Green Roofs Research Articles

Determining the Role of Urban Greenery in Soil Hydrology: A Bibliometric Analysis of Nature-Based Solutions in Urban Ecosystem

Nature-based solutions play an essential role in enhancing urban soil hydrology by improving water retention properties, reducing surface runoff, and improving water infiltration. This bibliometric analysis study reviewed the literature and identified the current trends in research related to nature-based solutions in urban soil hydrology. The study has the potential to highlight current research areas and future hot topics in this specific field. The research used the Scopus database to collect published articles from 1973 to 2023. The keywords (“trees” OR “vegetation” OR “green infrastructure” OR “blue green infrastructure” OR “greenery” OR “nature-based solutions” AND “hydrolog*” AND “urban” OR “city” OR “soil”) were searched in the Scopus database, and 13,276 articles were retrieved. The obtained publications were analyzed for bibliometric analysis by using Bibliometrix (v4.3.0) and VOSviewer (v1.6.20) software. The maximum number of publications (970) related to nature-based solutions and urban soil hydrology was published in 2023. Additionally, countries such as the United States and China published 54.2% of articles of the global research in the field of nature-based solutions and urban soil hydrology, with 36% from the USA and 18.2% of articles from China. The bibliometric analysis depicted that Beijing Normal University led this specific research field with 540 articles. The top country in terms of collaboration was the USA, with 26.17% as compared to the global countries. The most productive researcher identified was Jackson, T.J., as he had the highest number of publications, showing his considerable contribution to the field. Furthermore, the most frequent keywords used in this research area were hydrology, ecosystem services, urban hydrology, remote sensing, nature-based solutions, climate change, runoff, stormwater management, water quality, vegetation, green roof, bioretention, and land use. The early research trending topics in this field from 2015 to 2023 were remote sensing, soil moisture, climate change, drought, green infrastructure, machine learning, and nature-based solutions. The bibliometric analysis identified limited interdisciplinary research integrations, not using well-significant and standardized methodologies for the evaluation of urban soil hydrology, and under-representation of research from developing countries as current research gaps. Future research directions highlight advanced methods such as combining data-driven technologies with traditional hydrological approaches, and increasing international collaboration, specifically in developing nations, to address urban soil hydrological problems properly.

Dynamics of Contaminant Flow Through Porous Media Containing Random Adsorbers

Many porous media are mixtures of inert and reactive materials, manifesting spatio-chemical heterogeneity. We study the evolution of scalar transport in a chemically heterogeneous material that mimics a green roof soil substrate, fractionally composed of inert and reactive adsorbing particles. These adsorbing particles are equivalent to biochar within a real soil substrate. The scalar transport evolution is determined using experiments and simulations calibrated from experimental data. Experiment 1 is used to determine the equilibrium capacity and adsorption rate of two biochar types when immersed in a methylene blue solution. Breakthrough curves of a packed bed of glass beads with randomly interspersed biochar are determined in experiment 2. Simulations are then run to investigate the solute transport and adsorption dynamics at the pore-scale. An analytical model is proposed to capture the behavior of the biochar adsorption capacity, and the simulation results are compared with experiment 2. A pore-scale analysis showed that uniformly sized beds are superior in contaminant breakthrough reduction, which is related to the adsorptive surface area and the rate at which adsorption capacity is reached. Cases using the adsorption capacity model display a tight distribution of particle surface concentration at later simulation times, indicating maximum possible adsorption. The beds with dissimilar particle sizes create more channeling effects which reduce adsorptive particle efficiency and consequently higher breakthrough concentration profiles. Comparison between experiments and simulations show good agreement. Improved biochar performance can be achieved by maintaining particle size uniformity alongside high adsorption capacity and adsorption rates appropriate to the rainfall intensity.

