Green Infrastructure Strategies Research Articles

Optimizing green infrastructure strategies for microclimate regulation and air quality improvement in urban environments: A case study

With an increasing global urban population andassociated health concerns, understanding the effects of urban microclimate and air quality is crucial. This study aims to assess the influence of different types and locations of greenery, along with building heights and wind orientation, on urban canyon microclimate and air quality. Focusing on PM10, PM2.5, and NOx concentrations in a hot-arid district, the research employs simulation-based analysis. Results indicate that stepped buildings with green walls exhibit the highest temperature (18.02°C), while scenarios featuring two rows of deciduous trees showcase the lowest temperature (17.56°C) but higher pollution levels. Notably, scenarios lacking trees exhibit elevated temperatures. The study introduces a novel ventilation design pattern for effective air pollutant removal and proposes a scenario with extensive green coverage on streets, walls, and rooftops, incorporating appropriate planting techniques and plant selection. The findings offer valuable insights for urban designers and architects seeking to create more sustainable and environmentally friendly cities.

Disseminating land use land cover change scenarios for improving the role of blue and green infrastructure: Evaluation and perspectives

Land use land cover (LUCC) scenarios are often co-produced by researchers and a reduced group of local actors. While most scenarios’ evaluations analyse feedback from actors involved in the scenarios making, restricting the diffusion of scientific results to the co-construction group can limit their potential to support land management. In this study, we investigate if disseminating LUCC scenarios to a broad and heterogeneous audience is effective in overcoming socio-cultural and knowledge-related barriers to blue and green infrastructure (BGINs). We presented LUCC scenarios that study the impact of different blue and green infrastructure strategies on water resources and biodiversity. In 12 workshops, we collected feedback from 147 local actors, including representatives, water management technicians, farmers and students. Findings indicate that despite the original aim of the scenarios being to support the integration of BGINs in land management, the primary benefits were a deeper understanding of future land management challenges and cause-effect relationships between different landscape elements and socioeconomic drivers of change. In addition, we observed that respondents’ professional activity significantly influences the evaluation. We conclude that, while scenarios can be an effective tool in overcoming some of the barriers of BGINs, the outcomes of scenarios can be maximised by making the expected outcomes (including conceptual ones) explicit and by acknowledging local actors’ roles in land management during the dissemination.

Modeling benefits and tradeoffs of green infrastructure: Evaluating and extending parsimonious models for neighborhood stormwater planning

Green infrastructure is often proposed to complement conventional urban stormwater management systems that are stressed by extreme storms and expanding impervious surfaces. Established hydrological and hydraulic models inform stormwater engineering but are time- and data-intensive or aspatial, rendering them inadequate for rapid exploration of solutions. Simple spreadsheet models support quick site plan assessments but cannot adequately represent spatial interactions beyond a site. The present study builds on the Landscape Green Infrastructure Design (L-GrID) Model, a process-based spatial model that enables rapid development and exploration of green infrastructure scenarios to mitigate neighborhood flooding. We first explored how well L-GrID could replicate flooding reports in a neighborhood in Chicago, Illinois, USA, to evaluate its potential for green infrastructure planning. Although not meant for prediction, L-GrID was able to replicate the flooding reported and helped identify strategies for flood control. Once evaluated for this neighborhood, we extended the model to include water quality through the representation of dispersion and settling mechanisms for two pollutant surrogates—total nitrogen and total suspended solids. With the extended model, Landscape Green Infrastructure Design Model-Water Quality (L-GrID-WQ), we examined benefits, costs, and tradeoffs for different green infrastructure strategies. Bioswales were slightly more effective than other green infrastructure types in reducing flooding extent and downstream runoff and pollution, through increased infiltration and settling capacity. Permeable pavers followed in effectiveness and are suggested where spatial constraints may limit the installation of bioswales. Although green infrastructure supports both flooding and pollution control, small tradeoffs between these functions emerged across spatial layouts: strategies based on only curb-cuts better controlled pollution, while layouts that followed the path of water flow better controlled flooding. By illuminating such tradeoffs, L-GrID-WQ can support green infrastructure planning that prioritizes unique concerns in different areas of a landscape.

