Nature-based Solutions Research Articles

Two decades of land cover change and anthropogenic pressure around Bontioli Nature Reserve in Burkina Faso

Protected areas (PAs) are critical for ecosystem maintenance and providing services that benefit both wildlife and people. Nevertheless, climate change and anthropogenic pressures are posing an increasing challenge. Surrounded by high human population densities, there is still a paucity of information on how the land cover in Burkina Faso's PAs is changing, and what kinds of human activities are the main drivers. In this study, we examined the change in land use and land cover (LULC) in the Bontioli Nature Reserve (NR), one of Burkina Faso's most important protected areas, and assessed anthropogenic pressure within and around. Landsat imagery (ETM+ and OLI-TIRS) is used to categorise and estimate the change in LULC in 2000, 2010, and 2022 with the Random Forest algorithm on the Google Earth Engine platform. Regression analysis was applied to examine the relationship between the LULC categories and population increase. We found significant changes and correlations in LULC trends and population growth over time. From 2000 to 2022, wooded savanna, tree savanna, and shrub savanna decreased by 20.8 %, 6.8 %, and 4.5 %, respectively, while cropland increased by 26.3 %, along with grass savanna by 5 %. Population growth correlated with increased agriculture and decreased vegetative area with R2 of 0.903 and 0.793, respectively. Efforts should be made to create harmony between humans and nature through various approaches such as nature-based solutions to enable efforts for the reserve sustainable management (SDG15).

Urban green space, human heat perception and sleep quality: A repeated cross-sectional study

Urban heat poses significant challenges to public health, as exposure to high temperatures is associated to heat stress, resulting in heat strain, sleep deprivation, and cardiovascular morbidity and mortality. As the frequency of heat waves is increasing due to global warming, urban green spaces are often proposed as a nature-based solution to mitigate urban heat stress. This study investigated the impact of urban green space on perceived heat stress and sleep quality, using questionnaires and detailed land cover data. We surveyed 584 respondents during four heat and four control events in the summers of 2021 and 2022, assessing perceived heat stress, sleep quality, and mental health. Using structural equation models, this study analysed the influence of both tree cover and grass and shrub cover on perceived heat stress and sleep quality, while controlling for risk and vulnerability factors. The outcomes revealed that during heat events, enhanced tree cover was associated with reduced heat stress (B = -0.484, 95% CI [-0.693, -0.275], p = 0.001), while increased grass and shrub cover was associated with both reduced heat stress (B = -0.361 [-0.529, -0.193], p = 0.000) and improved sleep quality (B = -0. 241 [-0.399, -0.083], p = 0.003). Conversely, during control events, stress indicators were more strongly associated with individual vulnerability factors rather than surrounding green space. These results emphasize the importance of combining trees with lower vegetation in urban planning to mitigate heat-related stress and enhance sleep quality, thereby improving overall well-being during heat events.

Costing of nature-based vs grey solutions for water management: cases from Nairobi

Climate change adaptation in urban Africa is a critical development issue of this century. Informal and low-income neighbourhoods in African cities are particularly vulnerable as they are often located on flood pathways. Nature-based Solutions (NbS) have been put forward as an approach to enhance flood and climate resilience in urban settings. While social and environmental benefits of urban NbS are increasingly well documented, a key gap in the literature is robust data on the cost of implemented NbS, particularly from African cities. In this paper, we compare lifecycle costs of two significant implemented NbS projects against hypothetical equivalent grey solutions, in two different informal settlements in Nairobi, Kenya. We apply comparative Life Cycle Costing (LCC) for both cases and a Cost Benefit Analysis (CBA) for one case study where historical data is available. In one of the two cases NbS was significantly cheaper, while in the other higher costs were attributed to costs required to create understanding of the new approach. We find that the cost of any solution is highly context dependent, although the NbS approach shows competitive lifecycle costs, potential for cost-optimisation as the concept matures, and highly attractive for investment when the documented co-benefits are considered.