Integrating Nature-Based Solutions for Increased Resilience to Urban Flooding in the Climate Change Context

As climate change intensifies with more frequent and severe flood events, urban areas face increasing challenges to protect population wellbeing. Amid urban development challenges, political uncertainty, and socioeconomic pressures, finding sustainable solutions to enhance urban resilience has become urgent and complex. This article explores the limitations of traditional drainage systems in an urban zone of Bucharest, Romania, and the integration of nature-based solutions for flood mitigation. We compare the existing situation with those simulated in a climate change scenario before and after implementing green solutions. The imperviousness of parking lots was set at 60%, that of green roofs at 65%, and that of parking lots at 85%. A hydraulic model was used for this purpose. The results demonstrate that the current stormwater systems struggle to meet the demands of increasing rainfall intensity and highlight how sustainable strategies can effectively address extreme weather challenges while contributing to the restoration of natural environments within the city. In the case of using ‘gray’ solutions, only 10–20% of the area affected by floods is reduced. In comparison, a combination of gray and green infrastructure achieved an average reduction in peak water levels of 0.76 m.

Effect of Green Roofs on the Thermal Environment of Prototype Broiler Houses

The management of thermal environments in animal production facilities presents significant challenges, requiring continuous adjustments to meet animals’ physiological needs. This study evaluated the effects of green roofs on the thermal environment and comfort indices in small-scale poultry house prototypes, comparing facilities with and without green roof installations. The research tested various roof types (ceramic, fiber cement, and metal) combined with emerald grass (Zoysia japonica) green roof systems. Parameters measured included air temperature, relative humidity, internal roof surface temperature, Temperature and Humidity Index (THI), Black Globe Humidity Index (BGHI), Human Comfort Index (HCI), and Thermal Radiation Load (TRL) under both open and closed conditions. Results showed that green roofs reduced indoor air temperature by up to 2.4 °C in open prototypes and 10.6 °C in closed prototypes during peak heat periods. In combinations using green roofs with fiber cement tiles, internal roof surface temperature decreased by 24.0 °C in open prototypes and 27.0 °C in closed configurations. The implementation of green roofs resulted in THI reductions of 2.3 and 8.1 units in open and closed prototypes, respectively, BGHI decreases of 2.8 and 11.3 units, and TRL reductions of 21.0 W/m2 and 74.0 W/m2. HCI measurements confirmed improved thermal comfort conditions with green roof installations in both settings. This study concludes that green roofs effectively enhance the thermal environment by reducing bioclimatic indices during hot periods while maintaining stable conditions during cooler weather, thereby improving overall thermal comfort in animal facilities.

Optimizing plant species composition of green roofs for ecological functionality and biodiversity conservation

Green roofs provide vital functions within the urban ecosystem, from supporting biodiversity, to sustainable climate-positive ESS provisioning. However, how plant communities should best be designed to reach these objectives, and how specific green roof systems vary in their capacity to support these functions is not well understood. Here we compiled data on plant traits and plant–insect interaction networks of a regional calcareous grassland species pool to explore how designed plant communities could be optimised to contribute to ecological functionality for predefined green roof solutions. Five distinct systems with practical functionality and physical constraints were designed, plant communities modelled using object-based optimization algorithms and evaluated using five ecological functionality metrics (incl. phylogenetic and structural diversity). Our system plant communities supported a range of plant–insect interactions on green roofs, but not all species were equally beneficial, resulting in wide-ranging essentiality and redundancy in ecological processes. Floral traits were not predictive of pollinator preferences, but phylogeny was observed to govern the preferences. Large differences in ecological functionality can be expected between green roofs depending on system design and the extent of the plant community composition. Multifunctionality covariance diverged between systems, suggesting that ecological functionality is not inherently universal but dependent on structural limitations and species pool interactions. We conclude that informed system design has a potential to simultaneously support ecosystem services and urban biodiversity conservation by optimising green roof plant communities to provide landscape resources for pollinating insects and herbivores.

