scholarly journals Assessing the Retention Capacity of an Experimental Green Roof Prototype

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 90 ◽  
Author(s):  
Mariana da Silva ◽  
Mohammad K. Najjar ◽  
Ahmed W. A. Hammad ◽  
Assed Haddad ◽  
Elaine Vazquez
Keyword(s):  
Low Impact Development ◽  
Green Roof ◽  
Rain Event ◽  
Runoff Coefficient ◽  
Rainfall Runoff ◽  
Retention Capacity ◽  
Climatic Zones ◽  
Network Overload ◽  
Impervious Areas ◽  
Good Drainage

Cities with high urbanization produce impervious areas. Drainage network overload results in recurring flooding. Much of the damage could be prevented through proper urban planning and good drainage practices. While Low Impact Development techniques have been known for several years, it is essential to encourage the association of this type of technology with conventional micro-drainage structures to increase rainfall runoff at the source where it is generated. Thus, the present work aims to analyze the efficiency of the use of the green roof technique in reducing the peak of the flow and the retention capacity when subjected to heavy rains at the building scale, and also explores its effects in tropical climatic zones with measurements during the summer and fall. The method used was experimental analysis of the Green Roof prototype with bromeliad’s at CESA-UFRJ, whose main results are the hydrogram of each rain event and the runoff coefficient for rainfall in the range of 100 mm/h and 150 mm/h.

scholarly journals Assessing the significance of evapotranspiration in green roof modeling by SWMM

2018 ◽  
Vol 20 (3) ◽  
pp. 588-596 ◽  
Author(s):  
Aviva Gabriel Limos ◽  
Kristine Joy Bernardo Mallari ◽  
Jongrak Baek ◽  
Hwansuk Kim ◽  
Seungwan Hong ◽  
...  
Keyword(s):  
Urban Areas ◽  
Low Impact Development ◽  
Green Roof ◽  
Green Roofs ◽  
Management Model ◽  
Rainfall Runoff ◽  
Storm Water Management Model ◽  
Hydrologic Processes ◽  
Runoff Modeling ◽  
Modeling Software

Abstract Green roof is a low impact development (LID) practice used to mitigate imperviousness in urban areas and to reduce flood risks. In order to have sufficient designs and accurate runoff predictions, computer models should be utilized with full understanding of green roofs' hydrologic processes. Evapotranspiration is usually considered important by researchers in the water balance modeling of a green roof. The Storm Water Management Model (SWMM) version 5.1 is widely utilized rainfall-runoff modeling software which has LID controls capable of modeling green roofs. A previous study has evaluated the performance of this model in green roof simulations for single events without considering evapotranspiration in its application, but attained negative outcomes. Thus, the objective of this study is to determine the significance of considering evapotranspiration in producing accurate runoff simulations specifically using SWMM 5.1. The results of this study have shown that when evapotranspiration was not considered, simulations failed to agree with observed values, whereas when evapotranspiration was considered, simulated runoff volumes attained a very good fit with the observed runoff volumes proving the significance of evapotranspiration as an important parameter in green roof modeling.

scholarly journals A Review of Green Roof Applications for Managing Urban Stormwater in Different Climatic Zones

2018 ◽  
Vol 10 (8) ◽  
pp. 2864 ◽  
Author(s):  
Musa Akther ◽  
Jianxun He ◽  
Angus Chu ◽  
Jian Huang ◽  
Bert van Duin
Keyword(s):  
Review Paper ◽  
Low Impact Development ◽  
Green Roof ◽  
Stormwater Runoff ◽  
Green Roofs ◽  
Influential Factors ◽  
Urban Stormwater ◽  
Climatic Zones ◽  
Typical Type ◽  
Urban Stormwater Runoff

Many regions have turned to low impact development technologies (LIDs), which are implemented to restore the changes in stormwater runoff that have resulted from urbanization. Green roofs are one typical type of LID. Until now, many studies have validated their roles in managing urban stormwater runoff. However, they have also revealed that the performance of green roofs largely varies with their design configuration, as well as their hydro-climatic exposure. The objectives of this review paper are to statistically synthesize the effects of the influential factors, including design and hydrologic variables, on green roof performance and to explore their effects in different climatic zones. The review’s results confirm the differences in the influential variables and, thus, the performance of green roofs in different climatic zones. These are the barriers to knowledge translation among engineering designers, stormwater managers, and policymakers in different climatic zones when implementing green roofs. Consequently, region- or site-specific studies are necessary to implement green roofs with confidence.