Mapping Research Trends in Global Climate Change Adaptation to Flood Disasters: A Bibliometric Analysis using VOSviewer

Using a bibliometric analysis, this study aims to map the research trends and thematic developments in climate change adaptation to flood disasters. Data from 812 publications, spanning from 1996 to 2023, were retrieved from the Scopus database and analyzed using VOSviewer software to visualize keyword co-occurrence networks. The analysis identified five key thematic clusters: adaptation strategies and resilience (180 publications), urban planning and green infrastructure (150 publications), flood risk management (85 publications), early warning systems (60 publications), and socio-economic impacts such as health and displacement (100 publications). Over time, research output has significantly increased, particularly after 2015, with publications peaking at 150 in 2023. Regionally, Asia leads the research output with 200 publications, followed by Europe (180 publications) and North America (120 publications). The findings highlight a shift toward sustainable, nature-based solutions and the integration of advanced technologies such as machine learning in flood management. The increasing focus on the socio-economic dimensions of flood adaptation, particularly in vulnerable communities, underscores the need for more inclusive approaches. Future research should prioritize underrepresented regions, such as Africa and Latin America, and foster interdisciplinary collaboration to address the complex challenges of climate-induced floods.

Coastal Chronicles: Journey into the World of Coastal Systems

Coastal systems are complex and dynamic settings where the atmosphere, sea, and land combine to create a variety of landscapes, including coral reefs, beaches, and estuaries. These areas contribute to global sustainability initiatives delineated in the United Nations Sustainable Development Goals (SDGs), sustain biodiversity, and play crucial ecological and economic roles. For sustainable management and protection of coastal environments, it is imperative to possess an understanding of the physical attributes, biological constituents, and mechanisms that dictate their dynamics. The natural processes of tides, waves, and currents impact the geomorphology of coastal systems, resulting in the formation of features including dunes, beaches, estuaries, and deltas. Coastal vegetation that stabilizes sediments and supports a variety of habitats, like seagrasses, mangroves, and salt marshes, further enriches these landscapes. Fish, crabs, mollusks, and birds are among the coastal fauna that flourish in these habitats and add to the diversity of coastal life. However, human activities that accelerate natural processes like erosion, accretion, and sea-level riseuch as industrialization, pollution, and climate change pose an increasing threat to coastal systems. Thus, it is essential to use sustainable management techniques that strike a balance between development objectives and conservation initiatives. Coastal ecosystems must be protected and enhanced through the implementation of policies like Integrated Coastal Zone Management (ICZM), habitat restoration, and Marine Protected Areas (MPAs). A combination of mitigation and adaptation strategies, such as building coastal fortifications and promoting nature-based solutions, are also necessary for climate change adaption. We can ensure the resilience and vitality of coastal systems for present and future generations, as well as their sustained ecological and economic significance in the global environment, by tackling these intricate concerns cooperatively and comprehensively.

Microplastic retention in green walls for nature-based and decentralized greywater treatment

In wastewater treatment, two issues have recently received increased attention: nature-based solutions for addressing urban water stress through decentralized treatment and re-use; and emerging pollutants such as microplastics (MPs). At the interface of these, this study investigated living green walls for greywater treatment and their potential for MP removal.A large, pilot-scale green wall was irrigated with greywater (a mix of water collected from laundry, dishwasher, bathroom sinks, and synthetic greywater), and effluent from planted and unplanted sections was compared. MPs >50 μm were analyzed using μRaman spectroscopy and supplementary fluorescence microscopy imaging. The green wall proved efficient for the reduction of chemical oxygen demand (COD) (around 80%), removal of total suspended solids (TSS) (around 90%) and MPs, especially for MPs of the non-polar, hydrophobic polymer type polystyrene and MPs sized 100–500 μm. MP removal was improved in the planted (50–60%) compared to the unplanted section (20%), especially for the size fraction 100–500 μm. Physical filtration by the green wall growing media (a mix of perlite with a grain size of 1–5 mm, and coconut fiber), which was further enhanced by plant roots decreasing the effective pore size, can be considered the most important removal mechanism. Charge-mediated adsorption cannot be expected as MPs and growing media mix were both negatively charged at the prevailing water pH (7–8). Fluorescence imaging for MP analysis, using a merged UV/blue light fluorograph, overestimated MP concentrations in greywater (hundreds of MPs per sample were identified by fluorescence imaging versus tens of MPs by μRaman spectroscopy) and would benefit from further improvement before it can be reliably applied as a cheaper and faster alternative methodology for MP analysis.

