Imperial College London

DR ANA MIJIC

Faculty of EngineeringDepartment of Civil and Environmental Engineering

Reader in Water Systems Integration
 
 
 
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Contact

 

+44 (0)20 7594 3796ana.mijic Website

 
 
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Assistant

 

Miss Judith Barritt +44 (0)20 7594 5967

 
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Location

 

310BSkempton BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

98 results found

Zhang Z, Dobson B, Moustakis Y, Meili N, Mijic A, Butler A, Athanasios Pet al., 2023, Assessing the co-benefits of urban greening coupled with rainwater harvesting management under current and future climates across USA cities, Environmental Research Letters, Vol: 18, ISSN: 1748-9318

Globally, urban areas face multiple challenges owing to climate change. Urban greening (UG) is an excellent option for mitigating flood risk and excess urban heat. Rainwater harvesting (RWH) systems can cope with plant irrigation needs and urban water management. In this study, we investigated how UG and RWH work together to mitigate environmental risks. By incorporating a new RWH module into the urban ecohydrological model Urban Tethys-Chloris (UT&C), we tested different uses of intervention approaches for 28 cities in the USA, spanning a variety of climates, population densities, and urban landscapes. UT&C was forced by the latest generation convection-permitting climate model simulations of the current (2001-2011) and end-of-century (RCP8.5) climate. Our results showed that neither UG nor RWH, through the irrigation of vegetation, could significantly contribute to mitigating the expected strong increase in 2 m urban canyon temperatures under a high-emission scenario. RWH alone can sufficiently offset the intensifying surface flood risk, effectively enhance water saving, and support UG to sustain a strong urban carbon sink, especially in dry regions. However, in these regions, RWH cannot fully fulfill plant water needs, and additional measures to meet irrigation demand are required to maximize carbon sequestration by urban vegetation.

Journal article

Tan Z, Berry A, Charalambides M, Mijic A, Pearse W, Porter A, Ryan M, Shorten R, Stettler M, Tetley T, Wright S, Masen Met al., 2023, Tyre wear particles are toxic for us and the environment

This briefing paper discusses the current knowledge on the effects of tyre wear particles on our health and environment, highlights the need for an ambitious research agenda to build further understanding of the impacts on people and nature and develop solutions, and includes recommendations for policymakers.

Report

Muhandes S, Dobson B, Mijic A, 2023, A method for adjusting design storm peakedness to reduce bias in hydraulic simulations, Proceedings of the Institution of Civil Engineers - Water Management, Vol: 176, Pages: 1-13, ISSN: 1741-7589

In the UK, decision makers use hydraulic model outputs to inform funding, connection consent, adoption of new drainage networks and planning application decisions. Current practice requires the application of design storms to calculate sewer catchment performance metrics such as flood volume, discharge rate and flood count. With flooding incidents occurring more frequently than their designs specify, hydraulic modelling outputs required by practice are questionable. The main focus of this paper is the peakedness factor (ratio of maximum to average rainfall intensity) of design storms, adjudging that this is a key contributor to model bias. Hydraulic models of two UK sewer catchments were simulated under historical storms, design storms and design storms with modified peakedness to test bias in modelling outputs and the effectiveness of peakedness modification in reducing bias. Sustainable drainage systems (Suds) were implemented at catchment scale and the betterment achieved in the modelling outputs was tested. The proposed design storm modification reduced the bias that occurs when driving hydraulic models using design storms in comparison with historical storms. It is concluded that Suds benefits are underestimated when using design rainfall because the synthetic rainfall shape prevents infiltration. Thus, Suds interventions cannot accurately be evaluated by design storms, modified or otherwise.

