An agent-based approach for generating virtual sewer systems

2010 ◽  
Vol 62 (5) ◽  
pp. 1090-1097 ◽  
Author(s):  
C. Urich ◽  
R. Sitzenfrei ◽  
M. Möderl ◽  
W. Rauch
Keyword(s):  
Population Distribution ◽  
Automatic Generation ◽  
Data Sets ◽  
Urban Structure ◽  
Sewer System ◽  
Agent Based ◽  
Sewer Systems ◽  
Virtual Infrastructure ◽  
Sewer Networks

The application of artificial case studies is a well established technique in urban drainage to test measures, approaches or models. However, the preparation of a virtual case study for a sewer system is a tedious task. Several algorithms have been presented in the literature for an automatic generation of virtual sewer systems. Applying the approach of generating virtual cities by means of the software VIBe (Virtual Infrastructure Benchmarking) the urban structure (including elevation map, land use and population distribution) is generated firstly and the infrastructure is designed meeting the requirements of the urban structure. The aim of this paper is the development of an agent based approach for generating virtual sewer systems. This new algorithm functions as module of the software VIBe but can of course also be applied to a real city in order to get information on possible/optimal sewer placement. Here hundred virtual VIBe cities and for each twelve virtual sewer networks are generated and calibrated based on data of an alpine region. It is revealed that with the approach presented virtual sewer networks which are comparable with real world sewer networks can be generated. The agent based method provides data sets for benchmarking and allows case independent testing of new measures.

Sediment transport under dry weather conditions in a small sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 155-162
Author(s):  
Flemming Schlütter ◽  
Kjeld Schaarup-Jensen
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sewer System ◽  
Transport Models ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Initial Results

Increased knowledge of the processes which govern the transport of solids in sewers is necessary in order to develop more reliable and applicable sediment transport models for sewer systems. Proper validation of these are essential. For that purpose thorough field measurements are imperative. This paper renders initial results obtained in an ongoing case study of a Danish combined sewer system in Frejlev, a small town southwest of Aalborg, Denmark. Field data are presented concerning estimation of the sediment transport during dry weather. Finally, considerations on how to approach numerical modelling is made based on numerical simulations using MOUSE TRAP (DHI 1993).

Dynamic virtual infrastructure benchmarking: DynaVIBe

2010 ◽  
Vol 10 (4) ◽  
pp. 600-609 ◽  
Author(s):  
R. Sitzenfrei ◽  
S. Fach ◽  
M. Kleidorfer ◽  
C. Urich ◽  
W. Rauch
Keyword(s):  
Case Studies ◽  
Distribution Systems ◽  
Water Distribution ◽  
New Technologies ◽  
Study Data ◽  
Data Availability ◽  
Urban Structure ◽  
Real World Data ◽  
Virtual Infrastructure

In environmental engineering, identification of problems and their solutions as well as the identification of the relevant processes involved is often done by means of case study analyses. By researching the operation of urban drainage and water distribution systems, this methodology is suited to evaluate new technologies, strategies or measures with regard to their impact on the overall processes. However, data availability is often limited and data collection and the development of new models are both costly and time consuming. Hence, new technologies, strategies or measures can only be tested on a limited number of case studies. In several environmental disciplines a few virtual case studies have been manually developed to provide data for research tasks and these are repeatedly used in different research projects. Efforts have also been invested in tackling limited data availability with the algorithmic generation of virtual case studies having constant or varying boundary conditions. The data provided by such tools is nevertheless only available for a certain instance in time. With DynaVIBe (Dynamic Virtual Infrastructure Benchmarking), numerous virtual case studies are algorithmically generated with a temporal development of the urban structure (population and land use model) and infrastructure. This provides a methodology that allows for the analysis of future scenarios on a spatio-temporal city scale. By linking a population model with DynaVIBe's infrastructure models, socio-economics impacts on infrastructure and system coherences can be investigated. The problematic of limited case study data is solved by the algorithmic generation of an unlimited number of virtual case studies, which are dynamic over time. Additionally, this methodology can also be applied on real world data for probabilistic future scenario analysis.

Quantification of sewer system infiltration using δ18O hydrograph separation

2009 ◽  
Vol 60 (3) ◽  
pp. 727-735 ◽  
Author(s):  
V. Prigiobbe ◽  
M. Giulianelli
Keyword(s):  
Sampling Strategy ◽  
Infiltration Rate ◽  
Hydrograph Separation ◽  
Catchment Scale ◽  
Sewer System ◽  
Urban Catchment ◽  
Sewer Systems ◽  
Conservative Tracer ◽  
Effective Water ◽  
Sewer Networks