Energy Performance Assessment on Vertical Greening Systems with Green Roof in Hot Summer and Cold Winter Regions Based on Long-term Experimental Data

The integration of vertical greening systems and green roofs with buildings is currently a popular urban development approach aimed at mitigating the urban heat island effect and promoting sustainable development. However, most existing studies on vertical greening systems and green roofs are based on short-term experimental results, which might not reflect their overall performance. Thus, this paper aims at evaluating the energy performance of vertical greening systems and green roofs in a hot summer and cold winter region in China over a three-year period. Although energy-saving was found in summer, occasionally increases in energy demand occurred in winter. It confirms the need for long-term experiments to avoid contingency. The energy saving rate of vertical greening systems and green roofs was approximately 27.49%-42.48% (monthly) or 28.89%-34.02% (quarterly) during the cooling period (33.84% on average), and approximately -7.42%-13.79% (monthly) or -1.19%-6.58% (quarterly) during the heating period (3.6% on average). The impact of climatic conditions on energy saving rate was evaluated. It was found that solar radiation intensity is the most important factor, followed by the outdoor air temperature and relative humidity. This paper provides an insight on the long-term energy-saving benefits of vertical greening systems and green roofs in hot summer and cold winter regions and the correlation between climatic conditions and energy saving rate.

The Impact of Building Material Modeling on Enhancing Building Sustainability (Energy Efficiency): A Case Study of a Residential Building in Basilia

This research aims to study the impact of building materials modeling on enhancing building sustainability through a case study of a residential building within the Basilia City planning scheme in Damascus, which is being transformed into a sustainable area using sustainable design techniques. The study is based on analyzing plot EA-189 in the Kfar Sousseh area by evaluating the thermal efficiency of the proposed building materials and comparing them with other materials using the Insight Solar tool in Autodesk Revit.The study involves analyzing three scenarios using different building materials: (1) Concrete blocks with air insulation and a bituminous insulated roof, (2) Brick with fiberglass insulation and a green roof, (3) A mix of brick and concrete blocks on different facades and a green roof. The results show that the second scenario provides the highest energy efficiency and best indoor air quality, despite its higher cost. The third scenario, which combines brick and concrete blocks, offers a balance between energy efficiency and cost, making it the optimal choice for future construction projects. The study demonstrates that building information modeling (BIM) enhances the effectiveness of sustainable design strategies and contributes to improved energy performance and environmental comfort of buildings.

Digital twins for green roofs and facade inspection using drones and multi-modal foundation models

Green roofs and facades are a nature-based way to improve the climate of buildings. However, they also add additional maintenance effort for keeping the plants healthy. We propose a novel automated digital twin approach to monitor the health of the plants using a combination of drones with Foundation Models to monitor and analyze the health of the plants. The process consists of three main components, a drone system for recording real-time data in an automated manner for different heights, a digital twin for storing and controlling the data, and a Multi-modal Foundation model (MMFM) for diagnosis of health issues and generating recommendations for solving the issues. This allows us to automatically identify and mitigate health issues of the plants and improve the maintenance of the miniature ecosystems of green roofs and facades to address climate change risk and the shortage of skilled workers.

Comparative experimental study on the thermal and energy performance of photovoltaic and green roofs in hot-humid climates

Comparative experimental study on the thermal and energy performance of photovoltaic and green roofs in hot-humid climates

Global and regional estimation and evaluation of suitable roof area for solar and green roof applications

Global and regional estimation and evaluation of suitable roof area for solar and green roof applications

Reduction of atmospheric CO2 as affected by the type of photosynthesis of green roof plants

Reduction of atmospheric CO₂ as affected by the type of photosynthesis of green roof plants

Dataset on the impacts of sand and leaf litter on the hydrological performance of green roofs as surrogate for infiltration-based blue-green infrastructure (BGI)

Dataset on the impacts of sand and leaf litter on the hydrological performance of green roofs as surrogate for infiltration-based blue-green infrastructure (BGI)

Experimental and numerical analysis of thermal performance and energy consumption of ventilated green roof

Experimental and numerical analysis of thermal performance and energy consumption of ventilated green roof