Journal article

Liu L, Dobson B, Mijic A, 2022, Optimisation of urban-rural nature-based solutions for integrated catchment water management, JOURNAL OF ENVIRONMENTAL MANAGEMENT, Vol: 329, ISSN: 0301-4797

Journal article

Dobson B, Barry S, Maes-Prior R, Mijic A, Woodward G, Pearse WDet al., 2022, Predicting catchment suitability for biodiversity at national scales, WATER RESEARCH, Vol: 221, ISSN: 0043-1354

Journal article

Puchol-Salort P, Boskovic S, Dobson B, van Reeuwijk M, Mijic Aet al., 2022, Water neutrality framework for systemic design of new urban developments, Water Research, Vol: 219, Pages: 1-13, ISSN: 0043-1354

The climate emergency and population growth threaten urban water security in cities worldwide. Growth, urbanisation, and changes to way of life have increased housing demand, requiring cities such as London to increase their housing stock by more than 15% over the next 10 years. These new urban developments will increase water demand, urban flood risk, and river water pollution levels; therefore, an integrated systems-based approach to development and water management is needed. Water Neutrality (WN) has emerged as a concept to frame the concerns about escalating water stresses in cities. We frame WN as a planning process for new urban developments that aims to minimise impacts on urban water security and offset any remaining stresses by retrofitting existing housing stock. In this work, we present a novel systemic design framework for future urban planning called CityPlan-Water, which guides how WN might be achieved to tackle current and future water pressures at a city scale. CityPlan-Water integrates spatial data with an integrated urban water management model, enabling urban design at a systems level and systematic assessment of future scenarios. We define a Water Neutrality Index that captures how successful a given urban planning scenario is in achieving WN and how multiple interventions could be combined at a city scale to improve WN. Results from CityPlan-Water suggest that it will be necessary to retrofit almost the same number of existing homes with WN design options to completely offset the impact imposed by proposed new developments. Combining options such as water efficient appliances, water reuse systems, and social awareness campaigns can offset the impact of new development on water demand by 70%, while to neutralise potential flood risk and water pollution at a city scale, interventions such as rainwater harvesting and Blue Green Infrastructure need to be added both in new urban developments and 432,000 existing London households. We see CityPlan-Wa

Journal article

Zhang Z, Paschalis A, Mijic A, Meili N, Manoli G, Van Reeuwijk M, Fatichi Set al., 2022, A mechanistic assessment of urban heat island intensities and drivers across climates, Urban Climate, Vol: 44, Pages: 1-18, ISSN: 2212-0955

The urban heat island effect (UHI) has been widely observed globally, causing climate,health, and energy impacts in cities. The UHI intensities have been found to largelydepend on background climate and the properties of the urban fabric. Yet, a completemechanistic understanding of how UHIs develop at a global scale is still missing. Usingan urban ecohydrological and land-surface model (urban Tethys-Chloris) incombination with multi-source remote sensing data, we performed simulations for 49large urban clusters across the Northern Hemisphere in 2009-2019 and analysed howsurface and canopy air UHIs (SUHI and CUHI, respectively) develop during day andnight. Biophysical drivers triggering the development of SUHIs and CUHIs have similardependencies on background climate, but with different magnitudes. In humid regionsdaytime UHIs can be largely explained by the urban-rural difference inevapotranspiration, whereas heat convection and conduction are important in aridareas. Plant irrigation can largely promote daytime urban evapotranspiration only inarid and semi-arid climates. During night, heat conduction from the urban fabric to theenvironment creates large UHIs mostly in warm arid regions. Overall, this studypresents a mechanistic quantification of how UHIs develop worldwide and proposesviable solutions for sustainable climate-sensitive mitigation strategies.

Journal article

O'Keeffe J, Pluchinotta I, De Stercke S, Hinson C, Puchol-Salort P, Mijic A, Zimmermann N, Collins AMet al., 2022, Evaluating natural capital performance of urban development through system dynamics: A case study from London., Science of the Total Environment, Vol: 824, Pages: 1-12, ISSN: 0048-9697

