1. General Model Information
Name: a stochastic software tool for assessing impacts of urban drainage on receiving waters
Acronym: REBEKA2
Main medium: aquatic
Main subject: hydrology, (eco)toxicology
Organization level: Ecosystem
Type of model: Monte Carlo simulation, other, difference equations (1D),
Main application: screening tool, research, simulation/optimisation tool
Keywords: Combined sewer overflow, model uncertainties, Monte Carlo simulation, receiving water, stochastic modelling, urban drainage
Contact:
Rolf Fankhauser
Fankhauser GEP Data Consulting, Murbacherstr.34,
CH-4056 Basel,
Switzerland
Phone: ++41-(0)61-321-20-91
Fax:
email: rolf.fankhauser@gepdata.ch
Author(s):
Rolf Fankhauser, Simon Kreikenbaum, Wolfgang Rauch, Luca Rossi, Vladimir Krejci
Abstract:
REBEKA is a software tool that has been developed to assess impacts of urban
drainage to receiving waters based on immission criteria. The program
calculates the average number of critical events per year for NH3 pollution
and riverbed erosion caused by urban storm water overflows for a given
catchment. It is already widely used by Swiss practitioners in processing the
receiving water status report of the master plan of urban drainage. REBEKA is
now extended to REBEKA II by (1) a stochastic model which simulates input,
transport and emission of total suspended solids (TSS) by the drainage system
and their immission in the receiving water and (2) by stochastic modelling in
general: each model parameter is treated as a random variable with a specific
mean value, variation and probability distribution. Different probability
distributions are available. The probability distribution of model outputs
(i.e. number of critical events for ammonia toxicity and riverbed erosion,
TSS lo!
ad and time of critical TSS immission) is calculated by means of a Monte Carlo
simulation. To determine the importance of the model parameters to the output
variables a local sensitivity analysis is implemented.
II. Technical Information
II.1 Executables:
Operating System(s): Windows
II.2 Source-code:
Programming Language(s): C++, Delphi
II.3 Manuals:
see: REKEKA Homepage
II.4 Data:
see: REKEKA Homepage
Necessary data:
- Combined sewer system (Inhabitants, impervious area, storage constant, initial loss, dry weather flow, NH 4 load, TSS concentration in wastewater etc.),
- separate sewer system (Impervious area, storage constant, initial lost, TSS concentration in rainwater etc.),
- natural catchment (Contributing area, initial loss, reservoir time constant),
- CSO tank (Type, volume, flow to WWTP, first flush coefficient, efficiency factor),
- receiving water (Baseflow, manning number, channel slope, channel width, scarp slope, average debris diameter, NH4 concentration, pH value, alkalinity, min. and max. temp., TSS settling velocity, erosion coefficient, degradation rate of org. matter in the river bed, critical shear stress etc.)
III. Mathematical Information
III.1 Mathematics
III.2 Quantities
III.2.1 Input
III.2.2 Output
IV. References
Rauch W., Krejci V. and Gujer W. (2002). REBEKA - a software tool for planning urban drainage on the basis of predicted impacts on receiving water. Urban Water, 4: 355-361.
Kreikenbaum S. Krejci V., Rauch W. and Rossi L. (2002). Probabilistic modeling as a new planning approach to stormwater management. 9th ICUD (International Conference on Urban Drainage), Portland (Oregon), USA.
Fankhauser R., Kreikenbaum S., Krejci V., Rossi L., Rauch W. (2004). Rebeka II – a stochastic software tool for assessing impacts of urban drainage on receiving waters. 6th Int. Conf. on Urban Drainage Modelling (UDM), pp. 175-184, Dresden, Germany
Rossi L., Krejci V., Rauch W., Kreikenbaum S., Fankhauser R. and Gujer W.(2005).Stochastic modeling of total suspended solids (TSS) in urban areas during rain events. Water Research 39(17):4188-4196
V. Further information in the World-Wide-Web
VI. Additional remarks
Last review of this document by: : Wed Feb 1 20:21:36 2006
Status of the document: Contributed by Rolf Fankhauser
last modified by
Joachim Benz Wed May 10 11:31:09 CEST 2006