Integrating nature-based solutions in the urbanization process by urban agriculture: a case of Bhubaneswar city, India

Nature-based solutions are approaches that draw inspiration from and are supported by nature, offering environmental, social, and economic benefits for enhancing urban resilience and sustainability. One of the greatest land use changes affecting the urban landscape is agricultural land conversion which affects the food security. Urban agriculture will not only generate livelihood opportunity for the urban poor but be the urban lung and heat sink, allow solid and water waste disposal and facilitate eco-cultural community bonding. A vast majority of the global urban dwellers live in the small and medium sized cities. However very little study has been done on urban agriculture in these areas although agricultural loss is more pronounced here. The objective of this paper is to examine through remote sensing data, in a time series between 2011 to 2023, the loss in agricultural land in one such smaller city- Bhubaneswar, which lies on a very fertile agricultural belt. This paper examines the decline of agricultural land in comparison to the rise in built up area within the specified timeframe and goes on to suggest a nature-based solution which makes the city self-sufficient in terms of food security. The research methodology involves mapping the spatial distribution of both the supply and demand for ecosystem services and quantifying the impact of Agriculture land use conversion on agriculture production. It concludes by deriving a framework which will identify the policy and governance interventions required so that the SDG goals 2 and 11.3 are realized.

Protected areas, drought, and grazing regimes influence fire occurrence in a fire-prone Mediterranean region

BackgroundExtreme fire seasons in the Mediterranean basin have received international attention due to the damage caused to people, livelihoods, and vulnerable ecosystems. There is a body of literature linking increasingly intense, large fires to a build-up of fuel from rural land abandonment exacerbated by climate change. However, a better understanding of the complex factors driving fires in fire-prone landscapes is needed. We use a global database based on the MODIS Fire CCI51 product, and the Greater Côa Valley, a 340,000-ha area in Portugal, as a case study, to investigate the environmental drivers of fire and potential tools for managing fires in a landscape that has undergone changing agricultural and grazing management.ResultsBetween 2001 and 2020, fires burned 32% (1881.45 km2) of the study area. Scrublands proportionally burnt the most, but agricultural land and forests were also greatly impacted. The risk of large fires (> 1 km2) was highest in these land cover types under dry conditions in late summer. Areas with higher sheep densities were more likely to burn, while cattle density had no apparent relationship with fire occurrence. There was also a 15% lower probability of a fire occurring in protected areas.ConclusionFuture climatic changes that increase drought conditions will likely elevate the risk of large fires in the Mediterranean basin, and abandoned farmland undergoing natural succession towards scrubland will be at particularly high risk. Our results indicate that livestock grazing does not provide a simple solution to reducing fire risk, but that a more holistic management approach addressing social causes and nature-based solutions could be effective in reducing fire occurrence.

Mainstreaming Nature-Based Solutions for Climate Adaptation in Southeast Asia: A Systematic Review

Mainstreaming Nature-Based Solutions for Climate Adaptation in Southeast Asia: A Systematic Review

Research on the Evaluation System for Agricultural Land Consolidation and Ecological Restoration Projects Based on Nature-Based Solutions

Research on the Evaluation System for Agricultural Land Consolidation and Ecological Restoration Projects Based on Nature-Based Solutions