The infiltration of parasitical water into two sewer systems in Rome (Italy) was quantified during a dry weather period. Infiltration was estimated using the hydrograph separation method with two water components and δ18O as a conservative tracer. The two water components were groundwater, the possible source of parasitical water within the sewer, and drinking water discharged into the sewer system. This method was applied at an urban catchment scale in order to test the effective water-tightness of two different sewer networks. The sampling strategy was based on an uncertainty analysis and the errors have been propagated using Monte Carlo random sampling. Our field applications showed that the method can be applied easily and quickly, but the error in the estimated infiltration rate can be up to 20%. The estimated infiltration into the recent sewer in Torraccia is 14% and can be considered negligible given the precision of the method, while the old sewer in Infernetto has an estimated infiltration of 50%.

scholarly journals Detection of extraneous water ingress into the sewer system using tandem methods – a case study in Trondheim city

2019 ◽  
Vol 79 (2) ◽  
pp. 231-239 ◽  
Author(s):  
M. Beheshti ◽  
S. Sægrov
Keyword(s):  
Economic Consequences ◽  
Distributed Temperature Sensing ◽  
Sewer System ◽  
Water Ingress ◽  
Sewer Systems ◽  
Excess Water ◽  
Effective Reduction ◽  
First Time ◽  
Groundwater Infiltration

Abstract Infiltration and inflow (I/I) of extraneous water in separate sewer systems are serious concerns in urban water management for their environmental, social and economic consequences. Effective reduction of I/I requires knowing where excess water ingress and illicit connections are located. The present study focuses on I/I detection in the foul sewer network of a catchment in Trondheim, Norway, during a period without snowmelt or groundwater infiltration. Fiber-optic distributed temperature sensing (DTS) was used for the first time in Norway to detect I/I sources in tandem with closed-circuit television inspection (CCTV) and smoke testing. DTS was an accurate and feasible method for I/I detection, though it cannot identify exact types of failure and sources of I/I. Therefore, other complementary methods must be used, e.g. CCTV or smoke testing. However, CCTV was not completely useful in confirming the DTS results. This study provides practical insights for the rehabilitation and repair of sewer networks that suffer from the undesirable I/I of extraneous water.

Influence of characteristics on combined sewer performance

2012 ◽  
Vol 66 (5) ◽  
pp. 1052-1060 ◽  
Author(s):  
M. Möderl ◽  
M. Kleidorfer ◽  
W. Rauch
Keyword(s):  
Automatic Generation ◽  
Negative Influence ◽  
Positive Influence ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Different Characteristics ◽  
Further Development ◽  
Storage Units ◽  
System Characteristics

Elements of combined sewer systems are among others sub-catchments, junctions, conduits and weirs with or without storage units. The spatial distribution and attributes of all these elements influence both system characteristics and sewer performance. Until today, little work has been done to analyse the influence of such characteristics in a case unspecific approach. In this study, 250 virtual combined sewer systems are analysed by defining groups of systems, which are representative for their different characteristics. The set was created with a further development of the case study generator (CSG), a tool for automatic generation of branched sewer systems. Combined sewer overflow and flooding is evaluated using performance indicators based on hydrodynamic simulations. The analysis of system characteristics, like those presented in this paper, helps researchers to understand coherences and aids practitioners in designing combined sewers. For instance, it was found that characteristics that have a positive influence on emission reduction frequently have a negative influence on flooding avoidance and vice versa.

Probabilistic modeling of sewer deterioration using inspection data

2008 ◽  
Vol 57 (10) ◽  
pp. 1635-1641 ◽  
Author(s):  
J. Dirksen ◽  
F. H. L. R. Clemens
Keyword(s):  
Visual Inspection ◽  
Surface Damage ◽  
Mechanical Action ◽  
Sewer System ◽  
Sewer Systems ◽  
Historical Databases ◽  
Inspection Data ◽  
Need For Rehabilitation ◽  
Sewer Inspection

Accurate prediction of current and future conditions of sewer systems is crucial to manage the sewer system wisely, cost-effectively and efficiently. The application of historical databases of visual inspection data to sewer deterioration modeling seems common sense. However, in The Netherlands, sewer inspection data is only used to determine the direct need for rehabilitation. This paper outlines the possibilities of using inspection data for deterioration modeling and discusses the problems encountered. A case study was performed on the modeling of the condition aspect ‘surface damage by corrosion or mechanical action’ using a Markov model.

