Grum, M.

Neve, S. L.

Rasmussen, Michael R.

Thorndahl, Søren Liedtke

English

    Aalborg UniversitetRadar Based Flow and Water Level Forecasting in Sewer Systemsa danish case studyThorndahl, Søren Liedtke; Rasmussen, Michael R.; Grum, M.; Neve, S. L.Publication date:2010Document VersionOgså kaldet Forlagets PDFLink to publication from Aalborg UniversityCitation for published version (APA):Thorndahl, S. L., Rasmussen, M. R., Grum, M., & Neve, S. L. (2010). Radar Based Flow and Water LevelForecasting in Sewer Systems: a danish case study. Poster præsenteret ved 8th International Workshop onPrecipitation in Urban Areas, St. Moritz, Schweiz.General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright ownersand it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.            ? Users may download and print one copy of any publication from the public portal for the purpose of private study or research.            ? You may not further distribute the material or use it for any profit-making activity or commercial gain            ? You may freely distribute the URL identifying the publication in the public portal ?Take down policyIf you believe that this document breaches copyright please contact us at vbn@aub.aau.dk providing details, and we will remove access tothe work immediately and investigate your claim.Downloaded from vbn.aau.dk on: November 29, 2020RADAR BASED FLOW AND WATER LEVEL FORECASTING IN SEWER SYSTEMSA DANISH CASE STUDY–IntroductionClimate changes and increased urbanization are causing flooding and increased pollution due todischarge of untreated storm and waste water during heavy rainfall. This environmental problem willResult exampleThe following figures present the observed and forecasted radar data from the City of Slagelse on Oct.28, 2009 at 13:00.The applied radar is located on Stevns approx. 50 km from Slagelse.most likely increase in the future and can be solved in two ways; either by reconstruction of sewersystems, by expanding basin volumes, pipe dimensions, and treatment facilities or by optimizing theexisting infrastructure. The present is an approach of the latter.By the use of weather radars, it is possible to measure and forecast the spatially distributed rainfall overan urban catchment. Applying the forecasted rain as input to a runoff model, it is possible to forecastflow at key points within the sewer system thereby improve the real time operation of the sewer and 0 60.81  28-Oct-2009 12:30:0028-Oct-2009 12:00:0028-Oct-2009 11:00:00,wastewater treatment system, and thus reduce the discharged combined sewer overflow volumes.mm/min> 6.01.850.570.180.020.0050.0010 0005 0 20 40 60 80 100 12000.20.4.R2 Observed rain Oct. 28, 2009, 13:00. Black dotmarks Slagelse City and the triangle marks the location of the Stevns (DMI) C-band Radar.Validation of the rain forecast..0.0002 Lead time (min)R  f C b d d  (l  i l ) d D t  i f t t anges o - an ra ars arge c rc es anX-band radars (small circles).a a n ras ruc ure.CasesThis project is a collaboration between Aalborg University, Denmark, Krüger Veolia Water, Denmark,and the seven Danish municipalities: Aalborg, Egedal, Hvidovre, Odense, Slagelse, Toender, and Aarhus.Some of the municipalities possess their own X-band radar while some use online C-band data fromthe Danish Meteorological Institute (DMI) Each municipality has chosen an urban catchment in whichForecasted rain, Oct. 28, 2009, 12:30 + 30 min.Forecasted rain, Oct. 28, 2009, 12:00 + 60 min.Forecasted rain, Oct. 28, 2009, 11:00 + 120 min.The presented figures shows a statiform rain event with moderate rain intensties The correlation.different types of observations are recorded and transmitted online to a server, e.g., flow, water level,pump discharge, overflow registration, etc.Aalborg University is in charge of radar data and rain gauge data collection, calibration, and rain forecastand Krüger, Veolia Water is in charge of the collection of in-sewer measurements and the flow/waterlevel forecasting..coeffeceints (R2) on the forecast (of the whole radar extent) are quite high on the short lead times, butobviously lower on the longer forecast. Convective storms are more difficult to forecast withsatisfactory results, which is why a new generation of the forecast algorithm is currently underdevelopement. The observed and simulated inlet flow to Slagelse Waste Water Treatment Plant(WWTP) are shown in the following figure on the same