scholarly journals Data assimilation in hydrodynamic models for system-wide soft sensing and sensor validation for urban drainage tunnels

2020 ◽  
Author(s):  
Rocco Palmitessa ◽  
Peter Steen Mikkelsen ◽  
Adrian W. K. Law ◽  
Morten Borup
Keyword(s):  
Data Assimilation ◽  
Linear Models ◽  
Computational Cost ◽  
Drainage System ◽  
Urban Drainage ◽  
Hydrodynamic Models ◽  
Soft Sensing ◽  
Sensor Validation ◽  
Uncertainty Estimates ◽  
Combined Sewer

Abstract Tunnels are increasingly used worldwide to expand the capacity of urban drainage systems, but they are difficult to monitor with sensors alone. This study enables soft sensing of urban drainage tunnels by assimilating water level observations into an ensemble of hydrodynamic models. Ensemble-based data assimilation is suitable for non-linear models and provides useful uncertainty estimates. To limit the computational cost, our proposed scheme restricts the assimilation and ensemble implementation to the tunnel and represents the surrounding drainage system deterministically. We applied the scheme to a combined sewer overflow tunnel in Copenhagen, Denmark, with two sensors 3.4 km apart. The downstream observations were assimilated, while those upstream were used for validation. The scheme was tuned using a high-intensity event and validated with a low-intensity one. In a third event, the scheme was able to provide soft sensing as well as identify errors in the upstream sensor with high confidence.

Hydrodynamic Water Quality Simulation - An Approximative Solution

1991 ◽  
Vol 24 (6) ◽  
pp. 157-163
Author(s):  
E. Ristenpart ◽  
D. Wittenberg
Keyword(s):  
Water Quality ◽  
Drainage System ◽  
Urban Drainage ◽  
Flow Conditions ◽  
Nonstationary Flow ◽  
Combined Sewer Overflows ◽  
Water Quality Simulation ◽  
Combined Sewer ◽  
Receiving Waters ◽  
The One

Impacts from combined sewer systems on receiving waters are heavily polluting a lot of small river ecosystems. A simulation model which can be used to predict the development of water quality after combined sewer overflows and other impacts from the urban drainage system has been developed. This model works with hydrodynamic flow calculation because it is applied in a system of small wetland creeks with nonstationary flow conditions. The numerical solution of the differential equations is described as well as calibration results. It is shown that water quality simulation based on the one-dimensional mass transport equation is possible for nonstationary flow conditions and is going to become very useful in urban drainage planning.

Effect of urban drainage on bioavailability of heavy metals in recipient

2007 ◽  
Vol 56 (9) ◽  
pp. 43-50 ◽  
Author(s):  
D. Kominkova ◽  
J. Nabelkova
Keyword(s):  
Heavy Metals ◽  
Fine Particles ◽  
Drainage System ◽  
Human Consumption ◽  
Urban Drainage ◽  
Combined Sewer Overflows ◽  
Potential Health ◽  
Potential Health Risk ◽  
Combined Sewer ◽  
Heavy Metals Bioavailability

Heavy metals comprise one of the most hazardous groups of pollutants entering the aquatic environment. Their behaviour and ecotoxicological effects are not well understood especially if they are occur as a mix of metals. Drawing on data from three Prague creeks, the paper illustrates changes in heavy metals bioavailability resulting from different environmental conditions and related differences in urban drainage types. Heavy metals in sediment from creeks impacted by stormwater drain discharges are more bioavailable and accumulate in organisms to higher concentrations than in organisms from creeks affected by combined sewer overflows. The results also show that bioassay levels of lead in fish from the creeks exceed acceptable concentrations for human consumption (EC 466/2001) and therefore represent a potential health risk for humans. The results demonstrate the importance of providing improved interception efficiency in the drainage system structures. In particular, a higher level of interception of fine particles is critical, because of their higher metal adsorption capacity than for coarser particles.

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.

scholarly journals Estimation of combined sewer overflow discharge: a software sensor approach based on local water level measurements

2016 ◽  
Vol 74 (11) ◽  
pp. 2683-2696 ◽  
Author(s):  
Malte Ahm ◽  
Søren Thorndahl ◽  
Jesper E. Nielsen ◽  
Michael R. Rasmussen
Keyword(s):  
Mass Balance ◽  
Water Level ◽  
Drainage System ◽  
Urban Drainage ◽  
Combined Sewer Overflow ◽  
Software Sensor ◽  
Flow Measurements ◽  
Combined Sewer ◽  
Sewer Overflow ◽  
Local Water

Combined sewer overflow (CSO) structures are constructed to effectively discharge excess water during heavy rainfall, to protect the urban drainage system from hydraulic overload. Consequently, most CSO structures are not constructed according to basic hydraulic principles for ideal measurement weirs. It can, therefore, be a challenge to quantify the discharges from CSOs. Quantification of CSO discharges are important in relation to the increased environmental awareness of the receiving water bodies. Furthermore, CSO discharge quantification is essential for closing the rainfall-runoff mass-balance in combined sewer catchments. A closed mass-balance is an advantage for calibration of all urban drainage models based on mass-balance principles. This study presents three different software sensor concepts based on local water level sensors, which can be used to estimate CSO discharge volumes from hydraulic complex CSO structures. The three concepts were tested and verified under real practical conditions. All three concepts were accurate when compared to electromagnetic flow measurements.

