Identifying weak points of urban drainage systems by means of VulNetUD

2009 ◽  
Vol 60 (10) ◽  
pp. 2507-2513 ◽  
Author(s):  
M. Möderl ◽  
M. Kleidorfer ◽  
R. Sitzenfrei ◽  
W. Rauch
Keyword(s):  
Drainage System ◽  
Software Tool ◽  
Development Planning ◽  
Urban Drainage ◽  
Drainage Systems ◽  
Catchment Areas ◽  
Urban Drainage Systems ◽  
Weak Points ◽  
Vulnerability Maps

This article presents the development and application of the software tool VulNetUD. VulNetUD is a tool for GIS-based identification of vulnerable sites of urban drainage systems (UDS) using hydrodynamic simulations undertaken using EPA SWMM. The benefit of the tool is the output of different vulnerability maps rating sewer surcharging, sewer flooding, combined sewer overflow (CSO) efficiency and CSO emissions. For this, seven predefined performance indicators are used to evaluate urban drainage systems under abnormal, critical and future conditions. The application on a case study highlights the capability of the tool to identify weak points of the urban drainage systems. Thereby it is possible to identify urban drainage system components which cause the highest performance decrease across the entire system. The application of the method on a real world case study shows for instance that a reduction of catchment areas which are located upstream of CSOs with relatively less capacity in the downstream sewers achieves the highest increases efficiency of the system. Finally, the application of VulNetUD is seen as a valuable tool for managers and operators of waste water utilities to improve the efficiency of their systems. Additionally vulnerability maps generated by VulNetUD support risk management e.g. decision making in urban development planning or the development of rehabilitation strategies.

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.

scholarly journals Simulation of Flooding in Urban Drainage Systems (Case study: Shahzaderoodkhane Urban Watershed, Babolsar- Mazandran-Iran)

2017 ◽  
Vol 8 (15) ◽  
pp. 213-224
Author(s):  
مصطفی رشیدپور ◽  
کریم سلیمانی ◽  
کاکا شاهدی ◽  
ولی الله کریمی ◽  
◽  
...  
Keyword(s):  
Urban Drainage ◽  
Urban Watershed ◽  
Drainage Systems ◽  
Urban Drainage Systems

Does upward seepage of river water and storm water runoff determine water quality of urban drainage systems in lowland areas? A case study for the Rhine-Meuse delta

2009 ◽  
Vol 23 (21) ◽  
pp. 3110-3120 ◽  
Author(s):  
Kim Vermonden ◽  
Marion A. A. Hermus ◽  
Marije van Weperen ◽  
Rob S. E. W. Leuven ◽  
Gerard van der Velde ◽  
...  
Keyword(s):  
Water Quality ◽  
River Water ◽  
Storm Water ◽  
Water Runoff ◽  
Urban Drainage ◽  
Drainage Systems ◽  
Storm Water Runoff ◽  
Urban Drainage Systems

A stochastic approach for automatic generation of urban drainage systems

2009 ◽  
Vol 59 (6) ◽  
pp. 1137-1143 ◽  
Author(s):  
M. Möderl ◽  
D. Butler ◽  
W. Rauch
Keyword(s):  
Case Studies ◽  
Real World ◽  
Drainage System ◽  
Stochastic Approach ◽  
Automatic Generation ◽  
Urban Drainage ◽  
Sewer System ◽  
Urban Drainage System ◽  
Drainage Systems ◽  
Urban Drainage Systems

Typically, performance evaluation of new developed methodologies is based on one or more case studies. The investigation of multiple real world case studies is tedious and time consuming. Moreover extrapolating conclusions from individual investigations to a general basis is arguable and sometimes even wrong. In this article a stochastic approach is presented to evaluate new developed methodologies on a broader basis. For the approach the Matlab-tool “Case Study Generator” is developed which generates a variety of different virtual urban drainage systems automatically using boundary conditions e.g. length of urban drainage system, slope of catchment surface, etc. as input. The layout of the sewer system is based on an adapted Galton-Watson branching process. The sub catchments are allocated considering a digital terrain model. Sewer system components are designed according to standard values. In total, 10,000 different virtual case studies of urban drainage system are generated and simulated. Consequently, simulation results are evaluated using a performance indicator for surface flooding. Comparison between results of the virtual and two real world case studies indicates the promise of the method. The novelty of the approach is that it is possible to get more general conclusions in contrast to traditional evaluations with few case studies.

scholarly journals Partitioning the impacts of spatial and climatological rainfall variability in urban drainage modeling

2017 ◽  
Vol 21 (3) ◽  
pp. 1559-1572 ◽  
Author(s):  
Nadav Peleg ◽  
Frank Blumensaat ◽  
Peter Molnar ◽  
Simone Fatichi ◽  
Paolo Burlando
Keyword(s):  
Climate Variability ◽  
Rainfall Variability ◽  
Drainage System ◽  
Urban Drainage ◽  
Return Periods ◽  
Total Flow ◽  
Drainage Systems ◽  
Flow Variability ◽  
Urban Drainage Systems ◽  
Spatially Distributed