Cost-benefit analysis of working with recovery in river management using Marxan

With the impact and cost of continued river degradation and climate change-induced extreme rainfall and floods, there is growing urgency to achieve and maintain good river health to meet global sustainable development goals. Up-scaling and working with nature-based solutions at regional, catchment and fluvial corridor scales is critical. One way to achieve this is to work within a recovery-enhanced approach to river rehabilitation, incorporating processes of geomorphic and vegetative recovery to build fluvial corridors in areas where they have become fragmented. Geomorphologically-informed cost-benefit analysis has not previously been applied in a riverine or riparian context, at the catchment or regional scale needed. We applied Marxan in a novel manner to undertake the first cost-benefit analysis for geomorphologically-informed rehabilitation of river systems. We estimated that to rehabilitate 75,500 km of streams in coastal catchments of NSW will cost $8.2 billion, comparing favourably to recent single flood event insurance losses, and projected future losses. We developed Marxan scenarios based on three broad approaches to river management: ad hoc and reactive, working with recovery and corridors, across current and future time periods. We found there are considerable current and flow-on future financial and non-financial benefits, and lower initial total and per-hectare rehabilitation costs, by fully adopting working with recovery or corridors approaches and moving away from the ad hoc and reactive approaches which dominate current practice. Implementing targeted rehabilitation based on a rolling sequence over time of corridors scenarios provides optimal holistic solutions to improve geomorphic condition and enhance recovery potential at landscape-scale. Our study demonstrates the use of Marxan as an accessible tool to address prioritisation complexity, and to run and cost landscape-scale rehabilitation scenarios over time. Our study also demonstrates the positive offsite feedbacks that occur through multiplier effects, as recovery occurs, and corridors are built. Geomorphologically-informed decision making becomes more robust, transparent, cost-effective, consistent across catchments, and adaptive to local situations and evolving river management priorities.

Are Nature-based Solutions for Built Heritage Conservation Resilient to Climate Change? The Response of Grass-based Soft Caps in Britain and Ireland to Future Climate Scenarios

ABSTRACT Nature-based solutions (NbS) offer an exciting opportunity to work with nature to conserve heritage sites and objects. Soft capping is a novel form of NbS used commonly in Britain and Ireland to help conserve ruined and free-standing walls; soil and vegetation is placed on the wall head to help reduce deterioration by buffering thermal fluctuations and regulating moisture. While this conservation practice has proved cheaper and more effective at reducing deterioration than traditional hard capping, soft caps need to be resilient to future environmental changes. Previous research has shown that the sedum species commonly used in soft caps are vulnerable to climate change. Thus, following feedback from an interactive webinar with practicing heritage professionals, here we assess the climate resilience of four grass species commonly found in western Europe as possible soft-capping species: Festuca rubra (red fescue), Poa pratensis (smooth meadow-grass), Catapodium rigidum (fern-grass) and Poa annua (annual meadow-grass). We use species distribution modelling (Maxent) to assess the likelihood of species survival by mid and end century based on presence probabilities derived using three climate models (HadGEM3-GC31-LL, IPSL-CM6A-LR, and MIROC6). Results show that all four species are resilient under mid-century projections, and P. annua proved resilient under all scenarios. Therefore, using turf-based soft caps incorporating one or more of these grass species could enhance the future resilience of this conservation technique. Given the growing interest in the use of nature-based approaches to heritage conservation, our study represents an important attempt to account for and adapt to a changing climate.

Sedimentation enhancement and its retention through integration of vegetation with permeable groin-like structure in tidal river

Sediment management in the Ganges-Brahmaputra-Meghna (GBM) delta system is considered as one of the challenging issues, even though several studies clarified that unlike many other deltas, it is receiving sufficient sediment to counterbalance the sea level rise. Therefore, it is important to materialize such potential using appropriate techniques through utilizing the natural power of the flow-sediment regime, especially in the tidal rivers. Towards the development of nature-based solution (NbS), the principles of bandal-like structure, a V shape permeable groin-like structure was designed for the bidirectional tidal environments and applied in a tidal reach of the river Pyra. It is found that the structure has a high potential to enhance sedimentation along the bank line, while having difficulty in retaining the trapped sediment within the complex flow-sediment regime of tidal environment. To overcome such a problem, different types of vegetation are integrated with this structure to test the potentiality of vegetation in accelerating the sedimentation and its retention in the study site. Through systematic monitoring of the growth of vegetation and their performance it was found that only the site-specific native vegetation (Hogla and Shoila) grew well, while other planted species did not survive. Moreover, continuous maintenance and proper nursing of plants were required against the hydrodynamic stresses and human and animal interventions till their maturity. Several parameters related to vegetation-flow-sediment data were collected by using ADCP, Eco sounder, total station, and soil sampling to clarify the changes in flow and soil parameters due to vegetation. The results reveal that the cohesiveness of the soil increases by about 72–110 % and flow velocity reduces by 35–40 % in the area with densely grown vegetation having flow depth < 5 m. While velocity reduction is relatively low (10–15 %) in the area with sparsely grown vegetation and having flow depth > 5 m. Such flow reduction resulted in enhanced sedimentation and deceased erosion, whereas the increased soil cohesiveness resulted in retention of already deposited soil and bank and bed stabilization.