Simulating rainfall runoff and assessing low impact development (LID) facilities in sponge airport

2020 ◽  
Vol 82 (5) ◽  
pp. 918-926
Author(s):  
Jing Peng ◽  
Xiang Zhong ◽  
Lei Yu ◽  
Qianqian Wang
Keyword(s):  
Water Depth ◽  
Low Impact Development ◽  
Green Roof ◽  
Reduction Rate ◽  
Low Frequency ◽  
Normal Operation ◽  
Return Periods ◽  
Rainfall Runoff ◽  
Reduction Effect ◽  
Total Inflow

Abstract The appearance of extreme weather causes frequent airport flooding, which has a serious impact on the normal operation of an airport. In this study, three simulation scenarios are set in order to study the effect of low impact development (LID) facilities (green roof and vegetative swale) on the water depth of overflow junctions and total inflow to the study area outlet in an airport at different rainfall return periods (2 a, 5 a, 20 a and 50 a). Vegetative swale has better reduction effect on water depth of overflow junctions than has green roof. The reduction rate of vegetative swale is about 25–52% at different rainfall return periods, but the effect of green roof is not obvious. For the double peak rainstorm, the reduction effect on the water depth of overflow junctions after setting vegetative swale for the first rain peak is better than that for the second rain peak. Under the condition of 2 a, 5 a, and 20 a, the total inflow reduction rates of study area outlet after applied green roof and vegetative swale are 16.85%, 20% and 22.17% respectively, and the effect is poor (only 2.26%) at low-frequency return period (50 a). This study can provide theoretical guidance for the design of LID facilities of a sponge airport.

Modifications of rainfall runoff and decision finding models for on-line simulation in real time control

1999 ◽  
Vol 39 (9) ◽  
pp. 201-207
Author(s):  
Andreas Cassar ◽  
Hans-Reinhard Verworn
Keyword(s):  
Real Time ◽  
Urban Drainage ◽  
Rain Event ◽  
Rainfall Runoff ◽  
Real Time Control ◽  
Design Storm ◽  
Time Control ◽  
Timing Data ◽  
On Line ◽  
Rainfall Runoff Model

Most of the existing rainfall runoff models for urban drainage systems have been designed for off-line calculations. With a design storm or a historical rain event and the model system the rainfall runoff processes are simulated, the faster the better. Since very recently, hydrodynamic models have been considered to be much too slow for real time applications. However, with the computing power of today - and even more so of tomorrow - very complex and detailed models may be run on-line and in real time. While the algorithms basically remain the same as for off-line simulations, problems concerning timing, data management and inter process communication have to be identified and solved. This paper describes the upgrading of the existing hydrodynamic rainfall runoff model HYSTEM/EXTRAN and the decision finding model INTL for real time performance, their implementation on a network of UNIX stations and the experiences from running them within an urban drainage real time control project. The main focus is not on what the models do but how they are put into action and made to run smoothly embedded in all the processes necessary in operational real time control.

scholarly journals Hydrologic Performance of an Extensive Green Roof under Intensive Rain Events: Results from a Rain-Chamber Simulation

2021 ◽  
Vol 13 (6) ◽  
pp. 3078
Author(s):  
Elena Giacomello ◽  
Jacopo Gaspari
Keyword(s):  
Water Retention ◽  
Green Roof ◽  
Green Roofs ◽  
International Standards ◽  
Dimensionless Number ◽  
Runoff Coefficient ◽  
Retention Performance ◽  
Extensive Green Roof ◽  
Rain Events ◽  
Hydrologic Performance