Visual Preferences of College Students for an Ecological Design Project in a Campus Environment

In the last few decades, the integration of ecological design in urban landscapes has gained significant attention from researchers, practitioners, and administrators because of its potential to address environmental challenges and enhance the quality of life. While there are many benefits of integrating ecological design in urban landscapes such as environmental conservation and awareness, its aesthetics have remained a critical, yet often overlooked, aspect. This paper examines the visual preferences of college students for ecological design through a rain garden project at Izmir Katip Celebi University. Ecological design includes green infrastructure strategies like rain gardens that play a major role in creating sustainable urban areas. In this study, we conducted surveys among students at Izmir Katip Celebi University regarding a rain garden project that would be implemented on campus. We provided six rain garden design images, each representing various visual attributes in the survey. The survey also included questions about aesthetic appeal, ecological significance, preferred design choice, and demographic information. We collected the data from 120 respondents and analyzed responses using descriptive statistics. The study findings presented that Image 6, featuring colorful plant selections, received the highest aesthetic rating, while Image 4, with canopy trees, stood out as the most ecologically significant design.

Assessment of Policy and Legal Frameworks of Urban Green Infrastructure Development: Republic of Guinea

Urban green infrastructure has become crucial to sustainable cities’ development because it offers many advantages, including better environmental quality, increased social well-being, and increased economic prosperity. The evaluation and monitoring of the implementation of policies are essential elements of the development of urban green infrastructure because they demonstrate the will of political decision-makers to assess the implementation’s success and adapt it to the observed need. This article sets out existing institutional structures, institutional plans, and institutional policies linked to creating urban green infrastructure in three study cities: Conakry, Kankan, and Dubreka. The collected data were analyzed using descriptive statistics and policy analysis. The study used primary data collection methods, including questionnaires and interviews with key informants, to gather first-hand information from decision-makers, planners, managers, and other organizations involved in developing and managing urban green infrastructure at regional and local levels. In addition, this study used primary data collection, facilitating the collection of first-hand information reinforced by questionnaires. A simple random sampling method was also adopted, which improved the selection of a sample of 330 respondents. Most government officials and academics agree that current policies regarding green urban infrastructure have not been implemented. The study has identified several shortcomings in existing political and legal frameworks, in particular the lack of coordination and coherence between the ministries and the government agencies involved, insufficient financial and human resources, the lack of attention, the lack of transparency in the process of developing policies and regulations, the low involvement of the private sector, the need to strengthen technical capacity, and poor urban green infrastructure strategies. These actions are necessary to develop essential policies and procedures that improve the development of green urban infrastructure. In order to overcome these obstacles, efforts must be made to improve coordination and collaboration between stakeholders, strengthen technical capacity, increase public participation, and improve transparency in the process of policies and regulation.

How to quantify the cooling effects of green infrastructure strategies from a spatio-temporal perspective: Experience from a parametric study

Urban green infrastructures (GI) are efficient nature-based solutions for urban heat mitigation. Typically, three GI typologies, i.e., green roof, green wall, and street tree, are often recommended and implemented for outdoor thermal comfort modification and passive energy saving. However, the current evaluation of the cooling effects for GI strategies is not comprehensive for two reasons: 1) lacking a holistic assessment to involve different combinations of GI typologies; 2) lacking a spatio-temporal lens to quantify the cooling effects.This study proposes a systematic approach to quantify the cooling effects of GI strategies from a spatio-temporal perspective. Through a parametric study in ENVI-met model, the cooling effect of seven GI strategies were quantified, and different street orientations and sky view factor (SVF) were also involved. Three cooling indicators were proposed for different sustainable planning targets: cooling intensity (CI), cooling area (CA), and cooling duration (CD). The results showed that the seven GI strategies performed differently under various urban morphologies. The greatest cooling effect of GI strategies was observed at SVF = 0.7, after which additional strategies may be needed for urban heat mitigation. Three proposed indicators were found to show similar patterns across the GI strategies, but revealed the details of cooling effects differently.Overall, this study represents the first assessment of the cooling effects of seven GI strategies across different morphological settings. The evidence-based understanding contributed by this study can help planners and designers to optimize the thermal environment in subtropical climate. The systematic approach from a spatio-temporal lens can be transferred to other cities and climate backgrounds.

Thermal Comfort in the Built Environment: A Digital Workflow for the Comparison of Different Green Infrastructure Strategies

The green transformation of the built environment is aimed at improving sustainability and can be supported by digitalization, which has become a significant tool to support the supply, integration, and management of information throughout the construction life cycle. In addition, climate change highly affects human comfort in the built environment and different strategies should be evaluated for adapting cities. This paper developed a digital workflow by integrating existing tools (i.e., Grasshopper, Ladybug, Honeybee, and Dragonfly) to evaluate how different green infrastructure strategies affected the thermal comfort by reducing the UTCI. The workflow was applied to a typical historical urban context (Catania, South of Italy), consisting of a square surrounded by three-floor buildings. Three basic scenarios were created that depended on the pavement material used in the built environment: a black stone pavement (reference material from Mount Etna), a permeable pavement, and grass. These three scenarios were combined with different green infrastructure strategies: tree pattern on the square, green walls and green roofs on the surrounding buildings, and the integrations of all these above-mentioned strategies. The results demonstrated that the integration of different green strategies (a grass square instead of pavement, with trees, and green walls and green roofs) increased the thermal comfort by reducing the UTCI by more than 8 °C compared to the existing urban context (black stone pavement and building envelope). However, this temperature reduction was highly affected by the location of the human body into the urban context and by the evaporation rates from vegetation. The workflow developed will be useful for designers to evaluate the effectiveness of different green strategies during the early-design stage in mitigating and adapting cities to climate change.

