Ecosystem-based Disaster Risk Reduction Research Articles

Does willingness to pay for the traditional flood control measures kasumitei vary by river section of residential area?

Kasumitei (open levees) comprise a traditional flood mitigation measure used in Japan. Kasumitei allow floodwater to flow into surrounding paddy fields, which act as temporary flood mitigation basins. After flooding, debris accumulated in paddy fields often brings crop damage and debris removal costs. Therefore, in some areas, the disaster mitigation functions of kasumitei may bring about conflicts between beneficiaries (downstream residents) and burden bearers (midstream residents). Ensuring the continued use of kasumitei in the future requires a mechanism to support the burden bearers. This study aimed to test the hypothesis that the willingness to pay (WTP) for maintaining the kasumitei would be lower for midstream residents (potential burden bearers) than for upstream (irrelevant) and downstream residents (potential beneficiaries). The results showed that contrary to the hypothesis, WTP for maintaining kasumitei was not affected by the river sections of the respondents' residence. Thus, a financial support scheme for maintaining kasumitei might be acceptable regardless of the beneficiary or bearer in the surveyed respondents. In addition, respondents with higher interest in ecosystem conservation tended to have higher WTP. Therefore, to gain support for the maintenance and use of the kasumitei (a type of ecosystem-based disaster risk reduction), the authorities would promote awareness of the measure's contribution to ecosystem conservation. Based on the results, we discussed the potential financial support schemes for maintaining the kasumitei.

Small-Scale Experimental Evidence On The Use Of Date Palm Forest To Mitigate Tsunami In The Arabian Sea

Because of the multi-scale benefits, ecosystem-based disaster risk reduction (Eco-DRR) has received much attention in coastal disaster mitigation. Coastal forests are considered a sustainable and economical solution to mitigate inundations from tsunamis. Owing to the rare occurrence of tsunamis and reported local tsunami heights being small, the coastal forests are a potential solution to protect from tsunamis in the Arabian Sea. The potential of date palm trees to mitigate tsunami inundations was investigated in an experimental study. The experiments were conducted at a geometric scale of 1:100 with the Froude-Cauchy similitudes. It found that the canopy of the tree played a key role in flow energy reduction. If the tsunami height was higher than the canopy height a significant tsunami depth was reduced behind the forest compared to the case that the tsunami height was lower than the canopy height. The highest percentage reduction in the maximum flow depth behind the forest was 37% for the forest length of 180 m and tsunami height of 7 m.

Valuing hybrid engineering approach: ecosystem and structural based DRR using InVEST model of coastal zone Sikka Flores-Literature Review

The effectiveness and long-term viability of implementing eco-DRR are heavily influenced by the regional context, including factors such as geographical locations, circumstances, and features of risks. The implementation of eco-DRR measures in coastal areas is effectively mitigating the hazards posed by high waves and other hydro-meteorological events, including storm surges, erosion, and coastal floods. The study was carried out within the framework of mangrove forest development as a means of combined protection and hard structural intervention. The success and efficacy of this endeavor rely on various circumstances, such as the magnitude of the large waves and the characteristics of the nearshore bathymetry, which dictate the extent to which the waves reach the coastline beach. In order to achieve optimal effectiveness and provide prompt safeguarding, it is necessary to employ a hybrid approach that combines ecosystem-based disaster risk reduction (DRR) methods with physical structures. This is because non-structural measures, such as ecosystems, inherently require time to grow and are highly susceptible to destruction from waves, rock debris, and water currents. Nevertheless, the ’hybrid approach’ or amalgamation must be formulated in a manner that does not engender novel or distinct dangers in various areas. This study seeks to conduct a comparative analysis of studies on Eco-DRR (Ecological Disaster Risk Reduction) focusing on high waves and other hydrometeorological risks in coastal areas. The objective is to develop a hybrid model that combines Eco-DRR and engineering effectiveness evaluation for disaster risk management, specifically for the Sikka Flores coastline area.

