998, 2008, and 2018 were 81.2%, 83.3%, 78.3%, and 81.9%, respectively. This study reveals that dense and sparse mangrove forests have decreased by 90% from 5495 hectares (ha) to 515 ha and by 55% from 14,105 to 6289 ha, respectively from 1988 to 2018. On the other hand, the aquaculture farm has increased at the rate of 5024 ha/year for a period of 30 years. This rapid growth of aquaculture farming activities caused the rapid loss and degradation of mangroves in the MRD. Quantitative information about mangrove change obtained by this study is considered to be useful for future coastal management and relevant policies in the MRD.

Socio-ecological Mobility: A Research Strategy for a New Coastline

Persistent development, population pressures, and increasing natural hazards are unequivocally changing socio-ecological systems in the coastal zone. This essay provides direction and initiates scientific dialog on the potential role of mobility in adapting to natural and social changes in coastal environments. The essay identifies four key research areas on information needed to develop coastal management actions and policies that support and recognize socio-ecological coupling in coastal areas. The proposed research includes: (1) modeling localized scenarios that illustrate the tradeoffs associated with various sea level rise adaptation, (2) assessing and consolidating mobility terminology for different applications and contexts, (3) developing solutions to synchronize the co-migration of natural environments and built infrastructure, and (4) evaluating existing or creating new transparent, equitable, and sustainable policies and incentives to support socio-ecological mobility by using case studies and social science methods to understand how people make mobility decisions in different contexts.

Pattern and scale: evaluating generalities in crab distributions and marsh dynamics from small plots to a national scale.

The generality of ecological patterns depends inextricably on the scale at which they are examined. We investigated patterns of crab distribution and the relationship between crabs and vegetation in salt marshes at multiple scales. By using consistent monitoring protocols across 15 U.S. National Estuarine Research Reserves, we were able to synthesize patterns from the scale of quadrats to the entire marsh landscape to regional and national scales. Some generalities emerged across marshes from our overall models, and these are useful for informing broad coastal management policy. We found that crab burrow distribution within a marsh could be predicted by marsh elevation, distance to creek and soil compressibility. While these physical factors also affected marsh vegetation cover, we did not find a strong or consistent overall effect of crabs at a broad scale in our multivariate model, though regressions conducted separately for each site revealed that crab burrows were negatively correlated with vegetation cover at 4 out of 15 sites. This contrasts with recent smaller-scale studies and meta-analyses synthesizing such studies that detected strong negative effects of crabs on marshes, likely because we sampled across the entire marsh landscape, while targeted studies are typically limited to low-lying areas near creeks, where crab burrow densities are highest. Our results suggest that sea-level rise generally poses a bigger threat to marshes than crabs, but there will likely be interactions between these physical and biological factors. Beyond these generalities across marshes, we detected some regional differences in crab community composition, richness, and abundance. However, we found striking differences among sites within regions, and within sites, in terms of crab abundance and relationships to marsh integrity. Although generalities are broadly useful, our findings indicate that local managers cannot rely on data from other nearby systems, but rather need local information for developing salt marsh management strategies.

Coastal management in Portugal: Practices for reflection and learning

Portugal is located in the southwest of Europe. From economic, cultural, social and environmental point of views, Portuguese coastal areas face multiple challenges related to the coastal management policy, the functionality of the governmental services and the responses to the society, in particular, to the affected citizens. Qualitative and quantitative understanding of the coastal morphological processes is necessary, as it is a precondition for a successful coastal management approach. This paper aims to provide a general overview of the recent morphological coastal development in Portugal, summarize some past experiences on coastal protection and identify potential problems and challenges as an attempt to support an integrated coastal management policy that can be applied in Portugal and other countries facing the same difficulties to mitigate and manage coastal erosion. Special focus is given to the legal status and policy on coastal monitoring, by analyzing the administration responsibilities concerning coastal management, legislation and regulations, as well as policy tools schemes, built into the legal structure with different levels of hierarchy. The manuscript ends with a brief analysis of some future coastal protection measures that are part of a national coastal adaptation strategy proposed to fulfill a set of goals to be established by 2050.

