Parallel computing in conceptual sewer simulations

2010 ◽  
Vol 61 (2) ◽  
pp. 283-291 ◽  
Author(s):  
G. Burger ◽  
S. Fach ◽  
H. Kinzel ◽  
W. Rauch
Keyword(s):  
Parallel Computing ◽  
Software Tool ◽  
Computational Time ◽  
Limiting Factor ◽  
Urban Drainage ◽  
Pollution Effects ◽  
Drainage Systems ◽  
Sewer Systems ◽  
Urban Drainage Systems

Integrated urban drainage modelling is used to analyze how existing urban drainage systems respond to particular conditions. Based on these integrated models, researchers and engineers are able to e.g. estimate long-term pollution effects, optimize the behaviour of a system by comparing impacts of different measures on the desired target value or get new insights on systems interactions. Although the use of simplified conceptual models reduces the computational time significantly, searching the enormous vector space that is given by comparing different measures or that the input parameters span, leads to the fact, that computational time is still a limiting factor. Owing to the stagnation of single thread performance in computers and the rising number of cores one needs to adapt algorithms to the parallel nature of the new CPUs to fully utilize the available computing power. In this work a new developed software tool named CD3 for parallel computing in integrated urban drainage systems is introduced. From three investigated parallel strategies two showed promising results and one results in a speedup of up to 4.2 on an eight-way hyperthreaded quad core CPU and shows even for all investigated sewer systems significant run-time reductions.

Long-term versus Real-time Optimal Operation for Gate Regulation during Flood in Urban Drainage Systems

2018 ◽  
Vol 15 (8) ◽  
pp. 750-759 ◽  
Author(s):  
Fatemeh Jafari ◽  
S. Jamshid Mousavi ◽  
Jafar Yazdi ◽  
Joong Hoon Kim
Keyword(s):  
Real Time ◽  
Optimal Operation ◽  
Urban Drainage ◽  
Drainage Systems ◽  
Urban Drainage Systems ◽  
Time Optimal

The effects of non-stationarity on the evaluation of critical design storms

1998 ◽  
Vol 37 (11) ◽  
pp. 187-193 ◽  
Author(s):  
C. De Michele ◽  
A. Montanari ◽  
R. Rosso
Keyword(s):  
Daily Rainfall ◽  
Extreme Value Distribution ◽  
Flood Management ◽  
Extreme Value ◽  
Urban Drainage ◽  
Drainage Systems ◽  
Design Storm ◽  
Critical Design ◽  
Urban Drainage Systems

The critical storm is generally carried out to design urban drainage systems and other flood management works starting from the available historical information. Its evaluation associated with a fixed return period is usually obtained by fitting the annual maxima of the rainfall depth with an extreme value distribution. This statistical procedure, however, leads to dubious results when the data present a non-stationarity, induced for example, by a long-term variability. To assess the effects of non-stationarity, four daily rainfall series observed in Italy, with at least 90 years of continuous data, are analysed here. For each record and each year of the observation period, critical design storms are estimated fitting the annual maxima collected in the past, so allowing us to assess the progress of the design storm along time. Four different extreme value distributions are used. The results show that an analysis of non-stationarity is required when urban drainage systems and other hydraulic engineering works are designed.

scholarly journals Sustainable Urban Drainage Systems in Spain: Analysis of the Research on SUDS Based on Climatology

2021 ◽  
Vol 13 (13) ◽  
pp. 7258
Author(s):  
Ana Isabel Abellán García ◽  
Noelia Cruz Pérez ◽  
Juan C. Santamarta
Keyword(s):  
Iberian Peninsula ◽  
Green Infrastructure ◽  
Rainwater Harvesting ◽  
Economic Feasibility ◽  
Limiting Factor ◽  
Urban Drainage ◽  
Climate Change Research ◽  
Drainage Systems ◽  
Mitigation And Adaptation ◽  
Urban Drainage Systems

Sustainable urban drainage systems (SUDS), or urban green infrastructure for stormwater control, emerged for more sustainable management of runoff in cities and provide other benefits such as urban mitigation and adaptation to climate change. Research in Spain began a little over twenty years ago, which was later than in other European countries, and it began in a heterogeneous way, both in the SUDS typology and spatially within the peninsular geography. The main objective of this work has been to know through bibliographic review the state of the art of scientific research of these systems and their relationship with the different types of climates in the country. These structures have a complex and sensitive dependence on the climate, which in the Iberian Peninsula is mostly type B and C (according to the Köppen classification). This means little water availability for the vegetation of some SUDS, which can affect the performance of the technique. To date, for this work, research has focused mainly on green roofs, their capabilities as a sustainable construction tool, and the performance of different plant species used in these systems in arid climates. The next technique with the most real cases analyzed is permeable pavements in temperate climates, proving to be effective in reducing flows and runoff volumes. Other specific investigations have focused on the economic feasibility of installing rainwater harvesting systems for the laundry and the hydraulic performance of retention systems located specifically in the northeast of the Iberian Peninsula. On the contrary, few scientific articles have appeared that describe other SUDS with vegetation such as bioretention systems or green ditches, which are characteristic of sustainable cities, on which the weather can be a very limiting factor for their development.

