Download or read book Evaluating Storm Water Runoff of Green Roofs with Varying Growth Medium and Species Composition written by Erin Hilligoss-Volkmann and published by . This book was released on 2011 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plant Selection Community Structure Ecophysiology and Stormwater Mitigation on Green Roofs in the Southeastern U S written by Julie Guckenberger Price and published by . This book was released on 2013 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Green roofs offer the opportunity to transform impervious surfaces into multifunctional constructed ecosystems. Plant selection for green roofs is often limited to drought-tolerant succulent species, but more diverse assemblages enhance habitat and biodiversity in urban areas and have the potential to improve green roof performance. Nineteen taxa were evaluated under irrigated and non-irrigated conditions over three growing seasons. Individual taxa were evaluated for survival and amount and mechanism of colonization, and the effect of irrigation on plant community structure and vegetation coverage was examined. Only succulent species survived under non-irrigated conditions. Irrigated plots had more taxa, higher diversity index, less bare ground, and more individuals than non-irrigated plots. Irrigation is recommended on extensive green roofs to increase the palette for plant selection by protecting against plant mortality due to drought and extreme soil temperatures. To provide an estimate of the capacity of a photosynthetically diverse selection of plants to transpire water, maintain photosynthetic functionality, and mitigate stormwater in green roof systems, three species were selected for evaluation: Bouteloua curtipendula, a C4 bunchgrass; Phlox bifida, a C3 forb; and S. album 'France', a facultative CAM succulent. Gas exchange was measured over a cycle of drying down and rehydration during spring, summer, and fall experimental seasons. B. curtipendula had higher rates of net carbon assimilation (An) and stomatal conductance (gs) than P. bifida and S. album, particularly in the summer season, and recovered rapidly following rehydration. In general, An and gs of S. album were low. In the southeastern U.S., B. curtipendula and P. bifida could be utilized on a green roof with limited irrigation to gain evapotranspirative benefits in spring, summer, and fall. Sedum album was found to contribute little transpiration, but could be included for winter cover to improve soil stabilization and increase morphological diversity. While differences in stormwater mitigation among the different species could not be discerned, each of the species reduced the total volume, delayed the start, and extended the duration of stormwater runoff compared with impervious roof surfaces.

Download or read book Green Roof Water Quality Impacts and Physicochemical Stability written by Grace Ella Harper and published by . This book was released on 2013 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Green roofs can provide environmental benefits and conserve energy; this research evaluated green roof stormwater management, nutrient loading, and erosion prevention for two green roof media. During a pilot study, the runoff quantity and composition from green roof material was evaluated continuously under field conditions for two different media, both tested under planted and unplanted conditions. Water quantity results show over a 40% reduction in runoff from just the growing media and over 60% reduction in runoff with established plants in green roof media over the eight month study. Previous studies have reported a "first flush" of excess nutrients but without evaluating the duration and intensity of this phenomenon throughout the first year of the roof's life. Total phosphorus at 30 mg/L and nitrogen concentrations above 60 mg/L were observed in green roof runoff initially, with concentrations decreasing over time to 5 and 10 mg/L, respectively. In addition, elevated total organic carbon concentrations were observed, with concentrations of 500 mg/L initially, decreasing to below ten percent of initial concentrations. Media type and age were the largest influences on carbon and nutrient concentrations. Understanding runoff nutrient kinetics can better aid in developing procedures to minimize nutrient runoff and predict nutrient loading more accurately. In testing physical stability, both wind tunnel testing and sampling of total suspended solids in runoff were performed. The green roof drainage and filter fabric systems proved effective at preventing water-based erosion, with median total suspended solids concentrations for both below 20 mg/L. Because wind erosion can occur, surface stabilizers (i.e. adhesives) are available to secure green roof media. Green roof adhesive and plant cover were evaluated through wind tunnel testing; both reduced wind scour down to one-tenth of observed scour without any cover, providing protection against wind erosion"--Abstract, page iv.

Download or read book Evaluation of the Quantity and Quality of Storm Water Runoff Released from Various Green Roof Systems written by Emily Woods and published by . This book was released on 2010 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Green Roof Ecosystems written by Richard K. Sutton and published by Springer. This book was released on 2015-06-04 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an up-to-date coverage of green (vegetated) roof research, design, and management from an ecosystem perspective. It reviews, explains, and poses questions about monitoring, substrate, living components and the abiotic, biotic and cultural aspects connecting green roofs to the fields of community, landscape and urban ecology. The work contains examples of green roof venues that demonstrate the focus, level of detail, and techniques needed to understand the structure, function, and impact of these novel ecosystems. Representing a seminal compilation of research and technical knowledge about green roof ecology and how functional attributes can be enhanced, it delves to explore the next wave of evolution in green technology and defines potential paths for technological advancement and research.