Evaluating the potential of green roofs for greywater treatment

Evaluating the potential of green roofs for greywater treatment

THE ROLE OF URBAN AGRICULTURE IN FOOD SECURITY: A STUDY ON ENTREPRENEURIAL STRATEGIES FOR SUSTAINABLE FOOD SYSTEMS

Urban agriculture, encompassing farming methods within urban and peri-urban areas, has gained significant attention as a viable strategy to address food insecurity, environmental degradation, and urban poverty. This research explores the multifaceted importance of urban agriculture, highlighting its social, environmental, economic, and health benefits. It further examines entrepreneurial opportunities and strategies to foster sustainable food systems through innovative practices such as backyard cultivation, participatory gardens, green roofs, vertical farms, and tech-enabled marketplaces. The study underscores the critical role of urban agriculture in enhancing food security, promoting economic resilience, and fostering environmental sustainability, especially in rapidly urbanizing regions like Asia and Africa. By integrating policy advocacy, public-private partnerships, and climate-adaptive technologies, urban agriculture presents a scalable model for addressing urban challenges while encouraging entrepreneurship. The findings advocate for a holistic approach that combines technical assistance, community engagement, and policy support to harness the full potential of urban agriculture as a cornerstone of sustainable urban development.

Evaluating the Impact of Green Roofs on Urban Heat Island Effect and Stormwater Management

Due to rising urbanisation and climate change, urban areas are increasingly confronted with issues linked to the Urban Heat Island (UHI) effect and stormwater management. These challenges are becoming increasingly apparent. There has been a growing interest in green roofs as a sustainable building strategy due to the fact that they have the potential to alleviate these environmental problems. to what extent green roofs are beneficial in mitigating the urban heat island effect and in managing stormwater in urban environments. The research evaluates the thermal performance of green roofs by using a combination of field measurements, simulation models, and case studies. It also examines the impact that green roofs have on surface and ambient temperatures, as well as their capacity to retain and delay the discharge of rainwater. Green roofs have a substantial impact on lowering temperatures on rooftops, which in turn contributes to a reduction in the overall urban heat island effect. A further benefit of green roofs is that they improve stormwater management by soaking up rainwater, lowering peak flow rates, and delaying the discharge of runoff into urban drainage systems. In addition, the study underlines the fact that performance might vary depending on a variety of parameters, including the species of plant, the depth of the substrate, and the meteorological circumstances.

Mitigating Urban Heat Islands: The Role of Green Building Strategies

The combined effects of local warming brought on by urbanisation and global climate change are making urban heat a growing problem for many cities. Urban heat-related issues must be addressed immediately because these phenomena have substantial negative effects on the environment, the economy, society, and human health. Although buildings play a significant role in urban heat, they also offer opportunities for mitigation through the decarbonisation of the built environment. The building industry has acknowledged green buildings (GBs) as an innovative philosophy and practice. GBs have been suggested as a way to reduce the effects of urban heat islands (UHI) and other heat-related issues. The purpose of this study is to identify the most important architectural factors of green buildings that effectively reduce UHI. Using an extensive literature review methodology, the study identified eighteen important references following a thorough screening of more than 1400 preliminary studies. These sources concentrate on the ways that green buildings mitigate urban heat through different approaches, such as cutting carbon emissions, lessening the effects of artificial landscapes, and enhancing energy efficiency. The findings indicate that GBs significantly contribute to reducing the urban heat problem by lowering carbon emissions, minimising artificial landscapes, and promoting energy-efficient designs. This review provides a holistic analysis of the role of GBs in urban heat mitigation, aiming to inform future research in urban planning and green building development. This manuscript addresses a critical topic for the scientific and urban planning community. It highlights the role of green buildings (GBs) in mitigating the Urban Heat Island (UHI) effect, which is essential for combating climate change. The thorough literature review provides useful insights and identifies key strategies, such as green roofs and green infrastructure. It is valuable for researchers, policymakers, and practitioners in urban development and climate resilience.

