The urban heat island effect, its causes, and mitigation, with reference to the thermal properties of asphalt concrete.

Green roofs have been proposed as an efficient and practical tool to combat urbanisation in many countries. This review paper focuses on various benefits associated with green roofs and research efforts made till date to promote green roofs. Through systematic comparison of literature, this review also emphasises knowledge gap that prevail in green roof technology and highlight the need for local research to install green roofs in developing and under-developed countries. Considering that growth substrate, vegetation and drainage layer determine the success of green roof, efforts were made to consolidate desirable characteristics for each of these components and suggests methodology to construct practical green roofs. This critical review also explores limitations associated with green roofs and recommend strategies to overcome. Apart from stand-alone green roofs, there is a huge scope for hybrid green roof systems with other established techniques, which are presented and discussed. Recommendations for future study are also provided.

Green roofs: A critical review on the role of components, benefits, limitations and trends

Research on the green roof has been raised expeditiously over the past decade. Green roof have been proposed as the sustainable practice to mitigate the adverse effects of urbanization. This review paper includes the history of the green roof, green roof components and multiple benefits (environmental, social and economical) associated with the green roof technology. This paper also emphasizes how the green roof works in different areas, their performance in reducing the stormwater and energy costs, improving air and ecological performance. The benefits of green roof show that it plays an important role in making cities safe, sustainable and resilient to climate change. Therefore, many countries are giving incentives to the house owners for the application of green roof. However, initial high construction costs, high maintenance costs and roof leakage problems are the main challenges associated with the application of green roofs. These challenges can be overcome with the of new cost effective green roof design that can work more effectively and efficiently in any area. Advanced modification and trends of green roof application are also included in this paper. The paper also highlights the research challenges and research gap of the green roof. At the end, for the better performance of the green roofs, some of the recommendations are also provided.

Green roof benefits, opportunities and challenges – A review

The Urban Heat Island (UHI) is a well-studied phenomenon, whereby urban areas are generally warmer than surrounding suburban and rural areas. The most direct effect on health from the UHI is due to heat risk, which is exacerbated in urban areas, particularly during heat waves. However, there may be health benefits from warming during colder months. This review highlights recent attempts to quantitatively estimate the health impacts of the UHI and estimations of the health benefits of UHI mitigation measures. Climate change, increasing urbanisation and an ageing population in much of the world, is likely to increase the risks to health from the UHI, particularly from heat exposure. Studies have shown increased health risks in urban populations compared with rural or suburban populations in hot weather and a disproportionate impact on more vulnerable social groups. Estimations of the impacts of various mitigation techniques suggest that a range of measures could reduce health impacts from heat and bring other benefits to health and wellbeing. The impact of the UHI on heat-related health is significant, although often overlooked, particularly when considering future impacts associated with climate change. Multiple factors should be considered when designing mitigation measures in urban environments in order to maximise health benefits and avoid unintended negative effects.

The Urban Heat Island: Implications for Health in a Changing Environment.

Between 60% and 80% of global energy is consumed in urban areas and given the projected increase in world׳s urban population, this share is expected to further increase in the future. Continuity of energy supply in cities is affected by climate change and a growing array of other threats such as cyber attacks, terrorism, technical deficiencies, and market volatility. Determined efforts, acknowledging the interactions and interlinkages between energy and other sectors, are needed to avoid adverse consequences of disruption in energy supply. Resilience thinking is an approach to management of socio-ecological systems that aims to develop an integrated framework for bringing together the (often) fragmented, diverse research on disaster risk management. The literature on urban resilience is immense and still growing. This paper reviews literature related to energy resilience to develop a conceptual framework for assessing urban energy resilience, identify planning and design criteria that can be used for assessing urban energy resilience, and examine the relationship of these criteria with the underlying components of the conceptual framework. In the conceptual framework, it is proposed that in order to be resilient, urban energy system needs to be capable of “planning and preparing for”, “absorbing”, “recovering from”, and “adapting” to any adverse events that may happen in the future. Integrating these four abilities into the system would enable it to continuously address “availability”, “accessibility”, “affordability”, and “acceptability” as the four sustainability-related dimensions of energy. The paper explains different resilience principles associated with these abilities and sustainability dimensions. Also, different planning and design criteria were extracted from the literature and categorized into five themes: infrastructure; resources; land use, urban geometry and morphology; governance; and socio-demographic aspects and human behavior. Examination of the relationship of these criteria with the underlying components of the conceptual framework highlighted the complexity and multi-faceted nature of energy resilience. Exploration of the relevance of the identified criteria to climate change mitigation and adaptation revealed that most of the identified criteria can provide both mitigation and adaptation benefits.

Mostafa Razzaghmanesh

Papers

Introducing a water quality index for assessing water for irrigation purposes: A case study of the Ghezel Ozan River.

The role of green roofs in mitigating Urban Heat Island effects in the metropolitan area of Adelaide, South Australia

Water quality and quantity investigation of green roofs in a dry climate.

Impact of green roofs on stormwater quality in a South Australian urban environment

The hydrological behaviour of extensive and intensive green roofs in a dry climate.