Understanding changes in wave attenuation by emergent vegetation as wetlands degrade or accrete over time is crucial for incorporation of wetlands into holistic coastal risk management. Linked SLAMM and XBeach models were used to investigate potential future changes in wave attenuation over a 50-year period in a degrading, subtropical wetland and a prograding, temperate wetland. These contrasting systems also have differing management contexts and were contrasted to demonstrate how the linked models can provide management-relevant insights. Morphological development of wetlands for different scenarios of sea-level rise and accretion was simulated with SLAMM and then coupled with different vegetation characteristics to predict the influence on future wave attenuation using XBeach. The geomorphological context, subsidence, and accretion resulted in large predicted reductions in the extent of vegetated land (e.g., wetland) and changes in wave height reduction potential across the wetland. These were exacerbated by increases in sea-level from +0.217 m to +0.386 m over a 50-year period, especially at the lowest accretion rates in the degrading wetland. Mangrove vegetation increased wave attenuation within the degrading, subtropical, saline wetland, while grazing reduced wave attenuation in the temperate, prograding wetland. Coastal management decisions and actions, related to coastal vegetation type and structure, have the potential to change future wave attenuation at a spatial scale relevant to coastal protection planning. Therefore, a coastal management approach that includes disaster risk reduction, biodiversity, and climate change, can be informed by coastal modeling tools, such as those demonstrated here for two contrasting case studies.
NbS Approach: Disaster Risk Reduction
Ecosystem-based disaster risk reduction
Tropical beaches provide coastal flood protection, income from tourism, and habitat for flagship species. They urgently need protection from erosion, which is being exacerbated by changing climate and coastal development. Traditional coastal engineering solutions are expensive, provide unstable temporary solutions, and often disrupt natural sediment transport. Instead, natural foreshore stabilization and nourishment may provide a sustainable and resilient long-term solution. Field flume and ecosystem process measurements, along with data from the literature, show that sediment stabilization by seagrass in combination with sediment-producing calcifying algae in the foreshore form an effective mechanism for maintaining tropical beaches worldwide. The long-term efficacy of this type of nature-based beach management is shown at a large scale by comparing vegetated and unvegetated coastal profiles. We argue that preserving and restoring vegetated beach foreshore ecosystems offers a viable, self-sustaining alternative to traditional engineering solutions, increasing the resilience of coastal areas to climate change.
Flood risks are increasing worldwide due to climate change and ongoing economic and demographic development in coastal areas. Salt marshes can function as vegetated foreshores that reduce wave loads on coastal structures such as dikes and dams, thereby mitigating current and future flood risk. This paper aims to quantify long-term (100 years) flood risk reduction by salt marshes. Dike-foreshore configurations are assessed by coupled calculations of wave energy dissipation over the foreshore, sediment accretion under sea level rise, the probability of dike failure, and life-cycle costs. Rising sea levels lead to higher storm waves, and increasing probabilities of dike failure by wave overtopping. This study shows that marsh elevation change due to sediment accretion mitigates the increase in wave height, thereby elongating the lifetime of a dike-foreshore system. Further, different human interventions on foreshores are assessed in this paper: realization of a vegetated foreshore via nourishment, addition of a detached earthen breakwater, addition of an unnaturally high zone, or foreshore build-up by application of brushwood dams that enhance sediment accretion. The performance of these strategies is compared to dike heightening for the physical boundary conditions at an exposed dike along the Dutch Wadden Sea. Cost-effectiveness depends on three main factors. First, wave energy dissipation, which is lower for salt marshes with a natural elevation in the intertidal zone, when compared to foreshores with a high zone or detached breakwater. Second, required costs for construction and maintenance. Continuous maintenance costs and delayed effects on flood risk make sheltering structures less attractive from a flood risk perspective. Third, economic value of the protected area, where foreshores are particularly cost-effective for low economic value. Concluding, life-cycle cost analysis demonstrates that, within certain limits, foreshore construction can be more cost-effective than dike heightening.