Urban Drainage Systems: Design and Operation

1993 ◽  
Vol 27 (12) ◽  
pp. 31-70 ◽  
Author(s):  
J. Marsalek ◽  
T. O. Barnwell ◽  
W. Geiger ◽  
M. Grottker ◽  
W. C. Huber ◽  
...  
Keyword(s):  
Sewage Treatment ◽  
Systems Design ◽  
Urban Drainage ◽  
Sewer System ◽  
Drainage Systems ◽  
Planning And Design ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Urban Drainage Systems ◽  
Receiving Waters

Design and operation of urban drainage systems are addressed in the context of the urban water system comprising drainage, sewage treatment plants and receiving waters. The planning and design of storm sewers are reviewed with reference to planning objectives, design objectives, flows and pollutant loads, sewer system structures and urban runoff control and treatment. The discussion of combined sewers focuses on hydraulic design of combined sewer systems, including combined sewer overflow (CSO) structures, and the use of CSO structures and storage in control of CSOs. The section on operation of sewer systems focuses on real time control, its feasibility, planning, design, operation and applications. Sewer system planning and design are generally conducted using computer modelling tools and procedures which are reviewed in the last section. A brief listing of selected models focuses on internationally used models. Finally, it was concluded that further improvements in environmental and ecological protection of urban waters is feasible only by consideration of urban drainage systems in conjunctions with sewage treatment and water quality in the receiving waters.

Performance assessment of separate and combined sewer systems in metropolitan areas in southern China

2013 ◽  
Vol 69 (2) ◽  
pp. 422-429 ◽  
Author(s):  
Tian Li ◽  
Wei Zhang ◽  
Cang Feng ◽  
Jun Shen
Keyword(s):  
Performance Assessment ◽  
Metropolitan Areas ◽  
Southern China ◽  
Drainage System ◽  
Practical Experience ◽  
Urban Drainage ◽  
Drainage Systems ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Urban Drainage Systems

To assess the performance of urban drainage systems in metropolitan areas in southern China, 12 urban drainage systems, including nine separate sewer systems (SSSs) and three combined sewer systems (CSSs) were monitored from 2008 to 2012 in Shanghai and Hefei. Illicit connection rates of SSS were determined. The results indicate that serious illicit connections exist for most SSSs. Annual volume balance for two SSSs with serious illicit connection was assessed with a hydraulic model to determine the dry weather overflow volume. Although interception facilities have been implemented in SSSs, for some systems with serious illicit connections, a considerable volume of dry weather overflow still existed. Combined with monitoring of dry/wet weather flow quality, the pollutant load caused by wet/dry weather overflow was quantified. The results revealed that there was no obvious advantage of having SSSs over CSSs in terms of pollutant control. The serious pollution caused by illicit connections and insufficient management occurs in many cities in China. The performance assessment of separate and CSSs in Shanghai and Hefei provides important lessons and practical experience that can be applied to the construction and management of urban drainage system in China as well as other developing countries.

Nowcasting of rainfall and of combined sewage flow in urban drainage systems

2009 ◽  
Vol 59 (6) ◽  
pp. 1145-1151 ◽  
Author(s):  
Stefan Achleitner ◽  
Stefan Fach ◽  
Thomas Einfalt ◽  
Wolfgang Rauch
Keyword(s):  
Spatial Scales ◽  
Radar Data ◽  
Urban Drainage ◽  
Real Time Control ◽  
Sewer System ◽  
Drainage Systems ◽  
Time Control ◽  
Sewer Systems ◽  
Urban Drainage Systems ◽  
The City

Nowcasting of rainfall may be used additionally to online rain measurements to optimize the operation of urban drainage systems. Uncertainties quoted for the rain volume are in the range of 5% to 10% mean square error (MSE), where for rain intensities 45% to 75% MSE are noted. For larger forecast periods up to 3 hours, the uncertainties will increase up to some hundred percents. Combined with the growing number of real time control concepts in sewer systems, rainfall forecast is used more and more in urban drainage systems. Therefore it is of interest how the uncertainties influence the final evaluation of a defined objective function. Uncertainty levels associated with the forecast itself are not necessarily transferable to resulting uncertainties in the catchment's flow dynamics. The aim of this paper is to analyse forecasts of rainfall and specific sewer output variables. For this study the combined sewer system of the city of Linz in the northern part of Austria located on the Danube has been selected. The city itself represents a total area of 96 km2 with 39 municipalities connected. It was found that the available weather radar data leads to large deviations in the forecast for precipitation at forecast horizons larger than 90 minutes. The same is true for sewer variables such a CSO overflow for small sub-catchments. Although the results improve for larger spatial scales, acceptable levels at forecast horizons larger than 90 minutes are not reached.

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