Smart meter privacy by suprression of low power frequency components

This paper focuses on the problems associated with privacy protection in smart grid. We will give an overview of a possible realization of a privacy-preserving approach that encompasses privacy-utility tradeoff into a single model. This approach proposes suppression of low power frequency components as a solution to reduce the amount of information leakage from smart meter readings. We will consider the applicability of the procedure to hide the appliance usage with respect to the type of home devices

Analytical and numerical solutions of the Local Inertial Equations

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Neglecting the convective terms in the Saint-Venant Equations (SVE) in flood hydrodynamic modelling can be done without a loss in accuracy of the simulation results. In this case the Local Inertial Equations (LInE) are obtained. Herein we present two analytical solutions for the Local Inertial Equations. The first is the classical instantaneous Dam-Break Problem and the second a steady state solution over a bump. These solutions are compared with two numerical schemes, namely the first order Roe scheme and the second order MacCormack scheme. Comparison between analytical and numerical results shows that the numerical schemes and the analytical solution converge to a unique solution. Furthermore, by neglecting the convective terms the original numerical schemes remain stable without the need for adding entropy correction, artificial viscosity or special initial conditions, as in the case of the full SVE.This research is partially funded by the FCT (Portuguese Foundation for Science and Technology) through the Doctoral Grant SFRH/BD/81869/2011 financed through the POPH/FSE program (Programa Operacional Potencial Humano/Fundo Social Europeu). This study had the support of the Portuguese Foundation for Science and Technology (FCT) Project UID/MAR/04292/2013

Modelling sewer discharge via displacement of manhole covers during flood events using 1D/2D SIPSON/P-DWave dual drainage simulations

This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this recordIn urban areas, overloaded sewers may result in surcharge that causes surface flooding. The overflow from sewer systems mainly starts at the inlets until the pressure head in the manhole is high enough to lift up its cover, at which stage the surcharged flow may be discharged via the gap between the bottom of the manhole cover and the ground surface. In this paper, we propose a new approach to simulate such a dynamic between the sewer and the surface flow in coupled surface and sewer flow modelling. Two case studies are employed to demonstrate the differences between the new linking model and the traditional model that simplifies the process. The results show that the new approach is capable of describing the physical phenomena when manhole covers restrict the drainage flow from the surface to the sewer network and reduce the surcharge flow and vice versa.DFG (Deutsche Forschungsgemeinschaft

Early Warning System for Bathing Water Quality

Poster describing use of Artificial Neural Networks (ANN) in a Receiver-Operating Characteristic (ROC) scenario to predict bathing water quality exceedances at beaches in the SW UK.Environment Agency (SW

Rain Gauge and Radar Rainfall Information for Urban Flash Flood Analysis

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

The urban inundation model with bidirectional flow interaction between 2D overland surface and 1D sewer networks

8th international conference, Novatech 2013, Lyon, France, 23 – 27 June 2013An integrated numerical model is developed in the study for simulating the runoff processes in urban areas. A 1D model is used for calculating the rainfall-runoff hydrographs and the flow conditions in drainage networks. A 2D model is employed for routing flow on overland surface. Both models are solved by different numerical schemes and using different time steps with the flow through manholes adopted as model connections. The effluents and influents via manholes are determined by the weir or the orifice equations. Timing synchronisation between both models is taken into account to guarantee suitable model linkages.EPSRC: Engineering and Physical Sciences Research Counci

An analysis of the combined consequences of pluvial and fluvial flooding

Copyright © IWA Publishing 2010. The definitive peer-reviewed and edited version of this article is published in Water Science & Technology Vol. 62 No. 7 pp 1491–1498 (2010), DOI: 10.2166/wst.2010.486, and is available at www.iwapublishing.comIntense rainfall in urban areas often generates both pluvial flooding due to the limited capacity of drainage systems, as well as fluvial flooding caused by deluges from river channels. The concurrence of pluvial and fluvial flooding can aggravate their (individual) potential damages. To analyse the impact caused by individual and composite type of flooding, the SIPSON/UIM model, an integrated 1D sewer and 2D overland flow was applied to numerical modelling. An event matrix of possible pluvial scenarios was combined with hypothetic overtopping and breaching situations to estimate the surface flooding consequences in the Stockbridge area, Keighley (Bradford, UK). The modelling results identified different flooding drivers in different parts of the study area and showed that the worst scenarios resulted from synthesised events.Engineering and Physical Sciences Research Council (EPSRC

