Rohinton Emmanuel
@gcu.ac.uk
Professor, Dept of Civil Engineering, School of Engineering, Computing and Built Environment
Glasgow Caledonian University
RESEARCH, TEACHING, or OTHER INTERESTS
Building and Construction, Atmospheric Science, Urban Studies, Architecture
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Ankur Negi, Rohinton Emmanuel, and Eeva Aarrevaara
MDPI AG
With global climate change causing temperature increases, even cooler regions like Finland are facing increasing heat risks. The city of Lahti is expected to experience a higher-than-average temperature increase, making heat risk mitigation essential. This study aims to assess present and future heat risks in Lahti using exposure and social vulnerability indicators to identify heat risk hotspots and provide strategies for mitigation within the city’s urban planning framework. The method utilizes a combination of Land Surface Temperature (LST) data (2014–2024), climate projections, and microclimate analysis to identify heat risk in the city. Geographic Information Systems (GIS) and ENVI-met modeling were employed to assess the relationship between land surface temperatures (LST), urban structure, and green infrastructure. Risk assessments were conducted using social and environmental vulnerability indicators, and future projections were based on a combined SSP2-4.5 scenario. The results show a significant increase in high-risk areas by 2040, rising from 9.79% to 23.65% of Lahti’s core urban area. Although the current urban planning framework of the city (Masterplan 2035) is effective in terms of maintaining exposure levels, the continued increase in projected air temperatures, as modeled based on outputs of the EC-Earth3-veg GCM, remains a concern. Microclimate modeling confirmed that urban greenery significantly reduces heat stress and improves thermal comfort. To address future heat risks, Lahti must integrate more green infrastructure into its urban design and identify seasonal heat mitigation methodologies. Additionally, the findings emphasize the need for adaptive planning strategies to mitigate rising temperatures and ensure urban resilience.
Malithie Vidanapathirana, Narein Perera, Rohinton Emmanuel, and Shaleeni Coorey
Emerald
PurposeAir pollution and air quality are key environmental factors that impact an investor’s willingness to pay (WTP) and are negatively correlated. Hedonic pricing quantifies the relationship between air pollutants and property values but is a backward-looking tool. Similarly, limited research links investment potential to urban planning and air pollution. This research aims to predict variation in investor WTP due to air pollution concentrations within a high-dense high-rise building cluster.Design/methodology/approachPossible building configurations of Port City, Colombo, were modelled using Ansys Fluent. While maintaining the same Floor Area Ratio (FAR), building heights and volumes, the density of towers is changed by introducing wind corridors to enable pollutant dispersion. A trace pollutant is used as a comparative study to determine the effect of each building form on pollution concentration and potential WTP.FindingsThe introduction of wind corridors along the ambient wind direction increased building porosity, positively affecting WTP overall. Wind corridors perpendicular to the ambient wind reduced porosity, which reduced dispersion at upper levels, negatively affecting WTP.Research limitations/implicationsWTP is site-specific, and due to limited data for property values and volatility, the study was limited to a comparison study.Practical implicationsVarying building configurations affect pollutant dispersion at different heights. The findings of the study can refine investments based on air quality and natural ventilation requirements.Originality/valueThis paper fulfils a need to determine investment potential and air quality.
Teodoro Semeraro, Antonio Calisi, Jian Hang, Rohinton Emmanuel, and Riccardo Buccolieri
MDPI AG
Nature-based Solutions (NbSs) play a pivotal role in mitigating the impact of microclimates on human well-being. The effectiveness of NbSs is contingent upon the synergy between natural capital, defined by the ecological structure and functions of the ecosystem, and human-derived capital, encompassing the economic investments required for implementation. This study introduces a decision-making framework designed to evaluate the impact of NbSs and advocate for optimal solutions for human health at the local scale, amalgamating ecological and economic assessments. Physiological Equivalent Temperature (PET) was chosen as a key urban parameter to assess the efficacy of NbSs in mitigating urban microclimates and enhancing human health. The PET analysis was conducted using ENVI-met 5.0.3 software across diverse urban scenarios in Gallipoli city, Italy. Integrated with a cost–benefit analysis of NbSs considering various investment scenarios, the study aimed to identify the most effective solution. Results indicated positive effects of NbSs in open spaces and around building blocks where the PET levels remained below 30 °C. Conversely, scenarios without NbSs exhibited PETs exceeding 40 °C, with peaks of 50 °C, posing potential risks to human health. Considering the social and economic benefits associated with PET mitigation, the cost–benefit analysis suggests that implementing NbSs using a mix of young and mature plants in the initial phase is advantageous compared to using only young plants. Thus, in establishing NbSs, it is crucial to consider not only the quantity of vegetation but also the strategic timing of implementation. In conclusion, our work offers an innovative framework that combines ecological and economic perspectives, providing valuable insights for decision-makers in urban planning and promoting the practical application of NbSs for enhanced human well-being.