The potential for community-driven ecosystem-based disaster risk reduction in South Asia: a literature review

PurposeThe paper reviews existing literature on South Asian ecosystem-based disaster risk reduction (DRR) and identifies how community participation can be used to plan and implement ecosystem-based DRR approaches.Design/methodology/approachThe literature review methodology involved several stages. Firstly, the research objective was determined. Secondly keywords for the literature search were determined. Scopus, Google Scholar, JSTOR and AUT online library were utilized for the literature search. After the search, the literature was screened. The study design, methodology, results and limitations were identified and documented. After data extraction, the literature was analyzed. The patterns, trends and inconsistencies in the literature were identified based on the research question. Later the gaps, controversies and future research needs were identified. Then, a comprehensive and structured literature review that summarizes the relevant literature, synthesizes the findings and provides a critical evaluation of the literature was documented. After writing the document, it was reviewed and edited to ensure its clarity, accuracy and coherence.FindingsThe paper identifies four different themes recurrently emerging in literature on the importance of community participation in ecosystem-based DRR in South Asia. The themes are local community participation in ecosystem-based DRR governance, knowledge production, livelihood enhancement and increased public acceptance.Originality/valueThe paper also illustrates the challenges in integrating community participation with the dominant physical scientific approaches ecosystem-based DRR and proposes a five-element framework to facilitate the integration.

Integrated Disaster Risk Management in the Education Process in Schools

Research in educational disaster mitigation has developed and is widely carried out, especially in schools. This research explores good practices based on the experience of teachers in Indonesia regarding the possibility of integrating DRR (Disaster Risk Reduction) education into the learning process in schools. This study used research and development (R and D) methods with the APPED model (preliminary analysis and research, design, production, evaluation and dissemination), which was carried out for two years. In particular, this paper reports the results of the first year’s research with research activities including: (i) analysis and preliminary research and (ii) design. In the initial analysis and research stages, the research team carried out several activities, including analysis of material coverage, learning outcomes, and learning activities through literature review and document analysis, combined with case studies and FGD (Focus Group Discussion) involving 87 teachers in Yogyakarta, Malang, and Ciamis. Furthermore, the results of the activities in the second stage, (Design), are in the form of an analysis of the needs of students in DRR (Disaster Risk Reduction) education based on Ecosystem-based Disaster Risk Reduction (Eco-DRR). Studies reveal that DRR (Disaster Risk Reduction) education has the potential to be integrated into educational activities in schools. Practically, the main components of DRR (Disaster Risk Reduction) education include: coverage of materials, learning outcomes, and learning activities. The research results also show that the integrated interdisciplinary curriculum model has the potential to be adopted in the implementation of DRR (Disaster Risk Reduction) education, through intra-curricular, extra-curricular and co-curricular learning activities. This finding has implications for the need for teacher involvement in the next research stage, where production, evaluation, and dissemination processes are carried out. Good practices that have been carried out by teachers have become one of the important instruments in implementing integrated disaster risk management with the educational process in schools . Further, important to consider the integration of science and indigenous knowledge (ISIK) in implementing DRR education in schools, through intra-curricular, extra-curricular and co-curricular. The disaster and mitigation knowledge were empirical, genuine, participatory and interactive, within the localities context. Schools can be good agents for dissemination of the ISIK perspective in disaster and mitigation studies. Although the relation between scientific and indigenous knowledge is proposed by the participants, but theoretically and practically needed follow-up studies, especially to reduce the level of vulnerability.

Moving towards a comprehensive evaluation of ecosystem-based disaster risk reduction: The example of agroforestry for flood risk reduction

Nature-based solutions (NbS) have received increased interest as cost-effective contributors to addressing societal challenges, with ecosystem-based disaster risk reduction (Eco-DRR) being the specific approach for reducing disaster risk under the NbS umbrella. Ecosystem services (ES) provided by Eco-DRR measures are known to contribute to reducing all three components of disaster risk. Yet, Eco-DRR evaluation falls short of recognising this, and this hampers its strategic placement and effective use. This paper addresses the challenge of evaluating the impact of Eco-DRR measures on reducing hazard, exposure and vulnerability. The methodological approach for Eco-DRR evaluation is developed for agroforestry as an example of ecosystem-based measure for flood risk reduction. The literature review on ES provided by cropland versus agroforestry provided the basis to elaborate on how the quantitative evaluation of such a measure for flood risk reduction could be realised in a next step. An additional literature review served to create a look-up table on the effects of agroforestry on hydrological processes in comparison to cropland. This can serve as input for re-running the hydrological model and comparing the hazard before and after the agroforestry implementation. The paper also captures the effects of agroforestry implementation on social and ecological vulnerability through changes in ES provision. Changes in ES provision resulting from the implementation of an agroforestry measure on cropland were related to social and ecological vulnerability using a deductive approach. The concept for comprehensive evaluation developed in this paper provides the groundwork for evaluating the risk reduction potential of Eco-DRR with reference to a tailored risk assessment.

