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Results from a project in cooperation with the Belgian National Grid Operator ELIA are presented in this paper. Starting from a set of 245 time series, each one corresponding to four years of measurements from a HVLV substation, individual modeling using Periodic Time Series yields satisfactory results for short-term forecasting or simulation purposes. In addition, we use the stationarity properties of the estimated models to identify typical daily customer profiles. As each one of the 245 substations can be represented by its unique daily profile, it is possible to cluster the 245 profiles in order to obtain a segmentation of the original sample in different classes of customer profiles. This methodology provides a unified framework for the forecasting and clustering problems. [ABSTRACT FROM AUTHOR]

Abstract: Recent observations show that the river Zenne (Belgium) remains well below the water quality goals stated by the European Union Water Framework Directive. An interuniversity, multidisciplinary research project was therefore launched to evaluate the effects of wastewater management plans on the ecological functioning of the river. To this end, different water quantity and quality processes had to be considered and modelled, e.g., the hydrology in the river basin, hydraulics in the river and sewers, erosion and sediment transport, faecal bacteria transport and decay. This paper considers the development of an Open Modelling Interface (OpenMI) based integrated model for the purpose of simulating the river's sediment dynamics. We used the Soil and Water Assessment Tool (SWAT) to model water and sediment fluxes from rural areas. The Storm Water Management Model (SWMM) was used to simulate the hydraulics of the river, canal, and sewer systems in urban catchments. New model codes for sediment transport and stream water temperature were developed to complement SWMM. The results show that the integrated sediment transport model reproduced the sediment concentrations in the river Zenne with ‘good’ to ‘satisfactory’ accuracy. We may therefore conclude that the OpenMI has been successfully implemented to integrate water quality models into a hydraulic one. While the OpenMI run-time data communication inflicted calculation time overhead, we found that the overhead was not significant with respect to the total run-time of the integrated model. [Copyright &y& Elsevier]

Abstract: During a storm in October 2002, wind induced ovalling vibrations were observed on several empty silos of a closely spaced group of eight by five thin-walled silos in the port of Antwerp (Belgium). To determine realistic dynamic wind loads and hence clarify the cause of the wind induced ovalling vibrations in the silo group, 2D URANS simulations are performed for seven angles of incidence between 0° and 90°. The emphasis in this paper is on the extensive verification and validation of the simulations to ascertain the accuracy of the numerical results. Subsequent analysis of the fluctuating wind pressures on the silo surfaces shows that ovalling oscillations of the eigenmodes with three and four circumferential wavelengths will be induced at the lee side of the silo group, corresponding to the lowest structural eigenfrequencies of the silos and the pattern of the visually detected vibrations during the 2002 storm. [Copyright &y& Elsevier]

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Abstract: In this paper the flood problem of the river Demer, a river located in Belgium, is discussed. First a simplified model of the Demer basin is derived based on the conceptual reservoir modeling concept. This model was calibrated to simulations results with a more detailed full hydrodynamic model. Afterwards, the focus is shifted to a nonlinear model predictive controller (NMPC) which is based on a new semi-condensed optimization procedure combined with a line search approach. Finally, simulations are performed based on historical data in which the NMPC is compared with the current control strategy used by the local water administration. Uncertainties are added to the rainfall predictions in order to assess the robustness of the NMPC. [Copyright &y& Elsevier]

Descriptions of biochemical conversion processes based on QUAL principles have been used widely. We chose the recently developed IWA RWQM1 principles to model in-stream conversion of water quality components due to its sound physical background. An engine (a simulator) based on the RWQM1 principles was integrated with three other engine components—hydrological (SWAT), hydraulic (SWMM) and stream water temperature—in the OpenMI interface. We applied the integrated model to the River Zenne, Belgium. The results indicate that the integrated model can simulate various water quality components with a wide range of accuracy, from “Unsatisfactory” to “Very Good”. However, we could not validate the model against each of the RWQM1 components as most of the components were not measured in traditional river monitoring programmes. [ABSTRACT FROM AUTHOR]

The Town Energy Balance (TEB) single-layer scheme is implemented in a numerical weather prediction model running operationally at ~4-km resolution. The primary question addressed is the ability of TEB to function at this relatively coarse resolution and, thus, assessing its potential use in an operational configuration to improve sensible weather performance over Belgium. For this effort, simulations with and without TEB are first evaluated against 2-m observations and wind above the urban canopy for two months (January and July 2010). The results show that promising improvements are achieved by introducing TEB. The 2-m temperature and 2-m relative humidity improve compared to measurements in urban areas. The comparison of wind speed and wind direction above the urban canopy indicates that the structure of the flow in urban areas is better reproduced with TEB. It was found that the implementation of TEB results in an increase in winter precipitation over urban areas and downwind from urban areas, but during the summer TEB tended to cause rainfall to be locally concentrated and the total accumulated precipitation decreased obviously. Results from a 36-h case study during a high heat day with inland sea-breeze penetration (8 July 2010) indicate that the model satisfactorily captured the penetration of the sea breeze. In particular during the day, the TEB run shows a delay in the sea-breeze evolution compared to the operational run. During the night the results indicate that even at this coarse resolution, TEB is able to correctly reproduce the intensity of the observed urban heat island (UHI) of Brussels. [ABSTRACT FROM AUTHOR]

A hydroelectric power plant (HPP) started operation in December 2002 on the River Lhomme, (mean annual flow: 1.78 m3 s−1; mean annual water temperature: 9.9°C). The new HPP bypasses the river over a length of 1.2 km. The minimum flow allowed in the bypassed section is currently fixed at 0.220 m3 s−1. Before the construction of the HPP, two contrasted 150-m-long reaches of the Lhomme were selected to estimate their total fish population abundance and to analyse their fish population dynamics. Electrofishing was carried out in each of these two reaches on 23 April 2002 in a natural flow situation to remove the fish. Other inventories were carried out in late April or early May in 2003, 2004, 2005 and 2006 in minimum flow conditions. The results revealed a prompt and severe decrease in the total fish biomass (up to 81% for grayling from 2002 to 2006) combined with severe changes in the fish community structure that were not observed in a reference site. The effects of the flow reduction varied considerably depending on the size of the individuals, the species concerned and their habitat availability, which was modelled using a classical physical habitat simulation (EVHA method). [ABSTRACT FROM AUTHOR]

Worldwide, river fragmentation is primarily responsible for the decline of populations of migrating fish. In particular, anadromous fish species, which necessarily migrate to fresh water to reproduce, are endangered since many are no longer able to reach their natural spawning sites. In addition, pollution of rivers effectively prevents upstream or downstream movements and blocks access to spawning grounds. This article investigates how poor water quality interferes with the life history cycle of twaite shad Alosa fallax fallax (Lacépède, 1803), an anadromous clupeid fish, in the watershed of River Scheldt, a heavily impacted environment in West Europe. We used two models based on known ecological and environmental information to explain past and present twaite shad distribution within the watershed and to make inferences about a future population recovery and juvenile habitat value. We demonstrated that historical spawning areas satisfy water quality conditions necessary to support spawning and successful development of early life history stages of the twaite shad. However, poor water quality conditions just upstream the freshwater–saltwater boundary still act as an effective migration barrier for upstream movement. As a consequence, spawning grounds are inaccessible and the population is dominated by seasonal adults occurring in the lower estuarine part of the watershed. This article provides testable and diagnostic information to the watershed management in that it identifies habitat and water quality requirements needed to support the expected recovery of an endangered anadromous fish population. [ABSTRACT FROM AUTHOR]