Natural capital plays a central role in urban functioning, reducing flooding, mitigating urban heat island effects, reducing air pollution, and improving urban biodiversity through provision of habitat space. There is also evidence on the role played by blue and green space in improving physical and mental health, reducing the burden on the health care service. Yet from an urban planning and development view, natural capital may be considered a nice to have, but not essential element of urban design; taking up valuable space which could otherwise be used for traditional built environment uses. While urban natural capital is largely recognised as a positive element, its benefits are difficult to measure both in space and time, making its inclusion in urban (re)development difficult to justify. Here, using a London case study and information provided by key stakeholders, we present a system dynamics (SD) modelling framework to assess the natural capital performance of development and aid design evaluation. A headline indicator: Natural Space Performance, is used to evaluate the capacity of natural space to provide ecosystem services, providing a semi-quantitative measure of system wide impacts of change within a combined natural, built and social system. We demonstrate the capacity of the model to explore how combined or individual changes in development design can affect natural capital and the provision of ecosystem services, for example, biodiversity or flood risk. By evaluating natural capital and ecosystem services over time, greater justification for their inclusion in planning and development can be derived, providing support for increased blue and green space within cities, improving urban sustainability and enhancing quality of life. Furthermore, the application of a SD approach captures key interactions between variables over time, showing system evolution while highlighting intervention opportunities.

Journal article

Fan PY, Chun KP, Mijic A, Tan ML, Yetemen Oet al., 2022, Integrating the Budyko framework with the emerging hot spot analysis in local land use planning for regulating surface evapotranspiration ratio, JOURNAL OF ENVIRONMENTAL MANAGEMENT, Vol: 316, ISSN: 0301-4797

Journal article

CIWEM, 2022, River water quality and storm overflows A systems approach to maximising improvement

his report presents the findings of research involving stakeholder engagement, systems mapping and policy and regulatory analysis around the issue of sewage pollution from storm overflows.It considers the challenges in their widest context, understanding where certain action should be driven by significant actors in the system and factors which combine to create the current situation, but can be considerably enhanced though action in a range of other complementary areas. The report’s focus is on England, but the principles discussed apply to greater or lesser extents to the devolved nations of the UK, as well as internationally.

Report

Dobson B, Barry S, Maes-Prior R, Mijic A, Woodward G, Pearse WDet al., 2022, Predicting catchment suitability for biodiversity at national scales

<jats:title>Abstract</jats:title><jats:p>Biomonitoring of water quality and catchment management are often disconnected, due to mismatching scales. Great effort and money is spent each year on routine reach-scale surveying across many sites, particularly in the UK, and typically with a focus on pre-defined indicators of organic pollution to compare observed vs expected subsets of common macroinvertebrate indicator species. Threatened species are often ignored due to their rarity as are many invasive species, which are seen as undesirable even though they are increasingly common in freshwaters, especially in urban ecosystems. However, these taxa are monitored separately for reasons related to biodiversity concerns rather than for gauging water quality. Repurposing such monitoring data could therefore provide important new biomonitoring tools that can help catchment managers to directly link the water quality that they aim to control with the biodiversity that they are trying to protect. Here we used the England Non-Native and Rare/Protected species records that track these two groups of species as a proof-of-concept for linking catchment scale management of freshwater ecosystems and biodiversity to a range of potential drivers across England. We used national land use (Centre for Ecology and Hydrology land cover map) and water quality indicator (Environment Agency water quality data archive) datasets to predict the presence or absence of 48 focal threatened or invasive species of concern routinely sampled by the English Environment Agency at catchment scale, with a median accuracy of 0.81 area under the receiver operating characteristic curve. A variety of water quality indicators and land-use types were useful in predictions, highlighting that future biomonitoring schemes could use such complementary measures to capture a wider spectrum of drivers and responses. In particular, the percentage of a catchment covered by freshwater was the single most

Journal article

Hinson C, O'Keeffe J, Mijic A, Bryden J, Van Grootveld J, Collins AMet al., 2022, Using natural capital and ecosystem services to facilitate participatory environmental decision making: Results from a systematic map, PEOPLE AND NATURE, Vol: 4, Pages: 652-668

Journal article

Fan PY, Chun KP, Mijic A, Tan ML, Liu MS, Yetemen Oet al., 2022, A framework to evaluate the accessibility, visibility, and intelligibility of green-blue spaces (GBSs) related to pedestrian movement, Urban Forestry & Urban Greening, Vol: 69, Pages: 1-16, ISSN: 1618-8667