Much of the United States’ critical infrastructure is either aging or requires significant repair, leaving U.S. communities and the economy vulnerable. Outdated and dilapidated infrastructure places coastal communities, in particular, at risk from the increasingly frequent and intense coastal storm events and rising sea levels. Therefore, investments in coastal infrastructure are urgently needed to ensure community safety and prosperity; however, these investments should not jeopardize the ecosystems and natural resources that underlie economic wealth and human well-being. Over the past 50 years, efforts have been made to integrate built infrastructure with natural landscape features, often termed “green” infrastructure, in order to sustain and restore valuable ecosystem functions and services. For example, significant advances have been made in implementing green infrastructure approaches for stormwater management, wastewater treatment, and drinking water conservation and delivery. However, the implementation of natural and nature-based infrastructure (NNBI) aimed at flood prevention and coastal erosion protection is lagging. There is an opportunity now, as the U.S. government reacts to the recent, unprecedented flooding and hurricane damage and considers greater infrastructure investments, to incorporate NNBI into coastal infrastructure projects. Doing so will increase resilience and provide critical services to local communities in a cost-effective manner and thereby help to sustain a growing economy.
Floods in India are regular phenomenon that occurs in almost all parts of the country, causing significant damage to human lives, assets and ecosystem. Rapid change in weather patterns and decline in forest cover are considered to be the main reasons for frequent floods and associated damage to both human and natural system. Does forest cover help prevent frequent occurrences of flood and reduce flood related damages? Empirical evidences on the flood protective role of forest cover do not give a clear picture. While few studies find a strong link between forest cover and reduced flood incidence, several other studies from across the globe have challenged this traditional notion of the protective role of forest cover. The present study makes an attempt to examine the association between forest cover and flood damage using data from Indian states and the flood affected districts of the eastern Indian state of West Bengal, taking into account the social, economic, climatic and infrastructural parameters. The findings suggest that forest cover tends to reduce the extent of flood damage and hence has the ability to protect human lives and properties during flood events. It is essential that mitigation and adaptation strategies are shaped in a way that promotes preservation and regeneration of forest resources. Hence, the present study suggests adoption of ecosystem-based adaptation measures along with traditional hard structure flood prevention measures in order to prevent flood related damages effectively.
Intensively used coastal zones often know a history of hard defense structures to prevent erosion and protect infrastructure against floods. The interruption of sand transport between sea, beach and dunes however causes a domination of late successional stages such as dune shrub. With the decline of young, dynamic vegetation types, a change occurs in the provision of ecosystem services. In spite of the growing awareness on the role of dune dynamics to support human well-being and biodiversity, redynamisation of dunes is rarely implemented in coastal zone management. It has been argued in research documents that this may be caused by a failure to make those benefits tangible and specific. This study aims to underpin the added value of dynamic versus fixed dunes. Five different ecosystem services in a case-study in Belgium were quantified based on (compound) indicators and expressed in monetary units. The value of a natural, dynamic dune system covering the entire gradient of dune succession and dominated by young successional stages was compared with the value of a fixed dune system dominated by late successional stages. The results indicate that a dynamic dune complex may create up to ∼50% higher economic benefits, and that the main benefits are on account of recreation and coastal safety maintenance. The results underpin the statement that we can only continue benefitting from the services dunes provide if we accept their mobile nature, but that redynamisation requires a site-specific feasibility analysis.
Planted and invading non-native plant species can alter fire regimes through changes in fuel loads and in the structure and continuity of fuels, potentially modifying the flammability of native plant communities. Such changes are not easily predicted and deserve system-specific studies. In several regions of the southern hemisphere, exotic pines have been extensively planted in native treeless areas for forestry purposes and have subsequently invaded the native environments. However, studies evaluating alterations in flammability caused by pines in Patagonia are scarce. In the forest-steppe ecotone of northwestern Patagonia, we evaluated fine fuels structure and simulated fire behavior in the native shrubby steppe, pine plantations, pine invasions, and mechanically removed invasions to establish the relative ecological vulnerability of these forestry and invasion scenarios to fire. We found that pine plantations and their subsequent invasion in the Patagonian shrubby steppe produced sharp changes in fine fuel amount and its vertical and horizontal continuity. These changes in fuel properties have the potential to affect fire behavior, increasing fire intensity by almost 30 times. Pruning of basal branches in plantations may substantially reduce fire hazard by lowering the probability of fire crowning, and mechanical removal of invasion seems effective in restoring original fuel structure in the native community. The current expansion of pine plantations and subsequent invasions acting synergistically with climate warming and increased human ignitions warrant a highly vulnerable landscape in the near future for northwestern Patagonia if no management actions are undertaken.