Download or read book Regeneration of the Built Environment from a Circular Economy Perspective written by Stefano Della Torre and published by Springer Nature. This book was released on 2019-01-01 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book explores the strategic importance and advantages of adopting multidisciplinary and multiscalar approaches of inquiry and intervention with respect to the built environment, based on principles of sustainability and circular economy strategies. A series of key challenges are considered in depth from a multidisciplinary perspective, spanning engineering, architecture, and regional and urban economics. These challenges include strategies to relaunch socioeconomic development through regenerative processes, the regeneration of urban spaces from the perspective of resilience, the development and deployment of innovative products and processes in the construction sector in order to comply more fully with the principles of sustainability and circularity, and the development of multiscale approaches to enhance the performance of both the existing building stock and new buildings. The book offers a rich selection of conceptual, empirical, methodological, technical, and case study/project-based research. It will be of value for all who have an interest in regeneration of the built environment from a circular economy perspective.

Download or read book Living Roofs in Integrated Urban Water Systems written by Daniel Roehr and published by Routledge. This book was released on 2015-03-05 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the infrastructure to manage storm water threats in cities becoming increasingly expensive to build or repair, the design community needs to look at alternative approaches. Living roofs present an opportunity to compliment ground-level storm water control measures, contributing to a holistic, integrated urban water management system. This book offers tools to plan and design living roofs, in the context of effectively mitigating storm water. Quantitative tools for engineering calculations and qualitative discussion of potential influences and interactions of the design team and assembly elements are addressed.

Download or read book The Mitigating Effect of Substrate Depth on Green Roof Stormwater Discharge written by Kwan-Lam Wong and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "The Mitigating Effect of Substrate Depth on Green Roof Stormwater Discharge" by Kwan-lam, Wong, 王韵琳, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Urbanization replaces once permeable surfaces with relatively impervious ones, thereby degrading the natural hydrologic cycle. Impervious surfaces intensify stormwater runoff in terms of overall mass and temporal response, especially under torrential rainfalls. Since such runoff could become massive in volume and concentrated in time, they place significant stress on the urban drainage system and increase the risks of combined sewage overflow and flooding, which could introduce a range of deleterious consequences to cities and surrounding natural habitats. In sustainable urban stormwater management like the Low Impact Development, green roof presents an on-site source-reduction measure that mimics the pre-development hydrologic functions of storing and gradually releasing precipitation. Green roof can retain and detain stormwater as well as delay and suppress peak discharge. However, green roof stormwater studies have largely been conducted in non-tropical regions of the world. Since green roof's quantitative hydrologic performance can be much influenced by local meteorological conditions, the degree to which such findings can be generalized to other climates, such as Hong Kong's humid subtropical regime, calls for investigation. Moreover, substrate depth has long been regarded as an influential factor in green roof stormwater retention, but two recent studies have provided contradictory results. The objectives of this study are: 1) To evaluate green roof stormwater mitigation performance and potentials in Hong Kong for the first time; 2) To investigate systematically the effect of substrate depth on quantitative hydrologic performance; 3) To identify factors that affect green roof performance; 4) To develop a holistic conceptualization of the various system water storage spaces within a green roof system, for a better understanding of their role in stormwater mitigation. Using small-scale (1.1 m2) raised green roof plots placed on an actual urban rooftop, the effect of 40 mm soil, 40 mm soil + 40 mm rockwool, 80 mm soil, and 80 mm soil + 40 mm rockwool on stormwater mitigation performance relative to control were analyzed. Three core performance indicators (percent retention, peak delay, and peak reduction) were employed to evaluate green roof performance. The results suggest that, while the retention performance of the studied green roofs under Hong Kong's heavy rainfall regime seems to be less effective, remarkable peak reduction and peak delay were observed even when the green roof system has reached full moisture-storage capacity. Such findings are in line with the proposed Green-roof System Capacity model that green roof serves as an effective buffer that regulates water flow through the system. No statistical significance was found between substrate-depth treatments, despite the higher performance across all three indicators for treatment 80. However, satisfactory peak performance of the 40-mm thin substrate suggests that green roof can be applied even on existing buildings that have limited loading capacity. Pertinent meteorological factors were identified. All in all, extensive green roof remains as an effective and promising alternative mitigation strategy to urban stormwater management in Hong Kong with potential application to other tropical areas. DOI: 10.5353/th_b5194727 Subjects: Green roofs (Gardening)