S.B. Mickovski, A. Gonzalez-Ollauri, A. Sorolla, A. Löchner, and R. Emmanuel
Elsevier BV
Shifana Simath, Rohinton Emmanuel, and Eeva Aarrevaara
MDPI AG
Cities face increasing heat risk due to global and local warming, and the risk is greater in the developing world. South Asia, in particular, faces increasing urban climate risk, but the translation of urban climate knowledge into sustainable climate-sensitive planning is weak. In this paper, we report on our conversations with experts from the Sri Lankan urban planning community on the barriers to and opportunities for urban climate mitigation action. We uncover six themes (insights, integrate, specify, exhort, commitment, and continuity) that best exemplify both the barriers to and opportunities for enhancing heat risk resilience in this primate city. We then map a set of agencies and actors that need to be involved in any holistic risk resilience plan and draw wider lessons to sustainably manage the urgent practical gaps in heat health planning.
Lewis Blunn, Xiaoxiong Xie, Sue Grimmond, Zhiwen Luo, Ting Sun, Narein Perera, Rangajeewa Ratnayake, and Rohinton Emmanuel
Elsevier BV
Natasha Picone, Antonio Esposito, Rohinton Emmanuel, and Riccardo Buccolieri
MDPI AG
This study delves into Green Infrastructure (GI) planning in Brindisi, Italy, evaluating its influence on urban air quality and thermal comfort. Employing an LCZ-centered Geographic Information System (GIS)-based classification protocol, the prevalence of LCZ 6 (Open low-rise) and LCZ 2 (Compact mid-rise) is highlighted. Despite generally low PM10 levels in Brindisi, intermittent NOx spikes surpassing WHO and EU standards pose health risks. Within LCZ 2, diverse GI interventions (green walls, hedges, trees) were tested, with green walls emerging as the most effective, albeit falling short of expectations, while trees exhibited adverse air quality impacts. LCZ 6 demonstrated enhanced air quality attributed to wind patterns, GI, and urban canyon improvements. Thermal comfort analysis consistently revealed positive outcomes across various GI types, reducing discomfort by a minimum of 10%. The study emphasized GI’s favorable comfort impact on sidewalks but cautioned against trees in street canyons with aspect ratios exceeding 0.7, heightening pollutant levels and implying increased exposure risks. Conversely, street canyons with lower aspect ratios displayed variable conditions influenced by prevailing regional wind patterns. In conclusion, the integrated assessment of LCZ and GI holds promise for informed urban planning, guiding decisions that prioritize healthier, more sustainable cities. This underscores the crucial need to balance GI strategies for optimal urban development, aligning with the overarching goal of promoting urban well-being and sustainability.
Malithie Vidanapathirana, Narein Perera, Rohinton Emmanuel, and Shaleeni Coorey
Springer Science and Business Media LLC
O. Ananyeva and R. Emmanuel
Elsevier BV
Teodoro Semeraro, Elisa Gatto, Luigi De Bellis, Andrea Luvisi, Rohinton Emmanuel, and Riccardo Buccolieri
Elsevier BV
Alejandro Gonzalez-Ollauri, Slobodan B. Mickovski, Carl C. Anderson, Sisay Debele, Rohinton Emmanuel, Prashant Kumar, Michael Loupis, Joy Ommer, Jan Pfeiffer, Depy Panga,et al.