New sustainable, cost-effective solutions are urgently needed for river management since conventional practices have posed serious ecological threats on streams, rivers and the surrounding riparian areas. Besides addressing the societal needs e.g. for flood management, river management should increasingly address the ecosystem requirements for improved water quality and biodiversity. We argue that it is not feasible to solve existing and future river management challenges with intensive restoration projects. Instead, we believe that less resource-intensive solutions using natural channel processes and features, including vegetation, should be investigated. Besides directly supporting biota, aquatic and riparian vegetation traps, takes up and helps to process nutrients and harmful substances, and thus this paper emphasizes vegetation as a tool for nature-based solutions (NBS) in river management. We synthesize findings from key literature, showing that the fate of substances in channel systems is largely controlled by abiotic and biotic processes facilitated and modified by vegetation, including flow hydrodynamics, channel morphology, and sediment transport. Subsequently, we demonstrate how vegetation can be incorporated into channel designs, focusing on a two-stage (compound) design to improve resilience to flooding, control the transport of substances, and enhance the ecological status. As a conclusion, clever use and maintenance of vegetation present an unused potential to obtain large-scale positive environmental impacts in rivers and streams experiencing anthropogenic pressures.
Coastal fisheries provide staple food and sources of livelihood in Pacific Island countries, and securing a sustainable supply is recognised as a critical priority for nutrition security. This study sought to better understand the role of fish for Pacific Island communities during disasters and in disaster recovery. To evaluate community impacts and responses after natural disasters, focus group discussions were held with men and women groups at ten sites across Shefa, Tafea, Malampa and Sanma provinces in Vanuatu. The combined impacts of category 5 Tropical Cyclone Pam (TC-Pam) in March 2015 and prolonged El-Niño induced drought have had a profound impact across much of Vanuatu. Terrestrial systems had been disproportionately impacted with substantial shortages in drinking water, garden crops, cash crops and damage to infrastructure. Localized impacts were noted on marine environments from TC-Pam and the drought, along with an earthquake that uplifted reef and destroyed fishing grounds in Malampa province. Communities in Malampa and Shefa provinces also noted a crown-of-thorns outbreak that caused coral mortality. The significant reduction in terrestrial-based food and income generation capacity generally led to increased reliance on marine resources to cope and a shift in diets from local garden food to rice. However, limited market access, lack of fishing skills and technology in many sectors of the community reduced the capacity for marine resources to support recovery. A flexible management approach allowed protected areas and species to be utilized as reservoirs of food and income when temporarily opened to assist recovery. These findings illustrate that fish and fisheries management is at the center of disaster preparedness and relief strategies in remote Pacific Island communities. High physical capital (e.g. infrastructure, water tanks and strong dwellings) is key for disaster preparedness, but supporting community social capital for the purpose of natural resource management and human capital for diverse adaptation skills can also improve community resilience. Recognizing the humanitarian value that well managed fisheries resources and skilled fishers can play to disaster relief adds another dimension to the imperative of improving management of coastal fisheries and aligning policies across sectors.