CSO Modelling Considering Moving Storms and Tipping Bucket Gauge Failures

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
M. Hochedlinger ◽  
W. Sprung ◽  
H. Kainz ◽  
K. König
Keyword(s):  
Hydrological Models ◽  
Rain Intensity ◽  
Hydrodynamic Models ◽  
Data Intensive ◽  
Storm Flow ◽  
Cell Velocity ◽  
Combined Sewer ◽  
Moving Direction ◽  
The Difference

The simulation of combined sewer overflow volumes and loads is important for the assessment of the overflow and overflow load to the receiving water to predict the hydraulic or the pollution impact. Hydrodynamic models are very data-intensive and time-consuming for long-term quality modelling. Hence, for long-term modelling, hydrological models are used to predict the storm flow in a fast way. However, in most cases, a constant rain intensity is used as load for the simulation, but in practice even for small catchments rain occurs in rain cells, which are not constant over the whole catchment area. This paper presents the results of quality modelling considering moving storms depending on the rain cell velocity and its moving direction. Additionally, tipping bucket gauge failures and different corrections are also taken into account. The results evidence the importance of these considerations for precipitation due the effects on overflow load and show the difference up to 28% of corrected and uncorrected data and of moving rain cells instead of constant raining intensities.

Comprehensive Planning of Urban Drainage and Wastewater Treatment

1993 ◽  
Vol 27 (12) ◽  
pp. 205-208
Author(s):  
Dirk-Th Kollatsch
Keyword(s):  
Wastewater Treatment ◽  
Transport Model ◽  
Drainage System ◽  
Simulation Models ◽  
Urban Drainage ◽  
Sewer Systems ◽  
Priority Task ◽  
Treatment Facilities ◽  
Receiving Waters ◽  
Pollution Impacts

For upgrading the urban drainage system (UDS) the reduction of pollution impacts is the priority task concerning the environmental protection of the receiving waters. With simulation models the interactions between surface, sewer systems, overflow structures and treatment facilities within the UDS can be shown. Models to simulate the pollutant impacts, transport and the effects on the receiving waters are available. In a first step a pollutant transport model of sewer systems and a model to simulate the wastewater treatment processes are connected. With these models the efficiency of upgrading measures can be checked in all parts of urban drainage systems.

Methods for studying dissolved oxygen levels in coastal and estuarine waters receiving combined sewer overflows

1995 ◽  
Vol 32 (2) ◽  
pp. 95-103
Author(s):  
José A. Revilla ◽  
Kalin N. Koev ◽  
Rafael Díaz ◽  
César Álvarez ◽  
Antonio Roldán
Keyword(s):  
Dissolved Oxygen ◽  
Coastal Waters ◽  
Computational Cost ◽  
Oxygen Deficit ◽  
Alternative Methods ◽  
Coastal Zones ◽  
Combined Sewer Overflows ◽  
Sewer Systems ◽  
Combined Sewer ◽  
High Computational Cost

One factor in determining the transport capacity of coastal interceptors in Combined Sewer Systems (CSS) is the reduction of Dissolved Oxygen (DO) in coastal waters originating from the overflows. The study of the evolution of DO in coastal zones is complex. The high computational cost of using mathematical models discriminates against the required probabilistic analysis being undertaken. Alternative methods, based on such mathematical modelling, employed in a limited number of cases, are therefore needed. In this paper two alternative methods are presented for the study of oxygen deficit resulting from overflows of CSS. In the first, statistical analyses focus on the causes of the deficit (the volume discharged). The second concentrates on the effects (the concentrations of oxygen in the sea). Both methods have been applied in a study of the coastal interceptor at Pasajes Estuary (Guipúzcoa, Spain) with similar results.

Comparison of the efficiency of best stormwater management practices in urban drainage systems

1999 ◽  
Vol 39 (9) ◽  
pp. 269-276 ◽  
Author(s):  
R. Mehler ◽  
M. W. Ostrowski
Keyword(s):  
Stormwater Management ◽  
Management Practices ◽  
Alternative Methods ◽  
Urban Drainage ◽  
Pollution Load ◽  
Load Model ◽  
Urban Stormwater Management ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Stormwater Management Practices

Increasingly extended and alternative methods for urban stormwater management have been discussed in Germany and elsewhere. Without question an economically and ecologically sound combination of central and decentral measures will be a concept of the future. Yet, at present the introduction of approaches other than traditional combined sewer systems is restricted due to missing planning tools and technologies. Adding a number of frequently used Best Stormwater Management Practices (BSMP's) has widely extended the applicability of an existing stormwater water balance and pollution load model.

A novel approach to the real-time modelling of large urban drainage systems

1997 ◽  
Vol 36 (8-9) ◽  
pp. 19-24 ◽  
Author(s):  
Richard Norreys ◽  
Ian Cluckie
Keyword(s):  
Real Time ◽  
Dynamic Models ◽  
Drainage System ◽  
Radar Data ◽  
Urban Drainage ◽  
Real Time Control ◽  
Empirical Modelling ◽  
Time Control ◽  
Novel Approach ◽  
Non Linear Systems

Conventional UDS models are mechanistic which though appropriate for design purposes are less well suited to real-time control because they are slow running, difficult to calibrate, difficult to re-calibrate in real time and have trouble handling noisy data. At Salford University a novel hybrid of dynamic and empirical modelling has been developed, to combine the speed of the empirical model with the ability to simulate complex and non-linear systems of the mechanistic/dynamic models. This paper details the ‘knowledge acquisition module’ software and how it has been applied to construct a model of a large urban drainage system. The paper goes on to detail how the model has been linked with real-time radar data inputs from the MARS c-band radar.

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