Multi-layered coarse grid modelling in 2D urban flood simulations

Copyright © 2012 Elsevier. NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Hydrology Vol. 470-471, DOI: 10.1016/j.jhydrol.2012.06.022Regular grids are commonly used in 2D flood modelling due to wide availability of terrain models and low pre-processing required for input preparation. Despite advances in both computing software and hardware, high resolution flood modelling remains computationally demanding when applied to a large study area when the available time and resources are limited. Traditional grid coarsening approach may reduce not only the computing demands, but also the accuracy of results due to the loss of detailed information. To keep key features that affect flow propagation within coarse grid, the approach proposed and tested in this paper adopts multiple layers in flood modelling to reflect individual flow paths separated by buildings within a coarse grid cell. The cell in each layer has its own parameters (elevation, roughness, building coverage ratio, and conveyance reduction factors) to describe itself and the conditions at boundaries with neighbourhood cells. Results of tests on the synthetic case study and the real world urban area show that the proposed multi-layered approach greatly improves the accuracy of coarse grid modelling with an insignificant additional computing cost. The proposed approach has been tested in conjunction with the UIM model by taking the high resolution results as the benchmark. The implementation of the proposed multi-layered methodology to any regular grid based 2D model would be straightforward

Analysis of extreme flooding events through a calibrated 1D/2D coupled model: the case of Barcelona (Spain)

This paper presents the results of a calibrated 1D/2D coupled model simulating surface and sewer flows in Barcelona. The model covers 44 km2 of the city land involving 241 km of sewers. It was developed in order to assess the flood hazard in the Raval district, historically affected by flooding during heavy rainfalls. Special attention was paid to the hydraulic characterization of the inlet systems (representing the interface between surface and underground flows), through experimental expressions used to estimate the effective runoff flows into the sewers in case of storms. A 2D unstructured mesh with more than 400,000 cells was created on the basis of a detailed digital terrain model. The model was calibrated and validated using four sets of well-recorded flooding events that occurred in 2011. The aim of this paper is to show how a detailed 1D/2D coupled model can be adequately calibrated and validated using a wide set of sewer sensors and post-event collected data (videos, photos, emergency reports, etc.). Moreover, the created model presents significant computational time savings via parallel processing and hardware configuration. Considering the computational performances achieved, the model can be used for real-time strategies and as the core of early warning systems.Peer ReviewedPostprint (author's final draft

Application of cellular automata approach for fast flood simulation

CCWI 2011: Computing and Control for the Water Industry, 5-7 September 2011, University of Exeter, UKThe increasing pluvial flooding in many urban areas of the world has caused tremendous damage to societies and has drawn the attention of researchers to the development of a fast flood inundation model. Most available models are based on solving a set of partial differential equations that require a huge computational effort. Researchers are increasingly interested in an alternative grid-based approach called Cellular Automata (CA), due to its computational efficiency (both with respect to time and computational cost) and inherent parallel nature. This paper deals with the computational experiment with a new CA method for modelling 2D pluvial flood propagation. A Digital Elevation Model (DEM) comprising square grids forms the discrete space for the CA setup. Local rules are applied in the von Neumann Neighbourhood for the spatio-temporal evolution of the flow field. The proposed model is applied to a hypothetical terrain to assess its performance. The results from the CA model are compared with those of a physically based 2D urban inundation model (UIM). The CA model results are comparable with the results from UIM model. The advantages of low computational cost of CA and its ability to mimic realistic fluid movement are combined in a novel and fast flood simulation model