The water storage capacity of a green roof generates several benefits for the building conterminous environment. The hydrologic performance is conventionally expressed by the runoff coefficient, according to international standards and guidelines. The runoff coefficient is a dimensionless number and defines the water retention performance over a long period. At the scale of single rain events, characterized by varying intensity and duration, the reaction of the green roof is scarcely investigated. The purpose of this study is to highlight how an extensive green roof—having a supposed minimum water performance, compared to an intensive one—responds to real and repetitive rain events, simulated in a rain chamber with controlled rain and runoff data. The experiment provides, through cumulative curve graphs, the behavior of the green roof sample during four rainy days. The simulated rain events are based on a statistical study (summarized in the paper) of 25 years of rain data for a specific location in North Italy characterized by an average rain/year of 1100 mm. The results prove the active response of the substrate, although thin and mineral, and quick draining, in terms of water retention and detention during intense rain events. The study raises questions about how to better express the water performance of green roofs.

A Conceptual Tank Model for Urban Storm Water System

2013 ◽  
Vol 777 ◽  
pp. 430-433
Author(s):  
Xing Po Liu
Keyword(s):  
Low Impact Development ◽  
Water System ◽  
Storm Water ◽  
Rainfall Runoff ◽  
Sewer System ◽  
Tank Model ◽  
Objective Model ◽  
Principles Of Design ◽  
Urban Storm ◽  
Storm Sewer

In order to cope with urban flooding, water scarcity and rainfall-runoff pollution comprehensively, a conceptual tank model of urban storm water system is proposed. Tank model is a multi-layer, multi-objective model, so design of urban storm water system is more complex than that of urban storm sewer system. Some principles of design of urban storm water system are discussed, such as Low Impact Development, Smart storm water management, and so on.

scholarly journals IMPACT OF GREEN ROOF ON HEATING AND COOLING IN CONTEXT OF DIFFERENT CLIMATIC ZONES IN INDIA

2021 ◽  
pp. 436-440
Author(s):  
Ar. Ankur Bhardwaj ◽  
Dr. Shweta Chaudhary ◽  
Ar.Kirti Varandani
Keyword(s):  
Urban Areas ◽  
Green Roof ◽  
Green Roofs ◽  
Climatic Zones ◽  
Sustainable Living ◽  
Secondary Sources ◽  
Heating And Cooling ◽  
The World ◽  
Depth Study ◽  
Rainwater Runoff

The ecological, social and visual commitments that green roofs can make towards sustainable living in more intensified urban centres are generally recognized around the world. Green roof is one such sustainable methodology, utilization of which causes us in insulating the buildings and, subsequently contributing to better energy proficient execution of the same. Green roofs additionally give environment to various species, lessen the rainwater runoff and better deal with the carbon-dioxide cycle. In spite of these advantages, Green roofs are not as basic an element in India as they are in other European and American urban areas. In this paper an attempt has been made to enhance the advantages of this innovation in India. Green roofs systems looks simple in terms of setting up, but actually very complex in maintaining and achieving sustainability. In depth study of green roofs, historic background, climatic zones, impacts of green roofs on heating and cooling, benefits, problems and opportunities is done with the help of data taken from secondary sources like books, magazines and published literature (articles, journals, conference proceedings) form various e-libraries and other online platforms. KEY WORDS: Heating, Cooling, Green Roof, Sustainability)

scholarly journals High resolution rainfall – runoff measurement setup for green roof experiments in a tropical environment

2010 ◽  
Vol 7 (6) ◽  
pp. 9367-9410 ◽  
Author(s):  
T. Vergroesen ◽  
U. Man Joshi ◽  
N. C. van de Giesen ◽  
F. H. M. van de Ven
Keyword(s):  
High Resolution ◽  
Green Roof ◽  
Rain Gauge ◽  
Tropical Environment ◽  
Rainfall Runoff ◽  
External Disturbances ◽  
Data Treatment ◽  
Measuring Setup

