A 1-h urban design storm for Canada

1986 ◽  
Vol 13 (3) ◽  
pp. 293-300 ◽  
Author(s):  
W. E. Watt ◽  
K. C. A. Chow ◽  
W. D. Hogg ◽  
K. W. Lathem
Keyword(s):  
Urban Design ◽  
Regional Analysis ◽  
Temporal Distribution ◽  
Atmospheric Environment ◽  
Design Storm ◽  
Wide Range ◽  
Modelling Techniques ◽  
Intensity Duration Frequency ◽  
Two Parameters ◽  
Environment Service

The advent of stormwater modelling techniques has resulted in the need for a Canadian urban design storm. As a first stage in meeting this need, a 1-h urban design storm has been developed. This design storm, which is fully described by two parameters and the rainfall depth as given by Atmospheric Environment Service (AES) intensity–duration–frequency data, is specified for a wide range of return periods for all regions of Canada. Extensive comparisons with observed 1-h storms, both in the temporal domain and the frequency domain, indicate that the two-parameter mathematical model is capable of simulating individual rainfall events and an average or 'design' event for any particular site. The design storm model has been extended on a regional basis by evaluating the two parameters for each of 45 AES stations across Canada. Regional values of the parameters have been derived so that a design storm can be determined for an area without rainfall records. Key words: design storm, urban drainage, storm water, rainfall, temporal distribution, regional analysis.

Design storms for urban drainage design

1984 ◽  
Vol 11 (3) ◽  
pp. 574-584 ◽  
Author(s):  
J. Marsalek ◽  
W. E. Watt
Keyword(s):  
Computational Procedure ◽  
Design Flow ◽  
Atmospheric Environment ◽  
Urban Drainage ◽  
Design Storm ◽  
Antecedent Conditions ◽  
Wide Range ◽  
Drainage Design ◽  
Definition Of ◽  
Environment Service

The design storm concept is well established in Canadian urban drainage practice, but appropriate use is hindered by an incomplete definition of design storms and their applications. To remedy this situation, it is recommended that design storms be described for various regions and a wide range of durations and return periods; these storms should be based on local Atmospheric Environment Service (AES) rainfall data, given for both the rational method and hydrograph model applications, and supplemented by specifications of the computational procedure and normal antecedent conditions. Such design storms would produce peak flows of approximately the same return period as that of the design flow. None of the existing design storms has all these features but an acceptable set of design storms could be developed using existing Canadian data. Key words: design storms, urban drainage, stormwater, hydrological design, precipitation, runoff computations.

Temporal Distribution of Design Storm Rainfall

1984 ◽  
Vol 16 (8-9) ◽  
pp. 167-175
Author(s):  
J Marsalek
Keyword(s):  
Urban Design ◽  
Comparative Studies ◽  
Temporal Distribution ◽  
Rainfall Distribution ◽  
Design Storm ◽  
Basic Characteristics ◽  
Storm Rainfall

Basic characteristics of urban design storms are presented and discussed. One of these characteristics, the temporal rainfall distribution, is further examined by demonstrating its effect on simulated runoff peaks and by comparing various distributions found in the literature. General comparisons of temporal distributions indicate large differences among various distributions. Further comparative studies and exchange of experience are recommended.

Optimal rainfall temporal patterns for urban drainage design in the context of climate change

2010 ◽  
Vol 62 (5) ◽  
pp. 1170-1176 ◽  
Author(s):  
V.-T.-V. Nguyen ◽  
N. Desramaut ◽  
T.-D. Nguyen
Keyword(s):  
Climate Change ◽  
Extreme Value Distribution ◽  
Climate Change Impacts ◽  
Atmospheric Environment ◽  
Systematic Evaluation ◽  
Accurate Estimation ◽  
Urban Drainage ◽  
Design Storm ◽  
Drainage Design ◽  
Environment Service