Ecological infrastructure (EI) refers to ecosystems that deliver services to society, functioning as a nature-based equivalent of, or complement to, built infrastructure. EI is critical for socio-economic development, supporting a suite of development imperatives at local, national and international scales. This paper presents the myriad of ways that EI supports sustainable development, using South Africa and the South African National Development Plan as a case study, linking to the Sustainable Development Goals on a global level. We show the need for EI across numerous development and sustainability issues, including food security, water provision, and poverty alleviation. A strategic and multi-sectoral approach to EI investment is essential for allocating scarce public and private resources for achieving economic and social-ecological priorities. Opportunities to unlock investment in EI, both internationally and on the national level, are identified. This includes leveraging private sector investment into landscape management and integrating the costs of managing EI into public sectors that benefit directly from ecosystem services, such as the water sector and infrastructure development. Additionally, investing in EI also aligns well with international development and climate change funds. Investment in EI from a range of innovative sources supports global and national development, while complementing other development investments.
Background Enhancing water provision services is a common target in forest restoration projects worldwide due to growing concerns over freshwater scarcity. However, whether or not forest cover expansion or restoration can improve water provision services is still unclear and highly disputed. Purpose The goal of this review is to provide a balanced and impartial assessment of the impacts of forest restoration and forest cover expansion on water yields as informed by the scientific literature. Potential sources of bias on the results of papers published are also examined. Data sources English, Spanish and Portuguese peer-review articles in Agricola, CAB Abstracts, ISI Web of Science, JSTOR, Google Scholar, and SciELO. Databases were searched through 2015. Search terms Intervention terms included forest restoration, regeneration/regrowth, forest second-growth, forestation/afforestation, and forestry. Target terms included water yield/quantity, stream-flow, discharge, channel runoff, and annual flow. Study selection and eligibility criteria Articles were pre-selected based on key words in the title, abstract or text. Eligible articles addressed relevant interventions and targets and included quantitative information. Results Most studies reported decreases in water yields following the intervention, while other hydrological benefits have been observed. However, relatively few studies focused specifically on forest restoration, especially with native species, and/or on projects done at large spatial or temporal scales. Information is especially limited for the humid tropics and subtropics. Conclusions and implications of key findings While most studies reported a decrease in water yields, meta-analyses from a sub-set of studies suggest the potential influence of temporal and/or spatial scales on the outcomes of forest cover expansion or restoration projects. Given the many other benefits of forest restoration, improving our understanding of when and why forest restoration can lead to recovery of water yields is crucial to help improve positive outcomes and prevent unintended consequences. Our study identifies the critical types of studies and associated measurements needed.
Resource managers increasingly seek to implement cost-effective-watershed restoration plans for multiple ecosystem service benefits. Using locally adapted ecosystem service tools and historical management costs, we quantified spatially explicit management costs and benefits (in terms of groundwater recharge and landscape flammability) to assist a state agency in evaluating cobenefits for a predefined restoration scenario (focused on biodiversity benefits) and to prioritize an expanded restoration scenario in the state-managed Pu’u Wa’awa’a watershed (Hawai’i) now and under the Representative Concentration Pathway (RCP) 8.5 midcentury climate scenario. Restoring all available -areas increases recharge by similar to 1.74 million m(3)/yr (5% of recharge over the entire watershed) under the current climate and does not meaningfully change recharge under RCP 8.5 midcentury, whereas climate change decreases recharge by similar to 50%. For landscape flammability, climate change increases the median and maximum probability of fire occurrence across all land use scenarios, and full restoration results in the greatest reduction in landscape flammability under both current and RCP 8.5 midcentury climate scenarios. We demonstrate that location and type of forest restoration influence overall cost-effectiveness of – restoration, providing insights for landscape planning for ecosystem services under a limited budget. Across all scenarios, capturing potential benefits at low elevations requires greater expenditures ($13,161/ha) than at high elevations ($5,501/ha) due mainly to the substantial costs of removing Pennisetum setaceum (fountain grass), the dominant land cover below 1,000 m. If management focuses on groundwater recharge only, the most cost-effective areas occur at high elevations (>1,000 m), with ample fog interception, although recharge benefits decline across the landscape under RCP 8.5 midcentury. Focusing instead on cost-effective landscape flammability reduction as the primary management objective shifts emphasis toward dry low-elevation areas under the current climate. However, under the RCP 8.5 midcentury scenario, the most cost-effective areas for flammability management shift toward higher elevations with greater potential overlap with recharge benefits.