Uncertain seas: probabilistic modeling of future coastal flood zones

ABSTRACTFuture sea-level rise will likely expand the inland extent of storm surge inundation and, in turn, increase the vulnerability of the people, properties and economies of coastal communities. Modeling future storm surge inundation enhanced by sea-level rise uses numerous data sources with inherent uncertainties. There is uncertainty in (1) hydrodynamic storm surge models, (2) future sea-level rise projections, and (3) topographic digital elevation models representing the height of the coastal land surface. This study implemented a Monte Carlo approach to incorporate the uncertainties of these data sources and model the future 1% flood zone extent in the Tottenville neighborhood of New York City (NYC) in a probabilistic, geographical information science (GIS) framework. Generated spatiotemporal statistical products indicate a range of possible future flood zone extents that results from the uncertainties of the data sources and from the terrain itself. Small changes in the modeled land and water heights within the estimated uncertainties of the data sources results in larger uncertainty in the future flood zone extent in low-lying areas with smaller terrain slope. An interactive web map, UncertainSeas.com, visualizes these statistical products and can inform coastal management policies to reduce the vulnerability of Tottenville, NYC to future coastal inundation.

Developing a nature-based coastal defence strategy for Australia

ABSTRACTAustralia’s rapid coastal population growth coupled with the increased risk of hazards driven by climate change creates an urgent need to start adaptation planning for the future. The most common solutions for protecting the coast (seawalls, breakwaters) are expensive and non-adaptive (i.e., they need to be rebuilt, upgraded and maintained in response to a changing climate). There is international precedence for the development of nature-based solutions (i.e., the integration of natural habitats such as coastal vegetation and biogenic reefs) as a cost-effective and sustainable approach to shoreline protection from erosion and flooding. The development of nature-based approaches has been supported by large interdisciplinary teams to inform policy and decision-making. Nature-based coastal defence is currently not a tool widely used in Australia. Key to their wider implementation is: (1) improved scientific knowledge; (2) effective governance; and (3) social acceptance. Recently implemented pilot trials need to inform industry-accredited guidelines that can be integrated into coastal management and government policy.

Climate change and coastal policy: the need to address erosion-flooding interactions for effective coastal risk management

ABSTRACTGlobal climate change is giving rise to a world characterised by novel human-environment interactions. At the coast, higher than average population growth, concentrated within static conurbations means that climatic changes here are likely to generate high-risk outcomes. Coastal erosion and flooding are two such outcomes with the potential to cause trillions of pounds worth of losses in the near future. Many studies have sought to quantify the extent of erosion and flooding in various locations. However, there is a lack of research into the interaction between erosion and flooding. This article explores the importance of erosion-flooding interaction for effective coastal risk management policy. Blakeney Point, a mixed sand-gravel barrier on the UK's North Norfolk coast, is used to explore three expressions of erosion-flooding interaction: the role of coastal morphology, the importance of shoreline position, and the occurrence of extreme storm events. At Blakeney Point, and elsewhere, the potential for unforeseen risk-generating scenarios suggests that erosion- flooding interaction ought to be incorporated into future coastal risk management policy.

Factors Influencing Landowners’ Decisions for Income-Generating Activities on Private Coastal Wetland in Louisiana

The coastal zone of Louisiana contains more than 3 million wetland acres and has the highest acreage of salt marsh of any state. However, Louisiana accounts for 80 percent of the nation’s coastal land loss. The loss of Louisiana’s coastal wetlands results in changes in economic and ecological benefits on local communities. The purpose of the study is to investigate the factors that motivate private coastal landowners to participate in income-generating activities and the level of income derived from their coastal wetland parcels and to gauge their opinion of potential policy instruments for coastal wetlands stewardship. A double-hurdle model was applied to econometrically identify the determinants on the participation and level of participation in income-generating activities using data collected from a sample of coastal wetland owners. The results based on the estimated parameters and marginal effects revealed that decisions to participate and the level of participation are related to physical characteristics of the wetland and socioeconomic characteristics of the landowner. For example, the type of wetland is the primary factor influencing the decision to participate and the level of participation. In addition, understanding the landowner’s attitude toward wetland restoration program provides the opportunity for policymakers to better evaluate current and potential policies for coastal management in Louisiana.