The planning of green-blue spaces (GBSs) requires considering the pedestrian needs in their walking routes for improving the walking experience. Incorporating the quantitative spatial characteristics of pedestrian movement is essential for pedestrian-friendly urban planning, which however received insufficient attention. Based on the space syntax theory, this study provided three indicators – accessibility, visibility, and intelligibility – to demonstrate the needs of physical access, visual access, and spatial cognition, respectively, in pedestrian movement. Measuring these three indicators, this study exemplified the planning of pedestrian-friendly GBSs using Guangzhou, China as a case study. Spatial design network analysis was used to quantify heterogeneous values of accessibility, visibility, and intelligibility of each GBS throughout the city. Moreover, we used principal component analysis to identify the leading indicators based on their weightings and then to calculate the scores to compare these three aspects of GBSs. The measurements of accessibility, visibility, and intelligibility of each GBS were then averaged across urban administrative districts for evaluating city-scale GBSs. The findings showed that GBSs in central districts were most accessible and visible but least intelligible. In contrast, the overall intelligibility of GBSs throughout the city was the greatest but the visibility was the least. Furthermore, intelligibility, as a more important factor than accessibility and visibility, should be particularly emphasized in future planning of pedestrian-friendly GBSs. Pedestrians from the central districts of Guangzhou city were most satisfied with the walking experience, in terms of accessing to, viewing, and cognizing the GBSs. ‘Yuexiu’, ‘Huadu’, and ‘Nansha’ districts were found as the key places where improved accessibility, visibility, and intelligibility were particularly needed to improve the GB

Journal article

Liu L, Dobson B, Mijic A, 2022, Hierarchical systems integration for coordinated urban-rural water quality management at a catchment scale., Science of the Total Environment, Vol: 806, Pages: 1-12, ISSN: 0048-9697

Managing river quality is important for sustainable catchment development. In this study, we present how catchment management strategies benefit from a coordinated implementation of measures that are based on understanding key drivers of pollution. We develop a modelling approach that integrates environmental impacts, human activities, and management measures as three hierarchical levels. We present a catchment water management model (CatchWat) that achieves all three hierarchical levels and is applied to the Cherwell Catchment, UK. CatchWat simulations are evaluated against observed river flow and pollutant data including suspended solids, total nitrogen, and total phosphorus. We compare three competing hypotheses, or framings, of the catchment representation (integrated, urban-only, and rural-only framings) to test the impacts of model boundaries on river water quality modelling. Scenarios are formulated to simulate separate, combined and coordinated implementation of fertiliser application reduction and enhanced wastewater treatment. Results show that models must represent both urban and rural pollution emissions to accurately estimate river quality. Agricultural activities are found to drive river quality in wet periods because runoff is the main pathway for rural pollutants. Meanwhile, urban activities are the key source of pollution in dry periods because effluent constitutes a larger percentage of river flow during this time. Based on this understanding, we identify a coordinated management strategy that implements fertiliser reduction measures to improve river quality during wet periods and enhanced wastewater treatment to improve river quality during dry periods. The coordinated strategy performs comparably to the combined strategy but with higher overall efficiency. This study emphasises the importance of systems boundaries in integrated water quality modelling and simulating the mechanisms of seasonal water quality behaviour. Our key recommendation is tha

Journal article

Muhadi NA, Abdullah AF, Bejo SK, Mahadi MR, Mijic Aet al., 2022, Water level fluctuation using surveillance camera, International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives, Vol: 46, Pages: 257-260, ISSN: 1682-1750

Floods are the most frequent type of natural disaster that cause loss of life and damages to personal property and eventually affect the economic state of the country. Researchers around the world have been made significant efforts in dealing with the flood issue. Computer vision is one of the common approaches being employed which include the use of image segmentation techniques for image understanding and image analysis. The technique has been used in various fields including in flood disaster applications. This paper explores the use of a hybrid segmentation technique in detecting water regions from surveillance images and introduces a flood index calculation to study water level fluctuations. The flood index was evaluated by comparing the result with water level measured by sensor on-site. The experimental results demonstrated that the flood index reflects the trend of water levels of the river. Thus, the proposed technique can be used in detecting water regions and monitoring the water level fluctuation of the river.