Elsevier BV
Rohinton Emmanuel, Mushfik Jalal, Samson Ogunfuyi, Nusrath Maharoof, Megi Zala, Narein Perera, and Rangajeewa Ratnayake
MDPI AG
Global and urban-induced local warming lead to increasing heat risk in cities. The rapid increase in urban population, weak infrastructure, poverty, as well as an ageing population, make the risk more acute in developing cities. However, heat risk is not uniformly distributed and a detailed exploration of the link between urban characteristics and local variations in heat risk is needed to aid targeted mitigation. In this paper, we demonstrate a fine-grained heat risk map using existing data combined with expert opinion in a humid tropical city (Colombo, Sri Lanka) with the objective of highlighting the relative heat risk as a function of physical and socioeconomic conditions across the city. We then simulate the effects of shading and greening on the ‘high’ heat risk areas, and greening on the ‘low’ heat risk areas, to show that a combined approach will be needed to reduce risk at ‘high’ risk areas. In ‘low’ risk areas, maintaining the green cover is crucial to heat risk reduction. The paper, thus, establishes a protocol for detailed heat risk mapping with existing data and points to the differing importance of shading and greening in different parts of the city, thus, showing where, and to what extent, mitigation actions could be beneficial.
M. Vidanapathirana, , N. Perera, R. Emmanuel, S. Coorey, , and
Ceylon Institute of Builders - Sri Lanka
A rapid increase in high-rise building clusters within developing cities has led to mounting environmental and climatic issues. This is especially highlighted in Asian cities where extreme tropical climates are accentuated by ad-hoc developments, that in turn create unfavourable urban environments. Traffic emissions and air pollution, directly and indirectly, effect the Urban Heat Island (UHI) factor. Studies show that urban ventilation is a key mechanism to ameliorate UHI, reduce pollution stagnation, improve air quality, and reduce dependence on energy-consuming systems, thereby enhancing future sustainability. A research gap on the effect of the morphology of high-rise towers, and tower and podium forms as clusters on air pollution dispersion was identified. A high-rise cluster in the proposed Port City in Colombo, Sri Lanka was identified, and possible building forms were designed based on guidelines given by the local authority. Simplified three-dimensional building clusters were simulated using Ansys Fluent and a RANS k-epsilon turbulence model. Results suggest the addition of a podium has minimal impact on pollution dispersion when compared with only a tower form. Block podiums were found to concentrate pollution within the podium height, while tiered podiums pushed street pollution upwards along the face of a podium. However, more uniform dispersion was seen in tiered podiums, reducing overall pollution concentrations within the study area. Overall, as per requirement and context, it is highlighted that podium forms can be designed to create better-ventilated urban spaces with good air quality, within a high-rise high-dense environment.
Hadjira Sakhri, Yassine Bada, and Rohinton Emmanuel
Springer Science and Business Media LLC
Saeedeh Nasehi, Ahmadreza Yavari, Esmail Salehi, and Rohinton Emmanuel
Elsevier BV
Shifana Simath and Rohinton Emmanuel
Springer Science and Business Media LLC
AbstractUrban dwellers experience overheating due to both global and urban warming. The rapid urbanisation, especially in hot, humid cities, lead to greater exposure to heat risk, both due to increasing urban populations as well as overheating due to global/urban warming. However, a nation-wide exploration of thermal comfort trends, especially in the hot, humid tropics, remains relatively unexplored. In this paper, we explore the recent historical trends (1991–2020) in outdoor thermal comfort across the entire island of Sri Lanka and evaluate the likely effects of known urban climate mitigation strategies — shade and vegetative cover. We find that ‘very strong heat stress’ is moving towards ‘extreme heat stress’ that was barely registered in 1990s and is now common across two-thirds of the landmass of Sri Lanka in the hottest month (April). Even in the coolest month (January), ‘moderate heat stress’ unknown in the 1990s is now becoming a common trend across the most densely populated parts of the country. High shading and vegetation could reduce heat stress, even in the hottest month, but its utility will diminish as the warming continues in future. As such, policies to reduce global warming needs to be urgently pursued while simultaneously adapting to urban warming in Sri Lanka.