Future scenarios indicate that growing human encroachment on coasts, more frequent and stronger storms and sea level rise will result in worsening coastal squeeze. In consequence, human lives, property and infrastructure, as well as ecosystem services, will increasingly be threatened. It is therefore vital to find the means to maintain or increase the resilience and resistance of coastal zones. As an alternative to hard infrastructure, ecosystem-based coastal defense strategies have been recommended as better and more sustainable solutions. Thus, the goal of this study wasto understand the interaction of dune plants with waves, dunes and humans. We used a pantropical beach plant (Ipomoea pes-caprae) and performed 24 wave flume experiments with two beach-dune profiles, four densities of vegetation cover, and three storm regimes. We also tested tolerance to burial in seed germination and seedling growth and finally explored the impact of tourism on Ipomoea. Erosion regimes of collision and overwash were observed in the dune profiles with a berm, whereas swash and overwash regimes were observed when no berm was present. Plant cover prevented overwash and thereby erosion of the landward side of the dune. Positive responses in seeds and seedlings of Ipomoea to burial by sand enable this plant to act as a dune builder. In conditions with low tourism, Ipomoea seems to be more affected by seasonal and meteorological conditions than by trampling. These responses increase further the potential for coastal protection of Ipomoea and, thus, such an ecosystem-based protective structure can be self-sustainable.
Coral reefs can provide significant coastal protection benefits to people and property. Here we show that the annual expected damages from flooding would double, and costs from frequent storms would triple without reefs. For 100-year storm events, flood damages would increase by 91% to $US 272 billion without reefs. The countries with the most to gain from reef management are Indonesia, Philippines, Malaysia, Mexico, and Cuba; annual expected flood savings exceed $400 M for each of these nations. Sea-level rise will increase flood risk, but substantial impacts could happen from reef loss alone without better near-term management. We provide a global, process-based valuation of an ecosystem service across an entire marine biome at (sub)national levels. These spatially explicit benefits inform critical risk and environmental management decisions, and the expected benefits can be directly considered by governments (e.g., national accounts, recovery plans) and businesses (e.g., insurance).
Coastal communities in tropical environments are at increasing risk from both environmental degradation and climate change and require urgent local adaptation action. Evidences show coral reefs play a critical role in wave attenuation but relatively little direct connection has been drawn between these effects and impacts on shorelines. Reefs are rarely assessed for their coastal protection service and thus not managed for their infrastructure benefits, while widespread damage and degradation continues. This paper presents a systematic approach to assess the protective role of coral reefs and to examine solutions based on the reef’s influence on wave propagation patterns. Portions of the shoreline of Grenville Bay, Grenada, have seen acute shoreline erosion and coastal flooding. This paper (i) analyzes the historical changes in the shoreline and the local marine, (ii) assess the role of coral reefs in shoreline positioning through a shoreline equilibrium model first applied to coral reef environments, and (iii) design and begin implementation of a reef-based solution to reduce erosion and flooding. Coastline changes in the bay over the past 6 decades are analyzed from bathymetry and benthic surveys, historical imagery, historical wave and sea level data and modeling of wave dynamics. The analysis shows that, at present, the healthy and well-developed coral reefs system in the southern bay keeps the shoreline in equilibrium and stable, whereas reef degradation in the northern bay is linked with severe coastal erosion. A comparison of wave energy modeling for past bathymetry indicates that degradation of the coral reefs better explains erosion than changes in climate and historical sea level rise. Using this knowledge on how reefs affect the hydrodynamics, a reef restoration solution is designed and studied to ameliorate the coastal erosion and flooding. A characteristic design provides a modular design that can meet specific engineering, ecological and implementation criteria. Four pilot units were implemented in 2015 and are currently being field-tested. This paper presents one of the few existing examples available to date of a reef restoration project designed and engineered to deliver risk reduction benefits. The case study shows how engineering and ecology can work together in community-based adaptation. Our findings are particularly important for Small Island States on the front lines of climate change, who have the most to gain from protecting and managing coral reefs as coastal infrastructure.