Journal article

Dobson B, WatsonHill H, Muhandes S, Borup M, Mijic Aet al., 2022, A reduced complexity model with graph partitioning for rapid hydraulic assessment of sewer networks, Water Resources Research, Vol: 58, Pages: 1-21, ISSN: 0043-1397

Existing, high-fidelity models for sewer network modelling are accurate but too slow and inflexible for modern applications such as optimisation or scenario analysis. Reduced complexity surrogate modelling has been applied in response to this, however, current approaches are expensive to set up and still require high-fidelity simulations to derive parameters. In this study, we compare and develop graph partitioning algorithms to automatically group sections of sewer networks into semi-distributed compartments. These compartments can then be simulated using sewer network information only in the integrated modelling framework, CityWat-SemiDistributed (CWSD), which has been developed for application to sewer network modelling in this study. We find that combining graph partitioning with CWSD can produce accurate simulations 100-1,000x faster than existing high-fidelity modelling. Because we anticipate that many CWSD users will not have high-fidelity models available, we demonstrate that the approach provides reasonable simulations even under significant parametric uncertainty through a sensitivity analysis. We compare multiple graph partitioning techniques enabling users to specify the spatial aggregation of the partitioned network, also enabling them to preserve key locations for simulation. We test the impact of temporal resolution, finding that accurate simulations can be produced with timesteps up to one hour. Our experiments show a log-log relationship between temporal/spatial resolution and simulation time, enabling users to pre-specify the efficiency and accuracy needed for their applications. We expect that the efficiency and flexibility of our approach may facilitate novel applications of sewer network models ranging from continuous simulations for long-term planning to spatially optimising the placement of network sensors.

Journal article

Muhandes S, Dobson B, Mijic A, 2022, The value of aggregated city scale models to rapidly assess SuDS in combined sewer systems, Frontiers in Water, Vol: 3, Pages: 1-12, ISSN: 2624-9375

The role of Sustainable Drainage Systems (SuDS) in reducing combined sewer overflows (CSOs) and flood volumes can be accurately assessed using the available high-fidelity sewer network modelling software packages in the market. However, these tools are too slow for a range of modern applications such as optimisation or uncertainty analysis where long-term climate projection simulations are required. In this study, we create a novel representation of combined sewer systems to enhance an existing spatially aggregated model (CityWat) with additional functionalities to assess flood volumes, discharge to rivers and CSOs. We validate the developed model (CityWatStorm) by comparing the simulation results with a high-fidelity InfoWorks ICM model. Finally, we implement SuDS at a city scale and assess the betterment achieved in the context of flood volumes and CSOs. We conclude that CityWatStorm is able to capture the SuDS betterment within 95% accuracy, the total flood volume and CSOs within an accuracy ranging from 78% to 83%. This makes the aggregated model suitable for a wide range of applications such as sensitivity analysis of catchment interventions for long-term planning under future uncertainties.

Journal article

Fan PY, Chun KP, Mijic A, Mah DN-Y, He Q, Choi B, Lam CKC, Yetemen Oet al., 2021, Spatially-heterogeneous impacts of surface characteristics on urban thermal environment, a case of the Guangdong-Hong Kong-Macau Greater Bay Area, URBAN CLIMATE, Vol: 41, ISSN: 2212-0955

Journal article

Puchol-Salort P, Lu J, Boskovic S, Mijic A, Dobson B, van Reeuwijk Met al., 2021, Urban water neutrality at different scales: CityPlan design and evaluation framework, egu proceedings