A Resilience Enhancement Approach to the Sponge City Based on Ecosystem-Based Disaster Risk Reduction—Taking the Urban Design of Jiangchuanlu Street in Shanghai, China as an Example

A Resilience Enhancement Approach to the Sponge City Based on Ecosystem-Based Disaster Risk Reduction—Taking the Urban Design of Jiangchuanlu Street in Shanghai, China as an Example

Three-dimensional analyses of China's marine disaster management policies (1990–2022): With implications for carbon neutrality

To address challenges associated with climate change, the concept of carbon neutrality has been proposed and explored worldwide. In this context, coastal blue carbon, recognized as one of the most effective carbon sinks, is regrettably highly susceptible to marine disasters. With this in mind, the present study scrutinized China's Marine Disaster Prevention and Mitigation (MDPM) policies (1990–2022) to complement its carbon neutrality strategy. Specifically, we developed a three-dimensional framework to systematically examine China's evolving MDPM policy landscape, considering administrative institutions, policy emphases, and policy instruments. To accomplish this, we integrated network analysis, word cloud analysis, and coding-based content analyses. We discerned that the interdepartmental collaboration in China's MDPM has augmented over time, signaling a transition towards integrated marine disaster management. Additionally, there were notable transformations in the policy emphases and policy instruments of China's MDPM at different periods, indicating the adaptive nature of its MDPM policies. However, rehabilitation and reconstruction have persistently received minimal policy attention, and the command-and-control approach has continued to be the predominant policy instrument. Our insights illuminate new avenues for advancing China's carbon neutrality, such as by synchronizing coastal blue carbon conservation with MDPM initiatives, adopting ecosystem-based disaster risk reduction methods, advocating for holistic management of the entire disaster process, involving societal participants, and by amplifying scientific and technological support coupled with boosting information transparency.

Assessment of Ecosystem-Based Disaster Risk Reduction Strategies in Coastal Environments of Taiwan

Taiwan’s rapid economic and industrial growth has put enormous pressure on its natural environment. This is especially visible in the coastal zone, where risks such as sea-level rise, coastal erosion, land subsidence, and flooding threaten the already vulnerable ecosystems. Ecosystem-based disaster risk reduction (Eco-DRR) is a management strategy that uses ecosystems to reduce disaster risks. While this type of strategy is promoted in the ‘Taiwan Coastal Zone Management Act’ (TCZMA), there is still a lack of data on the implementation of Eco-DRR methods in Taiwan. This study examines papers on policy analyses of the TCZMA, and five main barriers for implementation of Eco-DRR in Taiwan are identified. Subsequently, in order to assess Eco-DRR strategies in the coastal zone of Taiwan, case studies and evaluation data on ecosystem-based management strategies were assembled and evaluated. The results of this study show that initial strategies to plant mangroves for reduction of wave energy have not always been successful; in certain areas they were removed again due to invasiveness in endemic wetland ecosystems. Moreover, artificially building sand dunes can have negative side effects, like oversteepening of the dune profile or deteriorating the natural dune dynamics. To address and tackle aforementioned challenges, a novel framework is introduced for improved uptake of Eco-DRR in Taiwan and beyond, and suggestions for future strategies are proposed.