Abstract. The performance of urban drainage systems is typically examined using hydrological and hydrodynamic models where rainfall input is uniformly distributed, i.e., derived from a single or very few rain gauges. When models are fed with a single uniformly distributed rainfall realization, the response of the urban drainage system to the rainfall variability remains unexplored. The goal of this study was to understand how climate variability and spatial rainfall variability, jointly or individually considered, affect the response of a calibrated hydrodynamic urban drainage model. A stochastic spatially distributed rainfall generator (STREAP – Space-Time Realizations of Areal Precipitation) was used to simulate many realizations of rainfall for a 30-year period, accounting for both climate variability and spatial rainfall variability. The generated rainfall ensemble was used as input into a calibrated hydrodynamic model (EPA SWMM – the US EPA's Storm Water Management Model) to simulate surface runoff and channel flow in a small urban catchment in the city of Lucerne, Switzerland. The variability of peak flows in response to rainfall of different return periods was evaluated at three different locations in the urban drainage network and partitioned among its sources. The main contribution to the total flow variability was found to originate from the natural climate variability (on average over 74 %). In addition, the relative contribution of the spatial rainfall variability to the total flow variability was found to increase with longer return periods. This suggests that while the use of spatially distributed rainfall data can supply valuable information for sewer network design (typically based on rainfall with return periods from 5 to 15 years), there is a more pronounced relevance when conducting flood risk assessments for larger return periods. The results show the importance of using multiple distributed rainfall realizations in urban hydrology studies to capture the total flow variability in the response of the urban drainage systems to heavy rainfall events.

Cascade vulnerability for risk analysis of water infrastructure

2011 ◽  
Vol 64 (9) ◽  
pp. 1885-1891 ◽  
Author(s):  
R. Sitzenfrei ◽  
M. Mair ◽  
M. Möderl ◽  
W. Rauch
Keyword(s):  
Water Management ◽  
Risk Analysis ◽  
Water Distribution ◽  
Urban Drainage ◽  
Urban Water ◽  
Water Infrastructure ◽  
Urban Water Management ◽  
Drainage Systems ◽  
Urban Drainage Systems ◽  
Vulnerability Maps

One of the major tasks in urban water management is failure-free operation for at least most of the time. Accordingly, the reliability of the network systems in urban water management has a crucial role. The failure of a component in these systems impacts potable water distribution and urban drainage. Therefore, water distribution and urban drainage systems are categorized as critical infrastructure. Vulnerability is the degree to which a system is likely to experience harm induced by perturbation or stress. However, for risk assessment, we usually assume that events and failures are singular and independent, i.e. several simultaneous events and cascading events are unconsidered. Although failures can be causally linked, a simultaneous consideration in risk analysis is hardly considered. To close this gap, this work introduces the term cascade vulnerability for water infrastructure. Cascade vulnerability accounts for cascading and simultaneous events. Following this definition, cascade risk maps are a merger of hazard and cascade vulnerability maps. In this work cascade vulnerability maps for water distribution systems and urban drainage systems based on the ‘Achilles-Approach’ are introduced and discussed. It is shown, that neglecting cascading effects results in significant underestimation of risk scenarios.

Influence and modelling of urban runoff on the peak flows in rivers

2009 ◽  
Vol 60 (7) ◽  
pp. 1919-1927 ◽  
Author(s):  
G. Vaes ◽  
T. Feyaerts ◽  
P. Swartenbroekx
Keyword(s):  
Surface Waters ◽  
Drainage System ◽  
High Water ◽  
Water Levels ◽  
Urban Drainage ◽  
Combined Sewer Overflows ◽  
Drainage Systems ◽  
Simplified Approach ◽  
Urban Drainage Systems ◽  
Urban Catchments

Surface waters and urban drainage systems are usually studied separately. However there are important interactions between both systems. Urban drainage systems can have an important impact on the surface waters, mainly at combined sewer overflows. On the other hand during periods of high water levels in a river, the runoff from the urban drainage system can be significantly influenced by backwater, which increases the probability of flooding in is not obvious, because the modelling tools for both systems are often hard to combine properly. To properly assess the probability of flooding for this kind of integrated water systems, different submodels are needed for both subsystems. In practice often one single model is used to describe the runoff to rivers despite the presence of urban catchments. The main objective of this study is to show the limits of this simplified approach. Furthermore, it is necessary to use continuous long term simulations, because of the differences in runoff behaviour. Detailed hydrodynamic models do not really fit for this purpose because of long simulation times and high demands in memory and disk space. Therefore simplified conceptual models are more useful.

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