User Satisfaction and the Social and Environmental Benefits of Urban Green Spaces: A Case Study of Thimphu City, Bhutan

Urban green spaces provide important recreational, social, and ecological benefits in urban settings. Understanding of the use and benefits associated with green spaces amongst urban residents is crucial in developing appropriate urban green infrastructure strategies. This study explored visitors’ levels of satisfaction with the benefits, characteristics, and determined factors influencing visitor satisfaction with urban green spaces. Data were collected through a questionnaire survey from a random sample of 125 visitors from three urban green spaces in the capital city of Bhutan, Thimphu. Visitors' satisfaction with urban parks was assessed based on their quality, social, and environmental benefits. Descriptive statistics and an ordered logistic-regression model were used to analyze the data. Results indicate that visitors were satisfied with quality as well as the social and ecological benefits of green spaces. Results also revealed that factors significantly influencing visitor satisfaction included educational level, frequency of visit, day visit, distance from home, quality of the urban park, social benefits, and ecological benefits. Overall, the study stresses the importance of optimizing green infrastructure planning in order to promote social and environmental well-being in the face of the growing populations in urban areas.

Post-Pandemic Urbanism from the Perspective of Healthy Cities: Evaluation of Urban Green Space Sufficiency in Denizli

The COVID-19 pandemic has re-bought forward the importance of urban open spaces. The scarcities of public spaces and open green spaces have been effective in keeping the city dwellers in their homes due to the need for isolation during the pandemic era. Despite this, cities with sufficient open green spaces have increased the mobility of city dwellers since people interact less with each other. In the process of re-planning urban areas, developing an integrated approach with green infrastructure strategies in parallel with designing resilient cities has the potential to create healthier cities. In this context, the PP-GS (Post-Pandemic Green Spaces) model of the study reveals the minimum amount of green spaces required per capita in the cities, based on the social distance and healthy living principles that emerged during the pandemic. The study examines the required amount of green space in the Denizli urban center based on the PP-GS model from the perspective of healthy cities and proposes spatial suggestions for post-pandemic urban green space planning.

Transformation pathways towards sustainable urban development by the inclusion of peri-urban farmland in green infrastructure strategies

Urbanization and agricultural land use are two of the main drivers of global changes with effects on ecosystem functions and human wellbeing. Green infrastructure is a new and promising approach in spatial planning contributing to sustainable urban development, but rarely considers spatial and functional potentials of utilizable agricultural land as an integral part. This doctoral thesis addresses this gap and investigates how peri-urban farmland can promote green infrastructure and sustainable urban development. The results contribute to the conceptual understanding of urban green infrastructures as a strategic spatial planning approach that incorporates inner-urban utilizable agricultural land and the agriculturally dominated landscape at the outer urban fringe. Four strategies are introduced for spatial planning with the contribution to a strategically planned multifunctional network. Finally, this thesis sheds light on the opportunities that arise from the integration of peri-urban farmland in the green infrastructure concept to support transformation towards a more sustainable urban development. This work concludes that the linkage of peri-urban farmland with the green infrastructure concept is a promising action field for the development of new pathways for urban transformation towards sustainable urban development. Along with these outcomes, attention is drawn to limitations that remain to be addressed by future research.

The challenges of urban river restoration and the proposition of a framework towards river restoration goals

River restoration is gaining significance as an approach for river system management, even in urban areas, where the flood risks and morphological imbalances are more evident. In cities, the highly modified environment and the lack of open spaces make it harder to apply the concept of river restoration in its whole extent, raising doubts about the feasibility of adopting restoration approaches for urban rivers. In some cases, the implementation of green and blue infrastructure strategies alone is not enough to support the river restoration goals so the adoption of gray infrastructure is necessary. In order to explore aspects related to the theme, this article discusses four questions proposed from a bibliometric study of urban river restoration: Is it worth restoring urban rivers? How much does it cost? If the watershed is heavily modified, can it sustain the restored fluvial spaces? How can the success of this approach be measured? Throughout the discussion, it is clear that due to cities’ complexity and the absence of available open spaces, there is no simple answer to these questions, each case being unique and deserving particular assessment. However, even when performed partially, without significant positive impacts on the natural environment, river restoration can bring several benefits to the urban environment, creating an opportunity of reintegrating the river as a valuable element of the landscape. Additionally, we propose a framework to assist managers in identifying and implementing potential river restoration actions.