Special Issue on ICoE Taipei Integrated Research on Disaster Risk

Established in 2010 as an integrated research program for disaster risk reduction, the IRDR ICoE Taipei is co-sponsored by the International Science Council (ISC) and the United Nations Office for Disaster Risk Reduction (UNDRR). In the past decade, the IRDR ICoE Taipei has received hundreds of participants around the world to the more than a dozen international training workshops (AI, Advanced Institute) it has organized. These workshops focused mostly on the capacity building program for disaster risk reduction. Bearing this in mind, one important motivation for this Special Issue was to encourage the participants of each Advanced Institute, in particular those who were awarded Seed Grants to conduct one-year projects following each workshop, to publish the results of their studies on the topics related to disaster risk reduction. In this Special Issue, the first paper provides a brief review of the capacity building program of the IRDR ICoE Taipei, followed by three research articles. Viola van Onselen and her co-workers in Taiwan present a methodology of strategies of ecosystem-based disaster risk reduction, with several case studies in coastal environments of Taiwan. Shyamli Singh of India proposes an integrated system for sustainable rice economics linking from farm to market, a case study on one of the largest rice production fields on the Indo-Gangetic plain. From the engineering perspective, Wen-Yi Huang and his colleagues in Taiwan and Australia present a paper dealing with the reinforcement of soil walls to prevent geohazards on the roads. This is the first special issue produced as a collaboration between the IRDR ICoE Taipei and the JDR, with great support from the National Science and Technology Center for Disaster Reduction (NCDR) and Academia Sinica of Taiwan. We hope there will be more Special Issues to come in the next few years.

Impact of Vegetation Differences on Shallow Landslides: A Case Study in Aso, Japan

Climate change has increased the frequency and scale of heavy rainfall, increasing the risk of shallow landslides due to heavy rainfall. In recent years, ecosystem-based disaster risk reduction (Eco-DRR) has attracted attention as one way to reduce disaster risks. Vegetation is known to increase soil strength through its root system and reduce the risk of shallow landslides. To reduce the risk of shallow landslides using vegetation, it is necessary to quantitatively evaluate the effects that vegetation has on shallow landslides. In this study, we constructed a generalized linear model (GLM) and random forest (RF) model to quantitatively evaluate the impact of differences in the vegetation, such as grasslands and forests, on the occurrence of shallow landslides using statistical methods. The model that resulted in the lowest AIC in the GLM included elevation, slope angle, slope aspect, undulation, TWI, geology, and vegetation as primary factors, and the hourly rainfall as a trigger factor. The slope angle, undulation, and hourly rainfall were selected as significant explanatory variables that contribute positively to shallow landslides. On the other hand, elevation and TWI were selected as significant explanatory variables that contribute negatively to shallow landslides. Significant differences were observed among multiple categories of vegetation. The probability of shallow landslide in secondary grasslands was approximately three times that of coniferous and broadleaf forests, and approximately nine times that of broadleaf secondary forests. The landslide probability of shrubs was approximately four times that of coniferous and broadleaf forests, and approximately ten times that of broadleaf secondary forests. The results of constructing the RF model showed that the importance was highest for the hourly rainfall, followed by geology, then elevation. AUC values for the GLM and RF model were 0.91 and 0.95, respectively, indicating that highly accurate models were constructed. We quantitatively showed the impact of differences in vegetation on shallow landslides. The knowledge obtained in this study will be essential for considering appropriate vegetation management to reduce the risk of future shallow landslides.

Analysis of Community Adaptation Strategies Factors for Ecosystem-Based Disaster Risk Reduction in the Upper Merawu Watershed

The Merawu Watershed is one of the critical watersheds in Indonesia. This watershed is located in Banjarnegara Regency which has an altitude of 1000 meters above sea level with high rainfall intensity. The type of soil in Banjarnegara Regency is mostly ultisol and inceptisol soil, making the area vulnerable to landslides. Under these conditions, intensive agriculture is mostly carried out by the surrounding community, with the main commodity being planted is potatoes. Planting without paying attention to soil and water conservation techniques on steep land and spraying pesticides with high intensity can trigger erosion, landslides, and environmental pollution. The hamlets of Tamansari and Penanggungan are prone to erosion, landslides, and environmental pollution due to intensive agriculture. But, the adaptation strategy adopted by the community is still lacking. Therefore, it is necessary to research the factors that influence community adaptation strategies in ecosystem-based disaster risk reduction. This study aims to identify the factors that influence the adaptation strategy. The method used in this research is the logit model method. The respondents used in this study were 30 from the Tamansari Hamlet and the Penanggungan Hamlet. The results showed that the adaptation strategies factors for erosion are land area and household income, while landslides are assets and location. There are no variables that have a significant effect on the community's adaptation strategy to environmental pollution.