The role of engineered tree pit solutions in nature-positive civil engineering

Successfully establishing and growing street trees presents significant challenges and traditional techniques are associated with elevated tree mortality. Moreover, securing appropriate soil volumes for trees is a substantial challenge, particularly in modern street engineering where the grey infrastructure is prioritised over tree success. Engineered tree pit solutions can counteract this situation. They enable trees and grey infrastructure to coexist, providing improved rooting environments, load-bearing structural support conforming to engineering specifications, and the ability to manage stormwater runoff within one tree pit design. This article presents a literature-informed overview of the current technologies applicable to new-build and retrofit scenarios that integrate street trees and pavements, enabling nature-positive, resilient tree pit designs conducive to tree growth. We focus on the solutions most commonly employed in practice – structural growing media and crate systems – outlining their constituents, construction and considerations for success. This article informs built environment practitioners, policymakers and researchers on innovations translatable into practical techniques to enhance tree pit design and optimise street trees as multifunctional nature-based solutions.

Vertical growth rate of planted vegetation controls dune growth on a sandy beach

The integration of coastal dunes planted with vegetation and dikes combines traditional infrastructure with dynamic aeolian sediment and ecological processes to enhance coastal resilience. The functioning of such dune-dike hybrid Nature-based Solution strongly depends on aeolian sediment transport and the vertical growth rate of vegetation. We used the AeoLiS numerical model to investigate the relative importance of aeolian and vegetation dynamics in the evolution of a 120 m long and 20 m wide marram grass-planted dune field on a Belgian sandy beach backed by a seawall, constructed in 2021. AeoLiS proved to be a promising tool for predicting these systems, effectively capturing aeolian sediment deposition, vegetation growth, and profile development three years post-construction. Seasonal variations in vegetation trapping efficiency, driven by sediment burial, and seasonal plant growth emerged as important factors controlling dune growth. Profile development discrepancies were attributed to unaccounted biotic and abiotic factors, highlighting the complexity of coastal eco-geomorphological processes. Dunes planted with vegetation wider than 20 m were identified to enhance sediment trapping without an increase in dune height. These findings offer actionable insights for coastal management, promoting strategic dune design and planting approaches to reinforce shoreline resilience. Additionally, the findings underscore the necessity for advancing eco-morphodynamic models and deepening our knowledge of coastal dune dynamics.

Evaluating the Economic Viability of Agro-Ecotourism as a Nature-Based Solution for a Climate Adaptation Strategy: A Case Study of Yuanshan Township, Taiwan

This study applied the contingent valuation method to evaluate the economic viability of climate adaptation policies in the climate-fragile Yuanshan Township (YST), Taiwan, focusing on the balance between forest conservation and local livelihoods. Traditional agriculture in YST is transitioning to agro-ecotourism, supported by leisure-oriented and hillside forest protection policies that attract visitors and cause the local economy to thrive. This research used non-market valuation methods to quantify the value of local recreational resources perceived by visitors at NTD 1002.00 per visitor. The findings indicate that visitors’ willingness to pay for these resources is significantly influenced by their intention to revisit YST, their trust in local conservation efforts, their gender, and their income. The value that visitors place on recreational resources and the aforementioned significant determinants of their willingness to pay highlight the economic potential of agro-ecotourism in supporting both environmental sustainability and community income. This study emphasizes that successful nature-based climate adaptation must consider the economic interests of resource users and local residents. Agro-ecotourism in YST is shown to be a viable policy for balancing forest conservation with societal benefits, providing a model for the sustainable management of local resources. The economic benefits from this transition underscore the feasibility of agricultural transformation for community income generation and climate resilience, demonstrating that environmental and economic goals can be mutually supportive in addressing climate change.