Quantitative evaluation of the mitigation effect of low-impact development pavement materials on urban heat island and tropical night phenomena.

Rapid urbanization has led to altered thermal circulations in major cities that are responsible for the increasing occurrence of urban heat islands (UHIs) and events such as tropical nights and heat waves. To effectively mitigate such events, low-impact development (LID) and green infrastructure strategies have been developed. In Korea, LID techniques focus mainly on road pavement materials; however, issues regarding the reliability of measurements due to differences in the measurement equipment and studied specimens persist. This study presents the design of a green infrastructure surface temperature measurement (GSTM) instrument and a reliable methodology developed to evaluate the performance of pavement materials under controlled climate conditions. The developed GSTM instrument and methodology were tested by monitoring the surface temperature of materials based on LID practices and dense-graded asphalt and evaluating their ability to mitigate UHI and tropical night phenomena. The experiments were conducted under controlled climate conditions, using summer climate conditions of Seoul's typical meteorological year data. The UHI and tropical night phenomena mitigation performance of the pavement materials was evaluated by analyzing the correlation between the pavement materials' albedo and surface temperature using porous block specimens of different colors and LID-based pavement materials. The greening block recorded the most significant reduction in surface temperature, showing a difference of 22.6 °C, 185 min to the dense-graded asphalt. The white and yellow porous blocks showed surface temperature differences of 10.2 °C and 8.2 °C respectively compared to the dense-graded asphalt. The results revealed that pavement materials with higher albedo, more evaporation, and lower heat capacity have superior performance in mitigating UHI and tropical night events.

Are green infrastructure strategies suitable in arid climates? a design feasibility study from Jeddah city, Saudi Arabia

Are green infrastructure strategies suitable in arid climates? a design feasibility study from Jeddah city, Saudi Arabia

Assessing the performance of gray and green strategies for sustainable urban drainage system development: A multi-criteria decision-making analysis

The performance assessment of a sustainable urban drainage system (SUDS) involves multiple criteria and is important for the decision-making of urban sustainable development. In this study, we intend to balance the comprehensiveness and objectivity in the performance assessment of SUDS development through a combination of multi-criteria decision-making (MCDM) analysis and mathematical quantification. We proposed an MCDM framework with eight quantifiable indicators, including flood mitigation capacity, pollution control capacity from technical criteria, life-cycle cost, damage cost, recreational function from socioeconomic criteria, biotope area ratio from ecological criteria, and spatial consistency from political criteria. A city-scale model based on engineering datasets and satellite images was created to implement gray and green infrastructure strategies in the studied area. Results revealed that gray strategies performed better in hydraulic improvements, mitigating approximately 17% of flood magnitude and decreasing over 20% of flood-induced damage. Green strategies were more eco-friendly, removing approximately 60% of non-point pollution and improving at most 15% of the ecological level. Integrated assessment demonstrated that the combine-used strategy showed the overall best performance, with a sustainability index of 0.676. Therefore, the methods and results in this study could provide additional improvements in the decision-making process of SUDS development.

The capitalized amenity of green infrastructure in single-family housing values: An application of the spatial hedonic pricing method

The environmental benefits of having retention/detention ponds as major stormwater management facilities in a neighborhood have been well documented since the adoption of green infrastructure strategies in early 1990s. However, the capitalization effect of stormwater treatment ponds in real estate values still remains unclear. This study developed classic hedonic pricing and spatial econometric models to examine the capitalization effects of neighborhood-level detention and retention ponds using both cross-sectional and longitudinal housing prices. The housing market value from 2007 to 2016 was assessed in four subdivisions in Houston, Texas. A subdivision, located in the upper neighborhood, had retention ponds which were converted from detention ponds in 2011, while three subdivisions in the lower neighborhood had detention ponds over the same study period. The study results show that living near retention ponds has positive capitalization impacts on single-family housing prices, not only cross-sectionally but also longitudinally. In contrast, maintaining detention ponds depreciates housing values, and living nearby lowers the price increase over a decade. The findings in this study imply the importance of converting stormwater facilities into a park-like amenity to enhance aesthetic value and generate long-term economic benefits to a neighborhood.

Is green infrastructure a viable strategy for managing urban surface water flooding?