The main objective of the present study is to propose a method for estimating an optimal temporal storm pattern for urban drainage design in southern Quebec (Canada) in the context of climate change. Following a systematic evaluation of the performance of eight popular design storm models for different typical urban basins, it was found that the Canadian Atmospheric Environment Service (AES) storm pattern and the Desbordes model (with a peak intensity duration of 30 min) were the most accurate for estimating runoff peak flows while the Watt model gave the best estimation of runoff volumes. Based on these analyses, an optimal storm pattern was derived for southern Quebec region. The proposed storm pattern was found to be the most suitable for urban drainage design in southern Quebec since it could provide accurate estimation of both runoff peak flow and volume. Finally, a spatial-temporal downscaling method, based on a combination of the spatial statistical downscaling SDSM technique and the temporal scaling General Extreme Value distribution, was used to assess the climate change impacts on the proposed optimal design storm pattern and the resulting runoff properties.

scholarly journals A two-parameter design storm for Mediterranean convective rainfall

2017 ◽  
Vol 21 (5) ◽  
pp. 2377-2387 ◽  
Author(s):  
Rafael García-Bartual ◽  
Ignacio Andrés-Doménech
Keyword(s):  
Return Period ◽  
Geographic Location ◽  
Auxiliary Variable ◽  
Rainfall Regime ◽  
High Temporal Resolution ◽  
Design Storm ◽  
Starting Point ◽  
Intensity Duration Frequency ◽  
Two Parameters ◽  
Two Parameter

Abstract. The following research explores the feasibility of building effective design storms for extreme hydrological regimes, such as the one which characterizes the rainfall regime of the east and south-east of the Iberian Peninsula, without employing intensity–duration–frequency (IDF) curves as a starting point. Nowadays, after decades of functioning hydrological automatic networks, there is an abundance of high-resolution rainfall data with a reasonable statistic representation, which enable the direct research of temporal patterns and inner structures of rainfall events at a given geographic location, with the aim of establishing a statistical synthesis directly based on those observed patterns. The authors propose a temporal design storm defined in analytical terms, through a two-parameter gamma-type function. The two parameters are directly estimated from 73 independent storms identified from rainfall records of high temporal resolution in Valencia (Spain). All the relevant analytical properties derived from that function are developed in order to use this storm in real applications. In particular, in order to assign a probability to the design storm (return period), an auxiliary variable combining maximum intensity and total cumulated rainfall is introduced. As a result, for a given return period, a set of three storms with different duration, depth and peak intensity are defined. The consistency of the results is verified by means of comparison with the classic method of alternating blocks based on an IDF curve, for the above mentioned study case.

scholarly journals Estimation of the G2P Design Storm from a Rainfall Convectivity Index

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1943
Author(s):  
Rosario Balbastre-Soldevila ◽  
Rafael García-Bartual ◽  
Ignacio Andrés-Doménech
Keyword(s):  
Shape Parameter ◽  
Rainfall Intensity ◽  
Analytical Relationship ◽  
Urban Drainage ◽  
Practical Application ◽  
Resolution Time ◽  
Simple Method ◽  
Design Storm ◽  
Intensity Duration Frequency ◽  
Two Parameter

The two-parameter gamma function (G2P) design storm is a recent methodology used to obtain synthetic hyetographs especially developed for urban hydrology applications. Further analytical developments on the G2P design storm are presented herein, linking the rainfall convectivity n-index with the shape parameter of the design storm. This step can provide a useful basis for future easy-to-handle rainfall inputs in the context of regional urban drainage studies. A practical application is presented herein for the case of Valencia (Spain), based on high-resolution time series of rainfall intensity. The resulting design storm captures certain internal statistics and features observed in the fine-scale rainfall intensity historical records. On the other hand, a direct, simple method is formulated to derivate the design storm from the intensity–duration–frequency (IDF) curves, making use of the analytical relationship with the n-index.

scholarly journals A Comparison of Some Methods of Deriving the Instantaneous Unit Hydrograph