Download or read book Plant Selection Irrigation Requirements and Stormwater Management of Pacific Northwest Extensive Green Roofs written by Erin Shroll and published by . This book was released on 2010 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: An alternative to traditional roofing, extensive green roofs are contained ecosystems consisting of a drainage layer, a thin media profile which is planted with hardy plant species. Extensive green roof plants must maintain multiple functions while growing in a highly aggregate media at a depth of equal to or less than 15.25 cm. The shallow media depth weighs less and can often be used when retrofitting an existing building with a green roof. Maximizing functions such as stormwater mitigation requires designing for the purpose of the green roof goal and for the maintenance plan that will ensure plant health in extreme environments. However, our understanding of these complex and dynamic ecosystems on rooftops is still very limited and management of green roofs is often an afterthought, rarely taking into account regional differences in climate. The establishment period of an extensive green roof is a critical time to promote plant coverage, which often requires irrigation during dry periods. The Pacific Northwest (PNW) climate is challenging for green roof management because plants experience cool wet conditions for much of the year yet must survive warm, nearly rainless summers. However, extensive green roof maintenance is generally minimal unless aesthetics are the primary goal. Maintenance in the second year and the years following includes irrigation during dry periods to keep plants healthy or to enhance green roof function. The removal of competitive weeds and tree seedlings is also recommended throughout the life of the green roof. Extensive green roofs are increasingly being used to help improve stormwater management. The vegetative portion of an extensive green roof design is often steered by the structural load that a building can hold along with availability of local products and materials such as media and plants. A lightweight, high aggregate media planted with Sedum species and other succulents is often selected as these components have been successful and work well together. However, with the drive to increase the functional role of extensive green roofs, media and plant selection must be further investigated to fully understand how we can optimize green roof efficiency--in our case, stormwater management efficiency, the most requested function of commercial green roofs. In this study green roof plants were provided adequate irrigation in the first summer and throughout establishment. At the start of the second summer, we tested how the eight taxa performed under three different management regimes in the PNW: (i) non-irrigated, ii) irrigated in compliance with Portland, Oregon's floor area ratio (FAR) bonus requirement and iii) according to out horticultural decision resulting in the highest watering regime. We also measured weed pressure across the irrigation treatments. We selected plant taxa based on their potential functional attributes (habitat quality, aesthetic quality, stormwater management proficiency) as well as their availability through the regional nursery trade. Plants selected were Camassia quamash, Cistus creticus ssp creticus 'Lasithi', Delosperma cooperi, Eriophyllum lanatum var lanatum, Festuca idahoensis var roemeri, Iris chrysophylla, Sedum spathulifolium 'Cape Blanco' and Sisyrinchium idahoense. Within selected seasons the mean relative growth rate (MRGR) of each plant was analyzed and survivorship was recorded throughout this study. Throughout the first year of establishment, all plants grew and survival was high. Exceptions were that I. chrysophylla declined in mean relative growth rate (MRGR) and D. cooperi had a twenty five percent loss in survival during a cold winter spell. Plant growth and overall plant performance varied considerably among taxa throughout establishment and across the summer irrigation treatments. Weed pressure also varied across treatments. The highest watering regime provided the greatest plant survivorship and plants generally had a positive increase in MRGR. Exceptions were F. idahoensis var roemeri, which decreased in MRGR and S. spathulifolium 'Cape Blanco' which did not change in size. The irrigation regime compliant with the City of Portland provided increased plant survivorship over the non-irrigated regime, yet plant aesthetics were less for the same species compared to the highest watering regime. Plant survivorship in the non-irrigated regime included succulents, D. cooperi and S. spathulifolium 'Cape Blanco', and the summer-dormant bulb, C. quamash. Plant aesthetics within each irrigation regime varied considerably and mean aesthetic ratings declined as the summer season progressed. These results suggest that tailoring green roof management more precisely to plant choices and the regional environment will improve function and reduce overall costs. Maintenance costs are less (water costs and weeding labor) with a non-irrigated green roof however, plant aesthetics are compromised when plants experience three to five days without water. Overall the collected runoff from rainfall throughout this study, planted green roofs retained 45% of roof runoff verses 40.5 % retained by media only roofs (p