ABSTRACT Green infrastructure strategies are often cited as best practice for urban water management; however, limited research has been undertaken to compare intervention effectiveness during moderate to extreme intensity rainfall events which are typically responsible for surface water flooding. This research responds to this through applying a cellular automata-based rapid scenario screening framework to predict the flood management performance of green infrastructure strategies across an urban catchment in Melbourne City Centre (Australia). Key findings indicate an intensive application of green infrastructure could substantially reduce flood depth and velocity in the catchment but that residual risk remains, particularly during extreme flood events. The best performing intervention strategy in the study area was found to be catchment-wide decentralised rainwater capture. The research also evidences the utility of rapid scenario screening tools to complement existing flood modelling approaches through screening management strategies, exploring scenarios and engaging a wide range of multi-disciplinary stakeholders.

Green Infrastructure as a Solution to Hydrological Problems: Bioswales and Created Wetlands

Green infrastructure is an ecological landscaping method that was first theorized in a 1994 Floridian report titled Creating a Statewide Greenways System, which was presented to the governor at the time, Lawton Chiles (Florida Greenways Commission, MacKay, & Reed 1994). As defined by the European Commission, green infrastructure is “a strategically planned network of natural and semi-natural areas with other environmental features designed and managed to deliver a wide range of ecosystem services” (Communication from The Commission to The European Parliament, 2013, p. 3). This paper will examine two green infrastructure strategies – bioswales and created wetlands – which are crucial in solving some of the water problems that Florida faces. Bioswales are engineered green spaces that collect runoff and remove harmful pollutants from the stormwater before it is discharged into surface water sources. This paper will examine how bioswales function. Besides polluted storm water, the other major water problem is eutrophication. Created wetlands are effective ecological tools for mitigating eutrophication, which is the result of excessive nutrients in water bodies that cause algal blooms and subsequently suffocate other organisms in the water by depleting oxygen. Freedom Park in Naples, Florida is composed of four created freshwater marshes, which filter runoff and reduce heavy metals and nutrients in the stormwater before it enters the Gordon River. This paper examines Freedom Park in Naples, Florida to assess how created wetlands can assist in reducing nutrient loads, mitigating pollutants in stormwater before it enters natural waterways, and restore habitat.

Green Infrastructure Solutions to Health Impacts of Climate Change: Perspectives of Affected Residents in Detroit, Michigan, USA

Cities worldwide are incorporating green infrastructure to mitigate climate change and achieve health cobenefits. However, green infrastructure projects are often distributed inequitably based on race and class. Residents’ perspectives are necessary to develop and enact effective and equitable ‘green’ strategies to address climate change and its health impacts. This study reports findings from interviews and ethnographic observations with diverse residents of Detroit, Michigan, USA, who have experience with both green infrastructure projects and intense weather events (flooding). Residents expressed widespread support for green infrastructure solutions, while also sharing concerns about unintended health consequences from unsatisfactory governance of green spaces and climate change itself. Residents also held differing perspectives regarding their responsibility for, and capacity to enact, these solutions compared to businesses, city government, and nonprofit organizations. These findings illuminate key factors that city governments and partnering institutions should incorporate into planning processes with residents to achieve greater environmental justice through green infrastructure strategies to mitigate climate change and related health impacts.

The science-practice interface of connectivity in England

A disconnect has been identified at the interface between landscape science and practice. More commonly, it is assumed that better or more targeted science would lead to better practice. Others argue that such a view is partial, and propose an understanding that foregrounds how social and political factors shape the science-practice interface. In this study we explore how (the combination of) different conceptualisations, novel governance architectures, and political-economic conditions shape the science-practice interface between landscape ecology and practice, using connectivity conservation and enhancement initiatives in England as a case study. We conducted interviews (n = 36) with practitioners involved in connectivity-related projects (predominantly Nature Improvement Areas and Green Infrastructure initiatives). We transcribed and analysed the interviews using standard methods of qualitative analysis. We also conducted a desk study of green infrastructure strategies (n = 58 documents). Enhancing or maintaining connectivity is perceived positively by conservation and planning practitioners in England. Considering both planning and ecological contexts, quantitative assessments are rare on the ground. Conceptual ambiguity, lack of resources (time, personnel, software and hardware), novel governance architectures, and changing economic and political conditions are implicated. We find that the co-articulation of conceptual ambiguity and resource issues with novel forms of governance in changing economies is diminishing opportunities and creating challenges for (ecological) connectivity conservation. This is particularly true in relation to large scale operationalisation that requires multi-scale and multi-partner coordination.

How to Connect Site-scale Projects and City-scale Green Infrastructure Strategies

How to Connect Site-scale Projects and City-scale Green Infrastructure Strategies