date as presented above. The divergencebetween model and observations is quite low.Radar calibration and forecastThe X-band radars apply an empirical relationship between reflectivity and rain intensity, and thus haveto be calibrated against rain gauges. In this project the X-band radars are calibrated statically over aperiod of time ranging from 1-12 months applying from 5 to 40 rain gauges (hindcast). The C-bandradars are calibrated using a standard Marshall-Palmer relationship. Moreover, in order to gain the mostreliable levels of rain intensity, the radar data is adjusted continuously (dynamically calibrated) using 2-5On-line on-line rain gauges for each radar.The rain forecast is based on the CO-TREC algorithm in which a vector field of the movement of therain is obtained. X-band radar data is forecasted with a lead time of 1 hour and the C-band radar datais forecasted 2 hours.applicationsExample of the web user interface for the Slagelse Municipality on Oct. 28, 2009. Gray areas mark the forecast.  Top: Time series of observed intet flow to Slagelse WWTP (blue), modelled flow (red), and observed outlet flow (green).  Bottom:  time series of rain intensity (observed by the Stevns  C-band radar) in the catchment of the WWTPRadar data and rain forecast:http://www vejrradardk/VBSS htmlGlobal vector:Correlation between two radar images, .ConclusionA radar based forecast of flow and/or water level is implemented on seven urban catchments inDenmark. It is demonstrated that rain can be forecasted successfully with a lead time of 1-2 hoursdepending on the type of radar, and furthermore the total lead time can be extended to 1.5-3.5 hours. . .Flow and water level dataand forecast:htt // d t 2 dkCO-TRECCorrelation between subsets of two radar images with constraints on direction and speed as well as temporal averagingTRECCorrelation between subsets of two radar imagesdue to the transportation time in the drainage system. Radar data is calibrated statically using historicaldata dynamically applying on-line rain gauges in real time. The simple flow routing model, WaterAspects,is calibrated against historical data, and continuously updated using online in-sewer measurements.Hereby, it is emplified to forecast flow and water levels in specific points of the drainage system, e.g.inlets to large detention basins or inlets to wastewater treatment plants.The system shows a large potential, e.g. in retaining water in detention basins in order to minimizeBandwidth C-band X-bandRange 240 km 60 kmS l l 2000  2000 500  500 Concept of the CO-TREC forecasting method.p: www.regnra ar.s ar .S. Thorndahl(1),  M.R. Rasmussen(2), M. Grum(3), and S.L. Neve(4) (1) A    f C  S  9000 A  ( @ )combined sewer overflow and loads on wastewater treatment plants, to switch between dry and wetweather operation in wastewater treatment plants, economical operation of pumps, etc. The system iscurrently running online and is tested for a year, until the spring of 2010.patia reso ution x m x mTemporal resolution 10 min. 5 min.Frequency 5.6 GHz 9.4 GhzWave length 5.0 cm 3.2 cmScanning strategy Multiple layers Continuous in one layerOwner/developer DMI Municipalities/DHIRunoff forecastThe runoff model applied in the study is the simple and non-physically based flow routing model,WaterAspects. Using the overall structure of the sewer system, a simple model are set up andalborg University, Department o ivil Engineering, ohngaardsholmsvej 57, alborg, Denmark st civil.aau.dk(2) Aalborg University, Department of Civil Engineering, Sohngaardsholmsvej 57, 9000 Aalborg, Denmark (mr@civil.aau.dk)(3)Krüger, VeoliaWater, Gladsaxevej 363, 2860 Søborg, Denmark (mg@kruger.dk)(4)Krüger, VeoliaWater, Indkildevej 6 C, 9210 Aalborg SØ, Denmark (snl@kruger.dk)Radar specifications.8th International workshop on precipitation in urban areas   - December 10-13, 2009, St. Moritz, Switzerlandinterrelated timeseries of rain and observations in the drainage system is then used to calibrate themodel. In order to make the most reliable forecast the model is continuously adjusted against real timemeasurements in the drainage system using a Bayesian update algorithm.

Radar Based Flow and Water Level Forecasting in Sewer Systems:a danish case study

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Radar Based Flow and Water Level Forecasting in Sewer Systems:a danish case study

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