scholarly journals A modelling study of the event-based retention performance of green roof under the hot-humid tropical climate in Kuching

2017 ◽  
Vol 76 (11) ◽  
pp. 2988-2999 ◽  
Author(s):  
C. T. Chai ◽  
F. J. Putuhena ◽  
O. S. Selaman

Abstract The influences of climate on the retention capability of green roof have been widely discussed in existing literature. However, knowledge on how the retention capability of green roof is affected by the tropical climate is limited. This paper highlights the retention performance of the green roof situated in Kuching under hot-humid tropical climatic conditions. Using the green roof water balance modelling approach, this study simulated the hourly runoff generated from a virtual green roof from November 2012 to October 2013 based on past meteorological data. The result showed that the overall retention performance was satisfactory with a mean retention rate of 72.5% from 380 analysed rainfall events but reduced to 12.0% only for the events that potentially trigger the occurrence of flash flood. By performing the Spearman rank's correlation analysis, it was found that the rainfall depth and mean rainfall intensity, individually, had a strong negative correlation with event retention rate, suggesting that the retention rate increases with decreased rainfall depth. The expected direct relationship between retention rate and antecedent dry weather period was found to be event size dependent.

Author(s):  
Laima TAPARAUSKIENĖ ◽  
Veronika LUKŠEVIČIŪTĖ

This study provides the analysis of drought conditions of vegetation period in 1982-2014 year in two Lithuanian regions: Kaunas and Telšiai. To identify drought conditions the Standardized Precipitation Index (SPI) was applied. SPI was calculated using the long-term precipitation record of 1982–2014 with in-situ meteorological data. Calculation step of SPI was taken 1 month considering only vegetation period (May, June, July, August, September). The purpose of investigation was to evaluate the humidity/aridity of vegetation period and find out the probability of droughts occurrence under Lithuanian climatic conditions. It was found out that according SPI results droughts occurred in 14.5 % of all months in Kaunas region and in 15.8 % in Telšiai region. Wet periods in Kaunas region occurred in 15.8 %, and in Telšiai region occurrence of wet periods was – 18.8 % from all evaluated months. According SPI evaluation near normal were 69.7 % of total months during period of investigation in Kaunas and respectively – 65.5 % in Telšiai. The probability for extremely dry period under Lithuania climatic conditions are pretty low – 3.0 % in middle Lithuania and 2.4 % in western part of Lithuania.


2021 ◽  
Vol 13 (6) ◽  
pp. 3078
Author(s):  
Elena Giacomello ◽  
Jacopo Gaspari

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.


Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1217 ◽  
Author(s):  
Yongwei Gong ◽  
Dingkun Yin ◽  
Xing Fang ◽  
Junqi Li

The runoff retention effectiveness of 10 extensive green roof (EGR) modules (100 mm substrate planted Sedum lineare Thunb.) were analyzed in Beijing for 22 rainfall events (2.4–46.4 mm) from 1 July to 30 September 2017. Differences between minimum inter-event dry periods, module scales, substrate hydraulic conductivity and depths, drainage layer types and rainfall characteristics were examined to study their correlation to the retention performance of EGRs. In general, EGRs with lower substrate hydraulic conductivity, deeper substrate and lower rainfall depth had higher runoff retention performance. By comparsion, no siginificant correlation was found between rainfall duration, prior dry period, average rainfall intensity, drainage layer type and EGR runoff retention rate. Analyses of variance (ANOVA) and Tukey tests supported these results. Low or moderate rainfall (<15 mm) may or may not have an effect, but heavy rainfall (>25 mm) definitely affects the EGR retention performance of the next rainfall event.


2022 ◽  
Author(s):  
Motomu Suzuki ◽  
Koukichi Koukichi ◽  
Taro Mikami ◽  
Yuichiro Yabuki ◽  
Saori Asano ◽  
...  

Abstract Since cellulitis is one of the most important factors for the prognosis of lymphedema, the prevention and prediction of cellulitis are considered to be critical in controlling lymphedema. We hypothesized that patients with lymphedema might show meteoropathy, as abdominal aortic aneurysm ruptures are considered to be influenced by climatic conditions, and the lymphatic system is one of the circulation systems. Thus, we aimed to determine if the onset of cellulitis in limbs affected by lymphedema is related to climatic conditions. We reviewed the clinical records of patients with lymphedema admitted for cellulitis at our institute between January 2007 and December 2017. We identified 40 patients, 25 of whom lived in the same area. We examined the association between the number of patient admissions according to season and meteorological data obtained from the Japan Meteorological Agency database. Thirteen of 25 patients were admitted in summer, whereas only one patient was admitted in winter. Both higher temperature and lower atmospheric pressure around the day of admission were associated with the occurrence of cellulitis. Lymphedema may be regarded as a meteoropathic disease, as climatic conditions were shown to be associated with cellulitis in limbs affected by lymphedema.