This review assesses the degree of resilience of mangroves to large, infrequent disturbance (tsunamis) and their role in coastal protection, and to chronic disturbance events (climate change) and the future of mangroves in the face of global change. From a geological perspective, mangroves come and go at considerable speed with the current distribution of forests a legacy of the Holocene, having undergone almost chronic disturbance as a result of fluctuations in sea-level. Mangroves have demonstrated considerable resilience over timescales commensurate with shoreline evolution. This notion is supported by evidence that soil accretion rates in Mangroves are currently keeping pace with mean sea-level rise. Further support for their resilience comes from patterns of recovery from natural disturbances (storms, hurricanes) which coupled with key life history traits, suggest pioneer-phase characteristics. Stand composition and forest structure are the result of a complex interplay of physiological tolerances and competitive interactions leading to a mosaic of interrupted or arrested succession sequences, in response to physical/chemical gradients and landform changes. The extent to which some or all of these factors come into play depends on the frequency, intensity, size, and duration of the disturbance. Mangroves may in certain circumstances offer limited protection from tsunamis; some models using realistic forest variables suggest significant reduction in tsunami wave flow pressure for forests at least 100 m in width. The magnitude of energy absorption strongly depends on tree density, stem and root diameter, shore slope, bathymetry, spectral characteristics of incident waves, and tidal stage upon entering the forest. The ultimate disturbance, climate change, may lead to a maximum global loss of 10e15% of mangrove forest, but must be considered of secondary importance compared with current average annual rates of 1e2% deforestation. A large reservoir of below-ground nutrients, rapid rates of nutrient flux and microbial decomposition, complex and highly efficient biotic controls, self design and redundancy of keystone species, and numerous feedbacks, all contribute to mangrove resilience to various types of disturbance.
The 2014 Working Group II report of the Intergovernmental Panel on Climate Change (IPCC) warns that low-lying coastal areas are increasingly exposed to risks from sea-level rise, flooding, and extreme storm events (1). Low-lying coasts of developing countries in particular face two types of vulnerability: (i) a lack of capacity to respond quickly and effectively to natural disasters and (ii) declining protection for people and property as coastal habitats disappear. A science-based global strategy for protecting coastal populations should address both sources of vulnerability, through investments in short-run emergency response and long-term coastal adaptation.
Conversion of coastal sand dunes to plantations has intensified dramatically after the tsunami of December 2004, driven largely by the belief that bio-shields mitigated tsunami inundation. This assumption was tested using field-based mapping and remote sensing. A regression between the Normalized Difference Vegetation Index and inundation distance was non-significant, questioning the premise for large-scale bio-shield plantations, mostly Casuarina equisetifolia, an exotic timber with unquantified ecological impacts. These plantations may obliterate the natural sand dune ecosystems along the Coromandel coast, which are an important natural defence and provide a range of ecological goods and services.
Globally, shoreline protection approaches are evolving towards the incorporation of natural and nature-based features (living shorelines henceforth) as a preferred alternative to shoreline armoring. Emerging research suggests that living shorelines may be a viable approach to conserving coastal habitats (marshes, beaches, shallows, seagrasses) along eroding shorelines. Living shorelines typically involve the use of coastal habitats, such as wetlands, that have a natural capacity to stabilize the shore, restore or conserve habitat, and maintain coastal processes. They provide stability while still being dynamic components of the ecosystem, but due to their dynamic nature, careful designs and some maintenance will be required if habitat conservation is a goal. Living shorelines may represent a singular opportunity for habitat conservation in urban and developing estuaries because of their value to society as a shoreline protection approach and resilience to sea level rise. However, enhanced public acceptance and coordination among regulatory and advisory authorities will be essential to expand their use. To fully understand their significance as habitat conservation strategies, systematic and standardized monitoring at both regional and national scales is vital to evaluate the evolution, persistence, and maximum achievable functionality (e.g., ecosystem service provision) of living shoreline habitats.