Teodoro Semeraro, Aurelia Scarano, Angelo Santino, Rohinton Emmanuel, and Marcello Lenucci
Elsevier BV
Jeetendra Sahani, Prashant Kumar, Sisay Debele, and Rohinton Emmanuel
Elsevier BV
Hanna Meiria Naomi Stepani and Rohinton Emmanuel
MDPI AG
Green infrastructure is well recognized as a key urban climate mitigation strategy. In line with this, and following a central government decree, Jakarta Municipal Government has created a green infrastructure target of 30% underpinned by a green space weighting factor. This study questions the efficacy of such a “universal” target setting from the point of view of outdoor thermal comfort and demonstrates the basis for an alternative approach. Based on a “new’ green factor developed from a systematic analysis of the literature, thermal comfort simulations of representative local climate zones (LCZ) show that improvements in current green space policy are possible. We enumerate a rational basis for specifying green space targets per local area based on contextual realities as captured by the LCZ approach. Such a nuanced approach to mitigate the human comfort consequences of inadvertent urban growth is not only more contextually appropriate but also enhances the feasibility of achieving the intended goal of urban greening in Jakarta.
Alejandro Gonzalez-Ollauri, Karen Munro, Slobodan B. Mickovski, Craig S. Thomson, and Rohinton Emmanuel
Frontiers Media SA
The idea of nature providing solutions to societal challenges is relatively easy to understand by the layperson. Nature-based solutions (NBS) against landslides and erosion mostly comprise plant-based interventions in which the reinforcement of slopes provided by vegetation plays a crucial role in natural hazard prevention and mitigation, and in the provision of multiple socio-ecological benefits. However, the full potential of NBS against landslides and erosion is not realised yet because a strong evidence base on their multi-functional performance is lacking, hindering the operational rigour of NBS practice and science. This knowledge gap can be addressed through the definition of repositories of key performance indicators (KPIs) and metrics, which should stem from holistic frameworks facilitating the multi-functional assessment of NBS. Herein, we propose the ‘rocket framework’ to promote the uptake of NBS against landslides and erosion through the provision of a comprehensive set of indicators which, through their appropriate selection and measurement, can contribute to build a robust evidence base on NBS performance. The ‘rocket framework’ is holistic, reproducible, dynamic, versatile, and flexible in helping define metrics for NBS actions against landslides and erosion along the NBS project timeline. The framework, resultant from an iterative research approach applied in a real-world environment, follows a hierarchical approach to deal with multiple scales and environmental contexts, and to integrate environmental, eco-engineering, and socio-ecological domains, thus establishing a balance between monitoring the engineering performance of NBS actions against landslides and erosion, and the wider provision of ecosystem functions and services. Using a case study, and following the principles of credibility, salience, legitimacy, and feasibility, we illustrate herein how the ‘rocket framework’ can be effectively employed to define a repository with over 40 performance indicators for monitoring NBS against landslides and erosion, and with over 60 metrics for establishing the context and baseline upon which the NBS are built and encourage their reproduction and upscaling.
Teodoro Semeraro, Riccardo Buccolieri, Marzia Vergine, Luigi De Bellis, Andrea Luvisi, Rohinton Emmanuel, and Norbert Marwan
MDPI AG
Agricultural activity replaces natural vegetation with cultivated land and it is a major cause of local and global climate change. Highly specialized agricultural production leads to extensive monoculture farming with a low biodiversity that may cause low landscape resilience. This is the case on the Salento peninsula, in the Apulia Region of Italy, where the Xylella fastidiosa bacterium has caused the mass destruction of olive trees, many of them in monumental groves. The historical land cover that characterized the landscape is currently in a transition phase and can strongly affect climate conditions. This study aims to analyze how the destruction of olive groves by X. fastidiosa affects local climate change. Land surface temperature (LST) data detected by Landsat 8 and MODIS satellites are used as a proxies for microclimate mitigation ecosystem services linked to the evolution of the land cover. Moreover, recurrence quantification analysis was applied to the study of LST evolution. The results showed that olive groves are the least capable forest type for mitigating LST, but they are more capable than farmland, above all in the summer when the air temperature is the highest. The differences in the average LST from 2014 to 2020 between olive groves and farmland ranges from 2.8 °C to 0.8 °C. Furthermore, the recurrence analysis showed that X. fastidiosa was rapidly changing the LST of the olive groves into values to those of farmland, with a difference in LST reduced to less than a third from the time when the bacterium was identified in Apulia six years ago. The change generated by X. fastidiosa started in 2009 and showed more or less constant behavior after 2010 without substantial variation; therefore, this can serve as the index of a static situation, which can indicate non-recovery or non-transformation of the dying olive groves. Failure to restore the initial environmental conditions can be connected with the slow progress of the uprooting and replacing infected plants, probably due to attempts to save the historic aspect of the landscape by looking for solutions that avoid uprooting the diseased plants. This suggests that social-ecological systems have to be more responsive to phytosanitary epidemics and adapt to ecological processes, which cannot always be easily controlled, to produce more resilient landscapes and avoid unwanted transformations.