Abstract. This article describes the measurement setup that is used for green roof experiments in a tropical environment, the required data treatment to obtain reliable values of rainfall, runoff and evapotranspiration, and how to deal with external disturbances that can influence the experiment results. High resolution rainfall runoff measurements to identify, understand and properly model the relevant runoff processes in a green roof require both tailored equipment and data treatment. A tipping bucket rain gauge is calibrated for and installed to measure minute based rain intensities. A runoff measuring setup is developed that can accurately quantify the runoff up to 6 l/min, and has a high resolution in both time and volume. Two different measuring setups are used to verify the evapotranspiration that is derived from the rainfall and runoff measurements.

scholarly journals The influence of a green roof drainage layer on retention capacity and leakage quality

2018 ◽  
Vol 77 (12) ◽  
pp. 2886-2895 ◽  
Author(s):  
Anna Baryła ◽  
Agnieszka Karczmarczyk ◽  
Andrzej Brandyk ◽  
Agnieszka Bus
Keyword(s):  
Water Quality ◽  
Green Roof ◽  
Life Sciences ◽  
Meteorological Station ◽  
Runoff Water ◽  
Retention Capacity ◽  
Drainage Layer ◽  
Second Year ◽  
Substrate Moisture ◽  
Leachate Quality

Abstract The aim of the research was to determine the influence of the substrate and different drainage materials on retention capacity and runoff water quality from three green roof containers. Phosphates were chosen as the water quality indicator based on their potential adverse impact on water quality in urban rainwater collectors. The field experiment was conducted at the Warsaw University of Life Sciences Water Center meteorological station in years 2013–2015. In terms of precipitation, the monitoring period covered a wet (+147.1 mm), average (+42.7 mm) and dry (− 66.3 mm) year. Leakage from the containers was recorded when the substrate moisture exceeded 20% and precipitation exceeded 3.5 mm/d for washed gravel, or 5.0 mm/d for a polypropylene mat and expanded clay. Phosphates were observed in leachates from all containers, with higher values observed in the second year of monitoring. As the result of this study, it can be concluded that the polypropylene mat and aggregates create different conditions for the formation of the leachate, in both volumes and its chemistry. The drainage layer made from a polypropylene mat is the most effective in terms of rainwater retention capacity and the resulting leachate quality.

scholarly journals Phosphorus and Metals Leaching from Green Roof Substrates and Aggregates Used in Their Composition

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 112 ◽  
Author(s):  
Agnieszka Karczmarczyk ◽  
Anna Baryła ◽  
Joanna Fronczyk ◽  
Agnieszka Bus ◽  
Józef Mosiej
Keyword(s):  
Heavy Metals ◽  
Green Roof ◽  
Green Roofs ◽  
Point Of View ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Batch Tests ◽  
Quality Literature ◽  
Materials Used ◽  
Runoff Quality

Green roofs are constructions made of different layers, each serving a dedicated function. Substrates and materials used in their composition are essential from the point of view of rainwater retention and plant development, but they may have an adverse effect on runoff quality. Literature studies show that phosphorus and heavy metals are of main importance. The total roofs area covered with green increased in the last years in cities as they are efficient in retention of rainwater and delaying of the runoff, therefore, protecting the cities against floods. As green roofs filtrate a significant amount of rainwater, materials used in substrates composition should be carefully selected to protect urban receivers against pollution. The aim of this study was to assess phosphorus and heavy metals leaching from different green roof substrates and their components with the focus on green roof runoff quality. Both commercially made green roof substrates and often used compounds (construction aggregates) were tested in laboratory batch tests for P, Cu, Ni, Cd, and Zn content in extracts. Based on the results of this study, it could be emphasized that a large part of commonly used construction aggregates can be a source of phosphorus, some also can release elevated values of nickel. Therefore, the materials should be carefully tested before use in the green roof substrate composition, not only for their physical properties reflecting water retention capacity, but also for chemical composition.

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