Infiltration in Sewer Systems: Multi-Criteria Comparison of Investment / Rehabilitation Strategies

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
J.-L. Bertrand-Krajewski ◽  
S. Barraud ◽  
P. Le Gauffre ◽  
E. Baer
Keyword(s):  
Investment Strategy ◽  
Final Decision ◽  
Specific Information ◽  
Sewer System ◽  
Site Specific ◽  
Infiltration Rates ◽  
Sewer Systems ◽  
Receiving Waters ◽  
Rehabilitation Strategies

Within the FP5 European APUSS project (Assessing infiltration and exfiltration on the Performance of Urban Sewer Systems), a methodology has been proposed to account for environmental, technical and economic impacts of infiltration or exfiltration on sewer systems, treatment plants and receiving waters, and to evaluate the consequences of possible investment / rehabilitation strategies. The multi-criteria method Electre III is used to compare and to rank the various strategies, as this method has a high potential adaptability to diverse contexts and objectives. An example of application of the proposed methodology is given for a 245 ha residential catchment equipped with a combined sewer system, including scenarios with different infiltration rates. It shows that the methodology is applicable, but also that validated and site specific information (data, measurements, calibrated models, etc.) is necessary in order to carry out a valuable analysis. Results shall be reviewed carefully and the final decision making process should take into account the context of the study. There is no unique best investment strategy, but several options may be considered depending on priorities and criteria of the sewer operator. The methodology is general, but results of the case study are site specific and cannot be extrapolated.

Design of self-cleansing sanitary sewer systems with the use of flushing devices

2009 ◽  
Vol 60 (4) ◽  
pp. 901-908 ◽  
Author(s):  
T. Goormans ◽  
D. Engelen ◽  
R. Bouteligier ◽  
P. Willems ◽  
J. Berlamont
Keyword(s):  
Surface Waters ◽  
Sewer System ◽  
Sewer Pipes ◽  
Hydrodynamic Simulations ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Increased Risk ◽  
Combined Sewer ◽  
Maintenance Requirements

Many European countries tend to shift from constructing combined sewer systems to separate ones, in order to optimise wastewater treatment efficiency and reduce CSO impact on surface waters. An economic design minimises maintenance requirements by aiming at self-cleansing pipes. However, providing the necessary slopes for self-cleansing sanitary sewer pipes often is unfeasible in flat regions, resulting in an increased risk of loss of hydraulic capacity or blocking. To reduce these risks, flushing tanks can be installed in the sewer system. Where most other researchers contribute to a better understanding of the hydraulics of flushing, this paper rather tries to formulate a methodology to design and test flushing devices in sanitary sewer systems using standards and hydrodynamic simulations. Therefore, several aspects that require consideration when incorporating flushing devices into a sanitary sewer system are discussed. For instance, when flushing sanitary sewers the increase in discharge has to be explicitly considered. A Belgian case study is used to investigate the suitability of the developed methodology. Although the pipe slopes in the methodology are derived assuming uniform flow, the simulation results comply with it. Furthermore, pressurisation of the conduits due to multiple flushing waves remains within acceptable limits.

scholarly journals Steady air flow model for large sewer networks: a theoretical framework

2020 ◽  
Author(s):  
Qi Zhang ◽  
Weiyun Shao ◽  
David Z. Zhu ◽  
Weilin Xu
Keyword(s):  
Driving Forces ◽  
Air Flow ◽  
General Idea ◽  
Sewer System ◽  
Flow Models ◽  
Closed Networks ◽  
Sewer Systems ◽  
Air Movement ◽  
System Data ◽  
Sewer Networks

Abstract Modelling air movement in sewer networks is needed in order to address the issues related to sewer odour complaints and sewer corrosions due to hydrogen sulphide in sewers. Most of the existing air flow models can only be applied in small sewer networks or the trunk lines of sewer systems. The purpose of this paper is therefore to propose a theoretical approach to formulate a general governing equation set for modelling steady air movement in large sewer systems. This approach decomposes the sewer system of interest into its basic physical components as pipes and nodes, and builds local topology of each pipe and each node based on geographic information system data as the fundamentals of model formulation. It avoids manually identifying each branch of the sewer system, eliminates the effect of physically closed networks in sewer systems on the governing equations, and considers key sewer components and all known driving forces. The proposed approach was applied to a real sewer system with over 500 pipes. The results show that the proposed model is applicable in modelling air movement in a large sewer system and provides a general idea of sewer gases moving through the system and their emission.

A conceptual model for sediment transport in combined sewer systems

1999 ◽  
Vol 39 (9) ◽  
pp. 39-46 ◽  
Author(s):  
Flemming Schlütter
Keyword(s):  
Sensitivity Analysis ◽  
Sediment Transport ◽  
Conceptual Model ◽  
Qualitative Information ◽  
Sewer System ◽  
Erosion And Deposition ◽  
Sewer Systems ◽  
Hydraulic Conditions ◽  
Combined Sewer

This paper presents a numerical model capable of simulating sediment transport in combined sewer systems. The main objectives of the model are to model mass transport rates at the outlet from a catchment and at the same time obtaining qualitative information on erosion and deposition going on at different locations in the sewer system. The model is conceptual but based on deterministic computations of hydraulic conditions. The formulations used in the conceptual model (STSim) are presented as well as results from a sensitivity analysis. Finally, an example is given of a calibration event from a case study.

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