Waterline digital elevation model development to quantify inundation duration and coastal protection of tidal wetlands

Coastal tidal wetlands are sufficiently acknowledged for the supplied vital ecosystem functions, including flood protection and biological conservation. Measuring and estimating reliable topographic data is essential for quantifying mangrove habitat quality. This study proposes a novel methodology for quickly constructing a digital elevation model (DEM) with an instantaneous waterline combined with tidal level records. Unmanned aerial vehicles (UAVs) enabled on-site waterline interpretation analysis. The results show that image enhancement improves the accuracy of waterline recognition and object-based image analysis has the highest accuracy. The waterline DEM (WDEM) performs a more accurate elevation production than UAV DEM, indicating that its application to habitat evaluation and prediction could be more reliable. Hydrodynamic simulations incorporated with the mangrove habitat model were utilized to calculate inundation duration, flow resistance, and vegetation dissipation potential according to the verified WDEM. The larger the mangrove coverage ratio, the stronger the flow resistance, which means that the protective consequence of the mangrove on the natural embankment is evident. The WDEM and nature-based solutions presented facilitate an adequate understanding of coastal protection and promote the potential ecosystem-based disaster risk reduction of mangrove wetlands.

Ecosystem-Based Disaster Management Planning for the Eastern Coast of India

Elango, N. and Arul, C., 2023. Ecosystem-based disaster management planning for the eastern coast of India. Journal of Coastal Research, 39(1), 83–89. Charlotte (North Carolina), ISSN 0749-0208. The coastal zone of India is endowed with abundant coastal and marine ecosystems. India is also highly prone to natural calamities, especially floods, droughts, cyclones, and landslides. This study aims to highlight the importance of the ecosystem services along the east coast of India and incorporate the value of these resources at the planning stage of disaster management at all levels. A survey was conducted with experts at the national level who have an understanding of the existing disaster management plans along the coast of Tamil Nadu state. To understand the importance of ecosystem-based disaster risk reduction at the decision-making and planning level, further analysis was carried out in monetization of ecosystem services. The total value of ecosystem services was obtained as the product of landuse area and the value of ecosystem services. From the overall critical analysis and the initial online survey, it was inferred that ecosystem-based approaches to disaster risk reduction and managing climate change hold much promise and that investing in healthy ecosystems provides a viable route for sustainable development. There needs to be a shift from relying on structural engineering solutions to increased acceptance of social engineering approaches through consensus-building with disaster-affected communities. Despite the structural and nonstructural measures being implemented in lieu of disaster management, there is still a lacuna in effective implementation, as inferred from the study. Robust actions are needed at the planning stage, for which the adoption of ecosystem-based approaches with localised resources and knowledge would be an inclusive approach.

Evaluating the effectiveness of basin management using agricultural land for ecosystem-based disaster risk reduction

Flood risk reduction is a crucial global issue. Structural measures against floods have an upper limit on their function; thus, when the magnitude of floods exceeds this upper limit, few functions can prevent damage. Non-structural measures such as ecosystem-based strategies for disaster risk reduction (Eco-DRR) are attracting growing interest. In this study, I test the effectiveness of flood mitigation on agricultural land, which is a semi-natural ecosystem, using both municipality and watershed data from 9 years of statistical records on flood damage to test the relationship between flood frequency and land use patterns with terrain conditions in both municipalities and watersheds. I also conduct a simulation in which agricultural land use is reduced to compare the effectiveness of flood mitigation between the two scales. The results indicate that both paddy fields and dry farmland located in a water storage zone are effective in reducing flood frequency. In addition, this function is greater for watersheds than for municipalities. Thus, the conservation of agricultural land in which water storage zones are located could enhance Eco-DRR for flooding, especially in watersheds. I conclude that combining structural and non-structural measures—namely, Eco-DRR—is the most effective flood mitigation strategy for watersheds.