1985 ◽  
Vol 16 (1) ◽  
pp. 1-10 ◽  
Author(s):  
V. P. Singh ◽  
C. Corradini ◽  
F. Melone
Keyword(s):  
Peak Flow ◽  
Central Italy ◽  
Effective Rainfall ◽  
Unit Hydrograph ◽  
Time To Peak ◽  
Wide Range ◽  
Instantaneous Unit Hydrograph ◽  
Similar Accuracy ◽  
Two Parameters ◽  
Range Of Values

The geomorphological instantaneous unit hydrograph (IUH) proposed by Gupta et al. (1980) was compared with the IUH derived by commonly used time-area and Nash methods. This comparison was performed by analyzing the effective rainfall-direct runoff relationship for four large basins in Central Italy ranging in area from 934 to 4,147 km2. The Nash method was found to be the most accurate of the three methods. The geomorphological method, with only one parameter estimated in advance from the observed data, was found to be little less accurate than the Nash method which has two parameters determined from observations. Furthermore, if the geomorphological and Nash methods employed the same information represented by basin lag, then they produced similar accuracy provided the other Nash parameter, expressed by the product of peak flow and time to peak, was empirically assessed within a wide range of values. It was concluded that it was more appropriate to use the geomorphological method for ungaged basins and the Nash method for gaged basins.

2D X-ray diffraction and molecular modelling of the crystalline structure of polyesters under uniaxial stress

2021 ◽  
pp. 096739112199822
Author(s):  
Ahmed I Abou-Kandil ◽  
Gerhard Goldbeck
Keyword(s):  
Crystalline Structure ◽  
Molecular Modelling ◽  
Three Dimensional ◽  
Uniaxial Stress ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Modelling Techniques ◽  
Diffraction Patterns

Studying the crystalline structure of uniaxially and biaxially drawn polyesters is of great importance due to their wide range of applications. In this study, we shed some light on the behaviour of PET and PEN under uniaxial stress using experimental and molecular modelling techniques. Comparing experiment with modelling provides insights into polymer crystallisation with extended chains. Experimental x-ray diffraction patterns are reproduced by means of models of chains sliding along the c-axis leading to some loss of three-dimensional order, i.e. moving away from the condition of perfect register of the fully extended chains in triclinic crystals of both PET and PEN. This will help us understand the mechanism of polymer crystallisation under uniaxial stress and the appearance of mesophases in some cases as discussed herein.

scholarly journals Composition, Sources, and Distribution of PM2.5 Saccharides in a Coastal Urban Site of China

Atmosphere ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 274 ◽  
Author(s):  
Mengxin Xiao ◽  
Qiongzhen Wang ◽  
Xiaofei Qin ◽  
Guangyuan Yu ◽  
Congrui Deng
Keyword(s):  
Biomass Burning ◽  
Biological Activities ◽  
Process Analysis ◽  
Fungal Spores ◽  
Temporal Distribution ◽  
Urban Site ◽  
Pollution Levels ◽  
Haze Pollution ◽  
Wide Range ◽  
High Level

The characteristics of biogenic aerosols in an urban area were explored by determining the composition and temporal distribution of saccharides in PM2.5 in Shanghai. The total saccharides showed a wide range of 9.4 ng/m3 to 1652.9 ng/m3, with the averaged concentrations of 133.1 ng/m3, 267.5 ng/m3, 265.1 ng/m3, and 674.4 ng/m3 in spring, summer, autumn, and winter, respectively. The saccharides include anhydrosaccharides (levoglucosan and mannosan), which were higher in cold seasons due to the increased biomass burning; saccharide alcohols (mannitol, arabitol, sorbitol); and monosaccharides (fructose, glucose), which were more abundant in warm seasons and attributed to the biological emissions. Through positive matrix factorization (PMF) analysis, four emission sources of saccharides were resolved, including biomass burning, fungal spores, plant decomposition, and pollen. Moreover, the process analysis of high concentrations of leveglucosan was conducted by backward trajectory and fire points. We found that concentrations of anhydrosaccharides were relatively stable under different pollution levels, while saccharide alcohols exhibited an obvious decrease with the concentration of PM2.5, indicating that biomass burning was not the core reason for heavy haze pollution. However, high level PM2.5 pollution might inhibit the effects of biological activities.