Download or read book Evaluating Green Roof Stormwater Management in New York City written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the United States, an aging and overburdened urban infrastructure has become a substantial challenge for civil engineers. Among these challenges, systems for stormwater management are of significant concern, considering their direct impact on environmental quality, local ecosystems, and the hydrologic cycle. Given the high costs for rehabilitation of traditional stormwater infrastructure in urban settings, low impact, or "green" development strategies have become critical components in plans for meeting future stormwater management goals. In particular, New York City (NYC) has pledged $1.5 billion over the next 20 years to improve environmental quality through the mitigation of urban runoff, where utilization of green infrastructure is a primary goal. Cost effective implementation of this, and similar plans around the world, requires comprehensive understanding of green infrastructure functionality. In response, this dissertation investigates the stormwater management potential of full-scale green roofs in NYC through lenses of observation, modeling, and design.

Download or read book Nutrient Dynamics in Stormwater Runoff from Green Roofs with Varying Substrate written by John Michael Fohner and published by . This book was released on 2012 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: One major concern with urban development is the increasing amount of stormwater runoff from large expanses of impervious surfaces. These impervious surfaces reduce the ability of stormwater to infiltrate into the soil and eventually groundwater, which leads to greater amounts of surface runoff. Green technology serves as a viable solution to many of the environmental problems presented by modern development. Fifteen mock, extensive green roofs were built in the fall of 2008 at the Watershed Research and Education Center in Fayetteville, Arkansas. The goals of this project were to (1) measure the amount of stormwater runoff from varying treatments and control roofs, (2) measure the stormwater runoff quality from varying treatments, and (3) study the release of nutrients over time from the green roofs with added compost. Our results show that after an initial flush of nutrients from green roofs with added compost, many nutrient concentrations, such as total organic carbon (TOC), total nitrogen (TN), nitrate-N (NO3-N), and other physiochemical properties have been reduced. However, even after two years, P concentrations in runoff water still exceed 1 mg/L from green roofs using compost in the growing matrix. Analysis of the remaining nutrients in the compost shows that TP loads from green roofs with added compost could be elevated for a number of years. The results from this study provide a benchmark for developing green roofs in Northwest Arkansas or other similar climactic regions

Download or read book Roof Gardens written by Theodore Osmundson and published by W. W. Norton & Company. This book was released on 1999-08-03 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: An illustrated study of gardens built on the roofs of buildings traces the history of roof gardens, from the Hanging Gardens of Babylon to the present; explains how to construct safe, durable gardens; and offers tips on selecting plants, garden maintenance, and planting techniques.

Download or read book Evaluation of Storm Water Runoff from a Midwest Green Roof System written by Krista Forrester and published by . This book was released on 2007 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rain Gardens written by Nigel Dunnett and published by Timber Press (OR). This book was released on 2007 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rain gardens encompass all possible elements that can be used to capture, channel, divert and make the most of the rain and snow that fall on a property. They have the potential to make beautiful additions to our environment. Rain Gardens is the first book on sustainable water management schemes suitable for students and professionals.

Download or read book Evaluation of a Green Roof System with Various Growing Media Sedum Species and Fertilizer Treatments written by Julie Gibbs-Alley and published by . This book was released on 2008 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Dynamic Stormwater Reponse of a Green Roof written by Bruce Martin and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Dynamic Stormwater Reponse of a Green Roof written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Impervious surfaces negatively affect urban hydrology by altering the depth, frequency and seasonal distribution of stormwater runoff. To assess the imperviousness of green roofs, a mathematical model was developed to simulate the stormwater response of a hypothetical green roof. The model is based on the physical processes that affect the green roof stormwater response and uses historic climate data. The results show that green roof imperviousness fluctuated according to climate conditions and precipitation sequence. Only 29% of the total precipitation received by the green roof resulted in runoff, however, the response varied substantially when evaluated at a daily interval. Runoff was eliminated during 82% of days with rain and a higher proportion of runoff disturbances were eliminated during the spring and summer compared to the fall. In comparison to an impervious surface, the green roof showed a reduction in the depth and frequency of runoff thereby improving urban hydrology.