With the wide acceptance of forest-protection policies in the developing world comes a requirement for clear demonstrations of how deforestation may erode human well-being and economies. For centuries, it has been believed that forests provide protection against flooding. However, such claims have given rise to a heated polemic, and broad-scale quantitative evidence of the possible role of forests in flood protection has not been forthcoming. Using data collected from 1990 to 2000 from 56 developing countries, we show using generalized linear and mixed-effects models contrasted with information-theoretic measures of parsimony that flood frequency is negatively correlated with the amount of remaining natural forest and positively correlated with natural forest area loss (after controlling for rainfall, slope and degraded landscape area). The most parsimonious models accounted for over 65 % of the variation in flood frequency, of which nearly 14 % was due to forest cover variables alone. During the decade investigated, nearly 100,000 people were killed and 320 million people were displaced by floods, with total reported economic damages exceeding US$1151 billion. Extracted measures of flood severity (flood duration, people killed and displaced, and total damage) showed some weaker, albeit detectable correlations to natural forest cover and loss. Based on an arbitrary decrease in natural forest area of 10 %, the model-averaged prediction of flood frequency increased between 4 and 28 % among the countries modeled. Using the same hypothetical decline in natural forest area resulted in a 4 – 8 % increase in total flood duration. These correlations suggest that global-scale patterns in mean forest trends across countries are meaningful with respect to flood dynamics. Unabated loss of forests may increase or exacerbate the number of flood-related disasters, negatively impact millions of poor people, and inflict trillions of dollars in damage in disadvantaged economies over the coming decades. This first global-scale empirical demonstration that forests are correlated with flood risk and severity in developing countries reinforces the imperative for large-scale forest protection to protect human welfare, and suggests that reforestation may help to reduce the frequency and severity of flood-related catastrophes.
The main objective of this paper is to combine and integrate environmental, economic and social impact assessment procedures in order to support decision-making in the context of flood control policy in the Netherlands. The hydraulic, hydrological, ecological, economic and social effects of alternative flood control policies, such as land use change and floodplain restoration, are evaluated using a combination of advanced quantitative modelling techniques and qualitative expert judgement. The results from the ecological, economic and social impact assessment are evaluated in an integrated way through cost – benefit analysis (CBA) and multi-criteria analysis (MCA). As expected, these methods produce different outcomes. Although traditional flood control policy-building higher and stronger dikes-is a cost-effective option, investment in alternative flood control policy-land use changes and floodplain restoration-can be justified on the basis of both CBA and MCA when including the additional ecological and socio-economic benefits in the long run. The outcome of the MCA appears to be especially sensitive to the inclusion of the qualitative scores for the expected social impacts of land use change and floodplain restoration. An important research question remains how to assess, integrate and trade-off (1) significantly different types of impacts in a methodologically sound way in both cost – benefit and multi-criteria analysis, and (2) significantly different types and quality of available knowledge and information about these impacts.
Flooding is a very costly natural hazard in the UK and is expected to increase further under future climate change scenarios. Flood defences are commonly deployed to protect communities and property from flooding, but in recent years flood management policy has looked towards solutions that seek to mitigate flood risk at flood-prone sites through targeted interventions throughout the catchment, sometimes using techniques which involve working with natural processes. This paper describes a project to provide a succinct summary of the natural science evidence base concerning the effectiveness of catchment-based ‘natural’ flood management in the UK. The evidence summary is designed to be read by an informed but not technically specialist audience. Each evidence statement is placed into one of four categories describing the nature of the underlying information. The evidence summary forms the appendix to this paper and an annotated bibliography is provided in the electronic supplementary material.
Protection against coastal disasters has been identified as an important service of mangrove ecosystems. Empirical studies on this service have been criticized, however, for using small samples and inadequately controlling for confounding factors. We used data on several hundred villages to test the impact of mangroves on human deaths during a 1999 super cyclone that struck Orissa, India. We found that villages with wider mangroves between them and the coast experienced significantly fewer deaths than ones with narrower or no mangroves. This finding was robust to the inclusion of a wide range of other variables to our statistical model, including controls for the historical extent of mangroves. Although mangroves evidently saved fewer lives than an early warning issued by the government, the retention of remaining mangroves in Orissa is economically justified even without considering the many benefits they provide to human society besides storm-protection services.