scholarly journals A Cumulative Rainfall Function for Subhourly Design Storm in Mediterranean Urban Areas

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Marco Carbone ◽  
Michele Turco ◽  
Giuseppe Brunetti ◽  
Patrizia Piro
Keyword(s):  
Urban Areas ◽  
Goodness Of Fit ◽  
Nonlinear Least Squares ◽  
Least Square ◽  
Rainfall Time Series ◽  
Storm Events ◽  
Design Storm ◽  
Double Exponential ◽  
Two Parameters ◽  
Precipitation Records

Design storms are very useful in many hydrological and hydraulic practices and are obtained from statistical analysis of precipitation records. However considering design storms, which are often quite unlike the natural rainstorms, may result in designing oversized or undersized drainage facilities. For these reasons, in this study, a two-parameter double exponential function is proposed to parameterize historical storm events. The proposed function has been assessed against the storms selected from 5-year rainfall time series with a 1-minute resolution, measured by three meteorological stations located in Calabria, Italy. In particular, a nonlinear least square optimization has been used to identify parameters. In previous studies, several evaluation methods to measure the goodness of fit have been used with excellent performances. One parameter is related to the centroid of the rain distribution; the second one is related to high values of the standard deviation of the kurtosis for the selected events. Finally, considering the similarity between the proposed function and the Gumbel function, the two parameters have been computed with the method of moments; in this case, the correlation values were lower than those computed with nonlinear least squares optimization but sufficiently accurate for designing purposes.

scholarly journals A50 Whole-genome sequencing of African swine fever isolates from Sardinia

2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
C Torresi ◽  
F Granberg ◽  
L Bertolotti ◽  
A Oggiano ◽  
B Colitti ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sequence Data ◽  
Temporal Distribution ◽  
African Swine Fever ◽  
Amino Acid Identity ◽  
Genotype I ◽  
Acid Identity ◽  
Wide Range ◽  
Intergenic Sequences ◽  
Genes Encoding

Abstract In order to assess the molecular epidemiology of African swine fever (ASF) in Sardinia, we analyzed a wide range of isolates from wild and domestic pigs over a 31-year period (1978–2009) by genotyping sequence data from the genes encoding the p54 and the p72 proteins and the CVR. On this basis, the analysis of the B602L gene revealed a minor difference, placing the Sardinian isolates into two clusters according to their temporal distribution. As an extension of this study, in order to achieve a higher level of discrimination, three further variable genome regions, namely p30, CD2v, and I73R/I329L, of a large number of isolates collected from outbreaks in the years 2002–14 have been investigated. Sequence analysis of the CD2v region revealed a temporal subdivision of the viruses into two subgroups. These data, together with those from the B602L gene analysis, demonstrated that the viruses circulating in Sardinia belong to p72/genotype I, but since 1990 have undergone minor genetic variations in respect to its ancestor, thus making it impossible to trace isolates, enabling a more accurate assessment of the origin of outbreaks, and extending knowledge of virus evolution. To solve this problem, we have sequenced and annotated the complete genome of nine ASF isolates collected in Sardinia between 1978 and 2012. This was achieved using sequence data determined by next-generation sequencing. The results showed a very high identity with range of nucleotide similarity among isolates of 99.5 per cent to 99.9 per cent. The ASF virus (ASFV) genomes were composed of terminal inverted repeats and conserved and non-conserved ORFs. Among the conserved ORFs, B385R, H339R, and O61R-p12 showed 100 per cent amino acid identity. The same was true for the hypervariable ORFs, with regard to X69R, DP96R, DP60R, EP153R, B407L, I10L, and L60L genes. The EP402R and B602L genes showed, as expected, an amino acid identity range of 98.5 per cent to 100 per cent and 91 per cent to 100 per cent, respectively. In addition, all of the isolates displayed variable intergenic sequences. As a whole, the results from our studies confirmed a remarkable genetic stability of the ASFV/p72 genotype I viruses circulating in Sardinia.

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