Green Roofs: A Sustainable Solution To Urban Areas
About this Book
Urban rooftops covered with plants known as “green roofs” or “vegetative roofs” have been recently proposed as an efficient and practical tool to combat urbanization in many countries. Green roofs attracted intense research interest because of their unique benefits and recognition in various countries as a potential best management practice. This book briefly introduces the fundamentals and benefits of vegetative roofs. The advantages include (i) enhancement of air quality, (ii) decrease in consumption of energy for heating and cooling, (iv) noise reduction, (v) ecological preservation, (vi) attenuation of storm water runoff, and (vii) reduction of urban heat-island. However, most of these benefits are just theoretical assumptions, and fewer research efforts were performed to draw a certain conclusion. Hence, the present book explores limitations associated with green roofs and recommend strategies to overcome. Through systematic comparison of literature, this book also emphasizes knowledge gap that prevail in green roof technology and highlight the need for local research to popularize green roofs in developing and under-developed countries. To improve the quality of runoff, the book explores the possibility of exploring the sorption capacity of the substrate, as well as the phytoremediation potential of plants. Also, for the first time, various sorbents that can be used as additives in vegetative roof substrate, as well as practical plant species that can phytoextract contaminants in the substrate are highlighted. 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.
Chapter 1 introduces the readers to the impact of urbanization and importance of green
roofs in urban areas.
Chapter 2 explores the history of green roofs and status of green roofs in various countries. This chapter also highlights the importance of local research.
Chapter 3 presents the types of green roofs and their intrinsic characteristics. The factors discussed include cost, maintenance, plant selection, overall weight and substrate type.
Chapter 4 discusses benefits of green roofs in detail. The benefits highlighted include stormwater attenuation, thermal benefits, water quality enhancement, noise reduction, mitigate air pollution, green space in urban environment, recycled materials during construction, roof protection, enhance biodiversity and habitat for wildlife.
Chapter 5 reports various components that constitute green roof. Important components including vegetation, growth substrate, filter fabric, drainage layer, waterproofing layer and root barrier were discussed. In particular, various types and screening procedures to select growth substrate and vegetation are discussed.
Chapter 6 lists short-comings/constraints of green roofs. The factors discussed include maintenance, cost, runoff quality, importance of local research, green aspects, roof leakage, ultimate disposal and structural damage.
Chapter 7 explains new trends in green roof technology in recent years. Hybrid photovoltaic-green roof, green roof-grey water system and portable green roof modules are discussed.
Chapter 8 discusses scope and future directions of green roof technology.