CSIR-National Environmental Engineering Research Institute (CSIR-NEERI) along with the United Nations Environment Programme (UNEP), Geneva, organized a consultative workshop on “Ecological Engineering for DRR (Disaster Risk Reduction) and CCA (Climate Change Adaptation)” in NEERI, Nagpur, on February 5, 2016. The workshop brought together technical experts and policy makers across India to review how the new opportunities offered by science and international policies could be leveraged to promote ecosystem-based (Eb) approaches in India. The consultation succeeded in brainstorming and identifying key actions, actors, and priority areas keeping in view conservation and development challenges. Discussions were also on implementation strategies, monitoring and evaluation mechanisms. Workshop also came up with integrating biodiversity management with existing and ongoing development practices, including existing policy measures and enabling mechanisms at regional, national, and state level. Priority actions for improving DRR approaches, and identification of interventions to support EbDRR and EbA in the country, and possible role and responsibility of potential national institutions and other agencies were the final outcomes of the brainstorming and workshop.
“Ecological Infrastructure (EI)” are defined as naturally functioning ecosystems that deliver valuable services to people, such as healthy mountain catchments, rivers, wetlands, coastal dunes, and nodes and corridors of natural habitat, which together form a network of interconnected structural elements in the landscape. On the other hand, natural disaster occur at the locations where habitat was reduced due to the changes of land use, in which the land was converted to the settlements and agricultural cropland. Hence, habitat loss and natural disaster are linked closely. Ecological infrastructure is the nature-based equivalent of built or hard infrastructure, and is as important for providing services and underpinning socio-economic development. Hence, ecological infrastructure is expected to contribute to functioning as ecological disaster reduction, which is termed Ecosystem-based Solutions for Disaster Risk Reduction (Eco-DRR). Although ecological infrastructure already exists in the landscape, it might be degraded, needs to be maintained and managed, and in some cases restored. Maintenance and restoration of ecological infrastructure is important for security of human lives. Therefore, analytical tool and effective visualization tool in spatially explicit way for the past natural disaster and future prediction of natural disaster in relation to ecological infrastructure is considered helpful. Hence, Web-GIS based Ecological Infrastructure Environmental Information System (EI-EIS) has been developed. This paper aims to describe the procedure of development and future application of EI-EIS. The purpose of the EI-EIS is to evaluate functions of Eco-DRR. In order to analyse disaster data, collection of past disaster information, and disaster-prone area is effective. First, a number of digital maps and analogue maps in Japan and Europe were collected. In total, 18,572 maps over 100 years were collected. The Japanese data includes Future-Pop Data Series (1,736 maps), JMC dataset 50m grid (elevation) (13,071 maps), Old Edition Maps: Topographic Map (325 maps), Digital Base Map at a scale of 2500 for reconstruction planning (808 maps), Detailed Digital Land Use Information for Metropolitan Area (10 m land use) (2,436 maps), and Digital Information by GSI (national large scale map) (71 maps). Old Edition Maps: Topographic Map were analogue maps, and were scanned and georeferenced. These geographical area covered 1) Tohoku area, 2) Five Lakes of Mikata area (Fukui), 3) Ooshima Island (Tokyo), 4) Hiroshima area (Hiroshima), 5) Okushiri Island (Hokkaido), and 6) Toyooka City area (Hyogo). The European data includes topographic map in Germany (8 maps), old topographic map in Germany (31 maps), ancient map in Germany (23 maps), topographic map in Austria (9 maps), old topographic map in Austria (17 maps), and ancient map in Austria (37 maps). Second, focusing on Five Lakes of Mikata area as an example, these maps were integrated into the ArcGIS Online (R) (ESRI). These data can be overlaid, and time-series data can be visualized by a time slider function of ArcGIS Online.