1963 ◽  
Vol S7-V (3) ◽  
pp. 303-306 ◽  
Author(s):  
Andre Klingebiel

Abstract Examination of a section which cuts into the Dreuilhe anticline in the southern Aquitaine basin (Plantaurel) reveals a similarity between the deposits there and those in the northern part of the basin. In the core of the anticline the Maestrichtian lower red marls contain clays and red sandstone with montmorillonite and kaolinite, suggesting deposition in a vast depression lacking sufficient drainage, and in a medium rich in Ca (super ++) and Mg (super ++) . The upper red marls in the hard band of Montian lacustrine limestone with Microcodium have an analogous composition and correspond to calm tectonic and climatic conditions. Lacustrine marls with attapulgite directly underlie the transgressive Thanetian marine deposits. The passage from the Thanetian to the Sparnacian is marked by lacustrine facies, predominantly montmorillonite, and an increasing abundance of illites. The dominance of montmorillonite in a tectonically unstable area suggests that the adjacent continental mass was of low relief and was characterized by a tropical climate with alternating dry and humid seasons. The increase in kaolinite accompanying the arrival of the coarse detritus of the Ypresian is interpreted as the result of rhexistasy. The Lutetian is characterized by sandstones and limestones with associated montmorillonite, illite, and kaolinite. This phase represents the return of the sea, and the detrital nature of the deposits is a result of the uplift of the Pyrenean massifs. These phenomena are analogous to those that have been reported previously from the Paleocene series of Bordelais (northern part of the basin) suggesting a similar paleogeographic evolution for the two areas.


2020 ◽  
Vol 175 ◽  
pp. 11023
Author(s):  
Elena Sysoeva ◽  
Margarita Gelmanova

Over the past 20 years, a large number of studies have been published on reducing storm runoff by various types of green roofs. This article analyzes the results of experimental studies presented in 39 publications on green roof runoff reduction in a climate similar to the climate of Russia: in Canada, the USA, Finland, Norway, France. An analytical review found that the ability of green roofs to retain rainfall varies from 20 to 99.5% depending on climatic conditions (duration and intensity of rains, duration of dry periods, solar radiation, temperature and humidity, wind conditions), the properties of green roof layers (moisture capacity of the substrate and a drainage layer, the substrate thickness), the type of vegetation, the geometry of a green roof (slope and orientation). Green roofs can be a useful tool for reducing urban storm water runoff. However, in order to ensure high efficiency, it is necessary to use green roof technology with other measures to reduce runoff.


2019 ◽  
Vol 42 ◽  
pp. e42475
Author(s):  
Vivian Dielly da Silva Farias ◽  
Deborah Luciany Pires Costa ◽  
Joao Vitor de Novoa Pinto ◽  
Paulo Jorge Oliveira Ponte de Souza ◽  
Everaldo Barreiro de Souza ◽  
...  

The use of empirical agrometeorological models that can be adjusted to the climatic conditions of different regions has become increasingly necessary to improve water management in grain-producing municipalities. The aim of this work is to examine the correlation between various reference evapotranspiration (ETo) estimation methods and the standard FAO 56 Penman-Monteith method, as well as to determine correction factors, when necessary, for crop-producing municipalities in the northeast of Pará, during both the rainy and dry seasons. We compared simpler methods of ETo estimation to the FAO 56 Penman-Monteith method. For this purpose, meteorological data from Tracuateua, Bragança, Capitão Poço and Castanhal, provided by the National Institute of Meteorology (INMET), were used. The calibration of equations was performed through linear regression. The accuracy of different estimation methods was examined. The Turc, FAO 24 Blaney-Criddle and regression methods presented the best results for all statistical criteria; the Priestley-Taylor, Makkink and FAO 24 Radiation methods presented excellent results after calibration. The methods of Camargo and Hargreaves-Samani produced the worst results for all the criteria.


Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 929 ◽  
Author(s):  
David Dunkerley

In many studies of landsurface processes, the intensity of rainfall events is expressed with clock-period indexes such as I30, the wettest 30-minute interval within a rainfall event. Problematically, the value of I30 cannot be estimated for rainfall events shorter than 30 min, excluding many intense convective storms. Further, it represents a diminishing proportion of increasingly long rainfall events, declining to <2% of the duration of a 30-hour event but representing 25% of the duration of a two-hour event. Here, a new index termed EDf5 is proposed: It is the rainfall depth in the wettest 5% of the event duration. This can be derived for events of any duration. Exploratory determinations of EDf5 are presented for two Australian locations with contrasting rainfall climatologies—one arid and one wet tropical. The I30 index was similar at both sites (7.7 and 7.9 mm h−1) and was unable to differentiate between them. In contrast, EDf5 at the arid site was 7.4 mm h−1, whilst at the wet tropical site, it was 3.8 mm h−1. Thus, the EDf5 index indicated a greater concentration of rain at the arid site where convective storms occurred (i.e., the intensity sustained for 5% of event duration at that site is higher). The EDf5 index can be applied to short, intense events that can readily be included in the analysis of event-based rainfall intensity. I30 therefore appears to offer less discriminatory power and consequently may be of less value in the investigation of rainfall characteristics that drive many important landsurface processes.


Sign in / Sign up

Export Citation Format

Share Document