Elisa Gatto, Fabio Ippolito, Gennaro Rispoli, Oliver Savio Carlo, Jose Luis Santiago, Eeva Aarrevaara, Rohinton Emmanuel, and Riccardo Buccolieri
MDPI AG
This study analyses the interactions and impacts between multiple factors i.e., urban greening, building layout, and meteorological conditions that characterise the urban microclimate and thermal comfort in the urban environment. The focus was on two neighbourhoods of Lecce city (southern Italy) characterised through field campaigns and modelling simulations on a typical hot summer day. Field campaigns were performed to collect greening, building geometry, and microclimate data, which were employed in numerical simulations of several greening scenarios using the Computational Fluid Dynamics-based and microclimate model ENVI-met. Results show that, on a typical summer day, trees may lead to an average daily decrease of air temperature by up to 1.00 °C and an improvement of thermal comfort in terms of Mean Radiant Temperature (MRT) by up to 5.53 °C and Predicted Mean Vote (PMV) by up to 0.53. This decrease is more evident when the urban greening (in terms of green surfaces and trees) is increased by 1266 m2 in the first neighbourhood and 1988 m2 in the second one, with respect to the current scenario, proving that shading effect mainly contributes to improving the urban microclimate during daytime. On the contrary, the trapping effect of heat, stored by the surfaces during the day and released during the evening, induces an increase of the spatially averaged MRT by up to 2 °C during the evenings and a slight deterioration of thermal comfort, but only locally where the concentration of high LAD trees is higher. This study contributes to a better understanding of the ecosystem services provided by greening with regard to microclimate and thermal comfort within an urban environment for several hours of the day. It adds knowledge about the role of green areas in a Mediterranean city, an important hot spot of climate change, and thus it can be a guide for important urban regeneration plans.
J. Ahmad, H. Larijani, R. Emmanuel, M. Mannion, and A. Javed
Emerald
Buildings use approximately 40% of global energy and are responsible for almost a third of the worldwide greenhouse gas emissions. They also utilise about 60% of the world’s electricity. In the last decade, stringent building regulations have led to significant improvements in the quality of the thermal characteristics of many building envelopes. However, similar considerations have not been paid to the number and activities of occupants in a building, which play an increasingly important role in energy consumption, optimisation processes, and indoor air quality. More than 50% of the energy consumption could be saved in Demand Controlled Ventilation (DCV) if accurate information about the number of occupants is readily available (Mysen et al., 2005). But due to privacy concerns, designing a precise occupancy sensing/counting system is a highly challenging task. While several studies count the number of occupants in rooms/zones for the optimisation of energy consumption, insufficient information is available on the comparison, analysis and pros and cons of these occupancy estimation techniques. This paper provides a review of occupancy measurement techniques and also discusses research trends and challenges. Additionally, a novel privacy preserved occupancy monitoring solution is also proposed in this paper. Security analyses of the proposed scheme reveal that the new occupancy monitoring system is privacy preserved compared to other traditional schemes.
Rohinton Emmanuel
Ubiquity Press, Ltd.
A summary is presented of current knowledge and key considerations in urban climate mitigation that have a bearing on planning practice in temperate climates. Urban climate is the intended or unintended local climate consequence of planning decisions at the street, neighbourhood and even city scales. Such local climate change adds to the changing global climate, where it both interacts with as well as exacerbates the human, energy, built environment and urban consequences of climate change. Although a relatively new field of study, knowledge about urban climate has sufficiently grown in recent decades to be of practical value to decision-making in the design and planning arenas. The climatic, wellbeing and carbon impacts of urban climate change are summarised along with best practices in mitigation and their relative merits. Key action points involve mapping heat vulnerability as well as enhancing heat resilience. It is hoped this briefing note will raise awareness of the wide range of issues involved in responding to the urban climate anomaly, whether in planning new districts or infilling existing ones.