Integrated crop-livestock-forestry systems as a nature-based solution for sustainable agriculture

Integrated crop-livestock-forestry systems as a nature-based solution for sustainable agriculture

Leveraging Greenspace to Manage Urban Flooding: An Investigation of Nature-Based Solutions Implementation in U.S. Public Parks

Many cities are looking to adopt nature-based solutions (NBS) in greenspace to manage urban flooding and provide diverse co-benefits. Yet little research exists to inform the planning and design of park NBS. This study investigated NBS adoption in 58 public parks across major U.S. cities, using a 2022 survey by the Trust for Public Lands and other secondary datasets. We developed a typology to conceptualize a wide range of park NBS into five high-level categories by size/capacity, location of the gray–green spectrum, and design objectives. We then employed this typology to explore how a park’s adopted NBS types may relate to its landscape and sociodemographic contexts. We found that the most used type of NBS in the studied parks was ECO (a typology we defined as conserving, restoring, or creating ecosystems to mitigate flooding through ecological processes and functions), while the least used NBS type was ENG (a typology we defined as imitating natural infiltration processes but having no living elements). Further, parks that adopted ECO had significantly higher percentages of greenspace in the surrounding, as well as higher flood risks. We also found notable—though not statistically significant—evidence of potential associations between the type of NBS implementation in a park and its nearby neighborhoods’ income level, poverty, and population racial and age compositions. Moreover, our findings indicated that park visitors were more privileged compared to residents living near a park. We concluded that park contextual factors deserve more explicit consideration in the planning and design of NBS and discussed key implications of this study for practice and future research around park NBS for urban flooding.

Addressing the climate adaptation tracking gap: an assessment method and its application to the Caribbean region

This article addresses the climate adaptation tracking gap. Indeed, we still ignore the intensity, nature, spatial distribution, effectiveness, and recent evolution of adaptation efforts at the national, regional, and global scales. We propose a web-based replicable assessment method using key variables to document adaptation efforts: country/territory, location, goal, implementation date, type of action, holder, funding source. Applying it to the Caribbean region, we analyzed 100 coastal adaptation actions. This studies the method while also highlighting the difficulties faced to track adaptation. We found that coastal adaptation efforts are substantial and increasing in the Caribbean, revealing the use of diversified adaptation actions; prevalence of hard protection (51%); increase use of Nature-based Solutions (22%); limited use of retreat (6%); and accommodation (2%). Combined actions (17%) increased over time, due to the failure of single actions and need to find tradeoffs between human asset protection encouraging hard protection and the maintenance of attractive tourist beaches encouraging beach nourishment. Puerto Rico and Trinidad and Tobago fall under the engineering-based “one-size-fits-all” adaptation model, whereas Jamaica and Barbados experiment diversified options and combinations of options. Jamaica, Puerto Rico, Trinidad and Tobago, and Barbados are particularly active in taking adaptation action, while most dependent islands and sub-national island jurisdictions have no adaptation action reported. Considering the advantages and limitations of a web-based method compared to a field-based approach, we recommend the combined use of these two complementary approaches to support adaptation tracking and help structuring communities of practice to the benefits of decision-makers and practitioners and scholars.

Soil amendments and water management to improve attenuation and recovery of wastewater originated nutrients through a vegetation filter

Vegetation filters (VFs) are on-site wastewater (WW) treatments that can be considered as a nature-based solution (NbS). They are green infrastructures that provide several environmental benefits such as non-potable water reuse, contamination reduction, biomass production, landscaping improvements and CO2 fixation, among others. However, nutrient leaching, especially nitrate, partially exists. To overcome this limitation, operational parameters related to the irrigation water management and soil amendments were tested in a real system receiving WW from an office building operated along 4 years.The attenuation of N is improved (up to 83%) in the vadose zone by boosting biodegradation. Lower hydraulic loads and more frequent irrigation events using drippers and the incorporation of woodchips as a layer above the topsoil promote denitrification processes. Changes in organic carbon characteristics also confirm that biodegradation is enhanced.P attenuation is a result of abiotic processes, mainly driven by chemical equilibriums between the liquid and the sorbed and/or precipitated phase and, when uncontrolled changes in the WW quality occurs, removal efficiency is negatively affected. However, only 10% of the samples collected at 45 cm depth present concentrations above 2 mg/L. The woodchips application does not seem to ameliorate P removal regardless of the application method.The implemented measures allow higher soil water content, infiltration and groundwater recharge and prevents aquifer contamination.