Green Roof Retrofitting in Algeria Between Sustainability and Seismic Vulnerability

Installing green roofs in urban areas is a sustainable practice towards the ecological transition, they offer many advantages with regards to reducing energy consumption, mitigating the urban heat island effect, managing runoff ...etc. In order to propagate this technique, green roofs have to be installed on the top of existing buildings, which can increase their vulnerability during seismic events. The present paper aims to evaluate the impact of green roof retrofitting on the seismic performance of a collective housing in Algeria. To this end, the finite element method was adopted to investigate the seismic-related parameters according to the Algerian seismic regulations. The studied reinforced concrete building is located in the district of Constantine (northern east of Algeria). It was found that the presence of concrete walls, recommended by the Algerian seismic regulations, increases the rigidity of the building, which reflects positively on the building’s natural period and displacements. As for the stress-related parameters, the reduced normal force does not increase much; however, a significant increase in the shear forces at the base due to green roof implementation was observed. It was also found that adding a green roof contributes more to the stabilizing moment than to the overturning one during an earthquake event. Hence, in the studied context, the presence of load-bearing concrete walls offers certain positive effects on green roof installation with regard to the seismic performance. Nevertheless, a thorough seismic investigation should be performed before installing green roofs on the top of existing collective housing in Algeria.

Mitigating the Effects of Low-Impact Development on Waterlogging and Non-Point Pollution Under Different Confluence Relationships

Intensifying urbanization and climate change have highlighted the growing role of low-impact development (LID) practices in urban rainwater management systems. However, there is still room for improvement to optimally deploy LID practices, especially under different confluence relationships. In this study, 36 scenarios were designed based on different rainfall conditions, LID practices, confluence relationships, and locations, which were analyzed using hybrid hydraulic and water quality modeling. The following key results were obtained: (1) Series II was the main confluence path in the study area. The greenbelt occupied a large share; accordingly, the control of waterlogging and non-point source pollution in series II was better in the designed rainfall scenarios. (2) In the designed rainfall scenarios, series I had the best mitigation effect on waterlogging and non-point source pollution, with 24.5%, 16.4%, and 15.2% lower values than those of the series II and Parallel scenarios. There were no significant differences among the three confluence relationships under extreme rainfall. (3) Among the different LID practices, bioretention cells contributed to the maximum reduction in pollution (29.91%). Green roofs and permeable pavement resulted in the maximum reductions in total runoff (27.99% and 22.94%, respectively), and permeable pavement also reduced pollution by 26.50%. These results suggest that the pavement at some waterlogging points should be replaced with permeable pavement to avoid the negative effects of future extreme rainfall.

Impact of Green Roofs and Walls on the Thermal Environment of Pedestrian Heights in Urban Villages

(1) Background: Urban villages in Guangzhou are high-density communities with challenging outdoor thermal environments, which significantly impact residents’ thermal comfort. Addressing these issues is crucial for improving the quality of life and mitigating heat stress in such environments. (2) Methods: This study utilized a validated ENVI-met microclimate model to explore the synergistic cooling effects of roof greening and facade greening. Three greening types—total greening, facade greening, and roof greening—were analyzed for their impacts on air temperature, mean radiant temperature, and physiologically equivalent temperature (PET) at a pedestrian height of 1.5 m under varying green coverage scenarios. (3) Results: The findings showed that total greening exhibited the greatest cooling potential, especially under high coverage (≥50%), reducing PET by approximately 2.5 °C, from 53.5 °C to 51.0 °C, during midday, and shifting the heat stress level from “extreme heat stress” to “strong heat stress”. Facade greening reduced PET by about 1.5 °C, while roof greening had a limited effect, reducing PET by 1.0 °C. Furthermore, under coverage exceeding 75%, total greening achieved maximum reductions of 3.0 °C in mean radiant temperature and 1.2 °C in air temperature. (4) Conclusions: This study provides scientific evidence supporting total greening as the most effective strategy for mitigating heat stress and improving thermal comfort in high-density urban villages, offering practical insights for optimizing green infrastructure.