<jats:p>&amp;lt;p&amp;gt;London aims to build more than half a million households over the next 10 years to cope with the growing demand for housing in the UK. In this future scenario, urban water security levels will be threatened due to new development pressures combined with the climate emergency and exponential population growth in the city. In addition to this, there is a lack of agreement between the policy and decision-making sectors to decide what can be accepted as a sustainable urban development project and which are the physical and decision boundaries inside the city (i.e., while boroughs and wastewater zones present decision boundaries, new urban developments have physical boundaries only). In our previous work, we developed a new concept for urban Water Neutrality (WN) inside an operational framework called CityPlan to frame the concerns about rising water stresses in cities. This framework integrates spatial data with an integrated urban water management model, enabling urban design at systems level and delivering a new index that assesses possible future scenarios. Despite several studies related to WN, little evidence is yet available in the literature of how urban water neutrality can be achieved at different urban scales and if results might vary depending on the scale studied.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;In this work, we expand the CityPlan framework and present an innovative evaluation approach that sets several urban indicators to be tested at different urban scales. As part of the evaluation toolkit of CityPlan, we also develop the Water Efficiency Certificate (WEC) by boroughs using two novel criteria: the Housing Age Indicator (HAI) and the Device Efficiency Score (DES). The WEC evaluates the current situation of household water consumption and can be used to support predictions of water consumption under different scenarios, to study the potential for retrofitting existing residential buildings, and to de

Journal article

Puchol-Salort P, Mijic A, van Reeuwijk M, Boskovic S, Dobson Bet al., 2021, Urban Water Neutrality at City Scale: CityPlan Evaluation and Design Module, Earth and Space Science Open Archive

Journal article

Mijic A, Whyte J, Myers R, Angeloudis P, Cardin M-A, Stettler M, Ochieng Wet al., 2021, Reply to a discussion of 'a research agenda on systems approaches to infrastructure' by david elms, Civil Engineering and Environmental Systems: decision making and problem solving, Vol: 38, Pages: 295-297, ISSN: 0263-0257

Journal article

Muhadi NA, Abdullah AF, Bejo SK, Mahadi MR, Mijic Aet al., 2021, Deep Learning Semantic Segmentation for Water Level Estimation Using Surveillance Camera, APPLIED SCIENCES-BASEL, Vol: 11

Journal article

Fan PY, Chun KP, Mijic A, Tan ML, He Q, Yetemen Oet al., 2021, Quantifying land use heterogeneity on drought conditions for mitigation strategies development in the Dongjiang River Basin, China, Ecological Indicators, Vol: 129, Pages: 1-13, ISSN: 1470-160X

Spatially-invariant land use and cover changes (LUCC) are not suitable for managing non-stationary drought conditions. Therefore, developing a spatially varying framework for managing land resources is necessary. In this study, the Dongjiang River Basin in South China is used to exemplify the significance of spatial heterogeneity in land planning optimization for mitigating drought risks. Using ERA5 that is the 5th major atmospheric reanalysis from the European Centre for Medium-Range Weather Forecast, we computed the Standardized Runoff Index (SRI) to quantify the hydrologic drought during 1992 to 2018. Also, based on Climate Change Initiative land use product, The Geographically Weighted Principal Component Analysis was used to identify the most dominant land types in the same period. Then, we used the Emerging Hot Spots Analysis to characterize the spatiotemporal evolution of historical LUCC and SRI. The spatially varying coefficients of Geographically and Temporally Weighted Regression models were used to reveal the empirical relationships between land types and the SRI. Results indicated that rainfed cropland with herbaceous cover, mosaic tress and shrub, shrubland, and grassland were four land types having statistical correlations with drought conditions over 27 years. Moreover, since 2003, the DRB was becoming drier, and the northern areas generally experienced severer hydrologic drought than the south. More importantly, we proposed region-specific land-use strategies for drought risk reductions. At a basin scale, we recommended to 1) increase rainfed herbaceous cropland and 2) reduce mosaic tree and shrub. At a sub-basin scale, the extents of shrub and grassland were suggested to increase in the northern DRB but to reduce in the south. Region-specific land use planning, including suitable locations, scales, and strategies, will contribute to handling current ‘one-size-fits-all’ LUCC. Planners are suggested to integrate spatial characteristics int

Journal article

Zhang Z, Paschalis A, Mijic A, 2021, Planning London’s green spaces in an integrated water management approach to enhance future resilience in urban stormwater control, Journal of Hydrology, