| dc.description.abstract | The performance of the Integrated Urban Wastewater Systems (IUWS)
including: sewer system, WWTP and river, in both operational control and
design, under unavoidable future climate change and urbanisation is a concern
for water engineers which still needs to be improved. Additionally, with regard to
the recent attention around the world to the environment, the quality of water, as
the main component of that, has received significant attention as it can have
impacts on health of human life, aquatic life and so on. Hence, the necessity of
improving systems performance under the future changes to maintain the
quality of water is observed. The research presented in this thesis describes the
development of risk-based and non-risk-based models to improve the
operational control and design of the IUWS under future climate change and
urbanisation aiming to maintain the quality of water in recipients.
In this thesis, impacts of climate change and urbanisation on the IUWS
performance in terms of the receiving water quality was investigated. In the line
with this, different indicators of climate change and urbanisation were selected
for evaluation.
Also the performance of the IUWS under future climate change and
urbanisation was improved by development of a novel non-risk-based
operational control and design models aiming to maintain the quality of water in
the river to meet the water quality standards in the recipient. This is initiated by
applying a scenario-based approach to describe the possible features of future
climate change and /or urbanisation.
Additionally the performance of the IUWS under future climate change and
urbanisation was improved by development of a novel risk-based operational
control and design models to reduce the risk of water quality failures to maintain
the health of aquatic life. This is initiated by considering the uncertainties
involved with the urbanisation parameters considered. The risk concept is
applied to estimate the risk of water quality breaches for the aquatic life.
Also due to the complexity and time-demanding nature of the IUWS simulation
models (which are called about the optimisation process), there is the concern
about excessive running times in this study. The novel “MOGA-ANNβ” algorithm
was developed for the optimisation process throughout the thesis to speed it up while preserving the accuracy. The meta-model developed was tested and its
performance was evaluated.
In this study, the results obtained from the impact analysis of the future climate
change and urbanisation (on the performance of the IUWS) showed that the
future conditions have potential to influence the performance of the IUWS in
both quality and quantity of water. In line with this, selecting proper future
conditions’ parameters is important for the system impact analysis. Also the
observations demonstrated that the system improvement is required under
future conditions. In line with this, the results showed that both risk-based and
non-risk-based operational control optimisation of the IUWS in isolation is not
good enough to cope with the future conditions and therefore the IUWS design
optimisation was carried out to improve the system performance. The riskbased
design improvement of the IUWS in this study showed a better potential
than the non-risk-based design improvement to meet all the water quality
criteria considered in this study. | en_GB |
