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Dynamically reconfigurable district metered areas (DMAs) for discolouration risk management

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Title: Dynamically reconfigurable district metered areas (DMAs) for discolouration risk management
Authors: Armand, Hooman
Item Type: Thesis or dissertation
Abstract: In the UK, network sectorisation (DMAs) for leakage management is the driver of network topology. Water quality deteriorating mechanisms are kinetic in nature and hydraulic-dependent. Thus, the permanent closure of valves related to the sectorisation is expected to exacerbate these mechanisms. This impact has not been extensively studied and it remains uncertain. This thesis proposes a methodology to assess this impact by using surrogate hydraulic variables derived from an in-depth literature review and analysing the spatio-temporal distribution of historical discolouration complaints. By comparing and contrasting the characteristics of cohesive layers formed in WSNs with morphological and mechanical behaviour of biofilms, the role of biofilms in discolouration is identified and indicators to achieve and evaluate enhanced cleaning are discussed. Applying the proposed methodology to a large-scale case study of an operational network, comprised of 22 DMAs with various sizes, topologies, topographies, and number of boundary valves, showed that the sectorisation results in an increase in water age and decrease in flow velocity which are indicators of water quality deterioration and increased likelihood of discolouration incidents. To address the risk of water quality deterioration posed by DMAs, this thesis proposes a novel hybrid system of operation, DMAs with dynamic boundary, to enable water quality management whilst accounting for topological restrictions of DMA-based networks and without compromising the leakage detection functionality of DMAs. Three valve-scheduling controls are explored to increase the number of self-cleaning pipes within DMAs and reduce water age around the DMA boundaries by regulating the topology of DMAs and operation of control valves. Application of these controls also offers other advantages such as increasing the resilience of supply and reducing the time to respond to incidents. Further development and optimal frequency of the controls is subject to further understanding of accumulation processes and the spatio-temporal cleaning requirements within the networks.
Content Version: Open Access
Issue Date: Oct-2018
Date Awarded: Jun-2019
URI: http://hdl.handle.net/10044/1/70711
DOI: https://doi.org/10.25560/70711
Copyright Statement: Creative Commons Attribution NonCommercial Licence
Supervisor: Stoianov, Ivan
Graham, Nigel
Department: Civil and Environmental Engineering
Publisher: Imperial College London
Qualification Level: Doctoral
Qualification Name: Doctor of Philosophy (PhD)
Appears in Collections:Civil and Environmental Engineering PhD theses