Mainstreaming Ecosystem-Based Disaster Risk Reduction: Towards a Sustainable and Just Transition in Local Development Planning in Rural South Africa

Ecosystem-based disaster risk reduction (Eco-DRR) is gaining momentum globally and is also considered to enhance climate change adaptation and sustainable transition to a low-carbon economy in South Africa. However, there is little evidence regarding how the approach is applied at the local level. It also remains unclear to what extent the approach is integrated into local development planning and what opportunities exist for further integration in rural areas. Therefore, our study examined opportunities for mainstreaming Eco-DRR into local development planning in South Africa. Fourteen integrated development plans from ‘mostly rural’ local municipalities in Limpopo Province were systematically assessed to understand the process of mainstreaming Eco-DRR into their current development plans under the following aspects: localized climate trends, hydroclimatic risks considered, risk and vulnerability assessments, disaster risk reduction (DRR) actions, early-warning systems, financing mechanisms, integration of traditional and technical knowledge, stakeholder engagement, and alignment with district, provincial, and national priorities. Although all plans address DRR, none explicitly addresses Eco-DRR, despite a few similar actions. DRR actions are not aligned to any hydroclimatic risks, and most plans lack localized climate trends and/or vulnerability assessments to indicate the severity of hazards and/or identify populations and areas at risk. Several measures in the plans address disaster preparedness, but none includes early-warning systems. Public participation features prominently in all plans, but the process is marred by challenges and lacks genuineness, e.g., prioritized actions are not reflective of community needs. Based on the findings, we discuss measures to enhance the mainstreaming of ecosystem-based approaches into DRR. We conclude that a huge opportunity exists to institutionalize and mainstream Eco-DRR into local development planning in South Africa’s rural areas. If carefully seized, such an opportunity can also help attract external finance to complement the currently constrained budgets related to addressing hydroclimatic risks.

Ecosystem-based disaster risk reduction can benefit biodiversity conservation in a Japanese agricultural landscape

Ecosystem-based disaster risk reduction (Eco-DRR) has attracted increased attention as a sustainable way to achieve both disaster risk reduction and biodiversity conservation, although there have been few quantitative evaluations of the potential impacts of Eco-DRR on biodiversity. Here, we examined the influences of flood hazard and land-use patterns on biodiversity by focusing on the species richness of plants, butterflies and odonates, and the abundance of two frog species in a rural landscape of Wakasa town, Fukui Prefecture, Japan. The direct effect of exposure to flood hazard on the studied taxa was not significant, whereas landscape factors associated with flood hazard significantly influenced either of the taxa in different magnitudes. We then exercised a scenario analysis by replacing urban land-use by non-urban, agricultural land-use (paddy fields in this case) to reduce exposure to flood hazard and projected the impacts on biodiversity. Our results demonstrated that the land-use replacement potentially reduces the risk of flooding by up to 5.19 billion yen (ca. 46 million US$) and, at the same time, positively influences the species richness and abundance, although the ecological impacts are different depending on taxon and spatial location. The land-use replacement was expected to result in the increase of plant richness and abundance of Daruma pond frog at a location by up to 16 and 25%, respectively. On the other hand, butterfly richness at a location was presumed to decrease by until −68%, probably due to their dependence on domestic gardens. The abundance of Japanese wrinkled frog did not show such a clear spatial variation. This study highlights the significance of land-use replacement as an Eco-DRR measure to reduce the disaster risk and conserve biodiversity in the agricultural landscape.

Application of the protective action decision model in land-use scenario analysis for disaster risk reduction

Land-Change Science is an emergent field that seeks to enhance understanding of the negative impacts of land use and cover change (LUCC) in order to expedite the development of sustainable resource management and sustainable land use policies. Dr Kikuko Shoyama is a research fellow at the National Research Institute for Earth Science and Disaster Resilience, Japan, who is conducting research on Land-Use Functions. In her latest project, she is focusing on ecosystem-based disaster risk reduction (Eco-DRR) and she and the team will explore how to utilise Eco-DRR as one of the Land-Use Functions and look at the type of payment system that is needed to support community activities. This work on designing so-called payment for ecosystem services (PES) involves recognising and valuing the variety of services that ecosystems provide to society. Through PES, an awareness and appreciation of the value of ecosystems can be cultivated. In her work on Eco-DRR, Shoyama is investigating the effects of land use policies on disaster reduction, with a focus on flood risk information and the impact of policies that promote or inhibit protective behaviour related to land use. The work involves the use of a hierarchical linear model that extracts the factors affecting protective behaviours by taking into account land ownership and community characteristics. The factors can then be introduced into a land use model and analyses are performed. Ultimately, Shoyama hopes her work will lead to recommendations that will inform a newer land use strategy and social transformative change.

Evaluation of Pandanus Trees as a Means of Eco-DRR against Storm Surge Wave on Saint Martin’s Island, Bangladesh

Saint Martin’s Island is a tiny island located in Bangladesh that is rich in biodiversity but threatened by many natural disasters, and it is often neglected due to being far from the mainland. Ecosystem-based disaster risk reduction (Eco-DRR) is the most urgently required provision for Bangladesh as it is a very easy and inexpensive way to survive natural adversities. In this study, attempts were made to quantify the capacity of an existing Pandanus forest on Saint Martin’s Island to reduce the storm surge disaster risk. For this, satellite images were processed with ErdasImagine and ArcGIS software, and land use and land cover changes were analyzed to determine the changes related to Pandanus trees over time. Storm surge wave height reduction was analyzed using the Bao regression model equation. The results show that the Pandanus tree population increased almost 3-fold from 2010 to 2021, and that the Pandanus trees can reduce the surge height, which will ultimately preserve 75% of the area of the island (2021). The minimum required patch width for the Pandanus tree belt was identified as 4.53 m. The areas highly vulnerable to flooding were also identified in this study.

Enhancing disaster risk resilience using greenspace in urbanising Quito, Ecuador

Abstract. Greenspaces within broader ecosystem-based disaster risk reduction (Eco-DRR) strategies provide multiple benefits to society, biodiversity, and addressing climate breakdown. In this study, we investigated urban growth, its intersection with hazards, and the availability of greenspace for disaster risk reduction (DRR) in the city of Quito, Ecuador, which experiences multiple hazards including landslides, floods, volcanoes, and earthquakes. We used satellite data to quantify urban sprawl and developed a workflow incorporating high-resolution digital elevation models (DEMs) to identify potential greenspaces for emergency refuge accommodation (DRR greenspace), for example, following an earthquake. Quito's historical urban growth totalled ∼ 192 km2 for 1986–2020 and was primarily on flatter land, in some cases crossed by steep ravines. By contrast, future projections indicate an increasing intersection between easterly urbanisation and steep areas of high landslide susceptibility. Therefore, a timely opportunity exists for future risk-informed planning. Our workflow identified 18.6 km2 of DRR greenspaces, of which 16.3 km2 intersected with potential sources of landslide and flood hazards, indicating that hazard events could impact potential “safe spaces”. These spaces could mitigate future risk if designated as greenspaces and left undeveloped. DRR greenspace overlapped 7 % (2.5 km2) with municipality-designated greenspace. Similarly, 10 % (1.7 km2) of municipality-designated “safe space” for use following an earthquake was classified as potentially DRR suitable in our analysis. For emergency refuge, currently designated greenspaces could accommodate ∼ 2 %–14 % (depending on space requirements) of Quito's population within 800 m. This increases to 8 %–40 % considering all the potential DRR greenspace mapped in this study. Therefore, a gap exists between the provision of DRR and designated greenspace. Within Quito, we found a disparity between access to greenspaces across socio-economic groups, with lower income groups having less access and further to travel to designated greenspaces. Notably, the accessibility of greenspaces was high overall with 98 % (2.3 million) of Quito's population within 800 m of a designated greenspace, of which 88 % (2.1 million) had access to potential DRR greenspaces. Our workflow demonstrates a citywide evaluation of DRR greenspace potential and provides the foundation upon which to evaluate these spaces with local stakeholders. Promoting equitable access to greenspaces, communicating their multiple benefits, and considering their use to restrict propagating development into hazardous areas are key themes that emerge for further investigation.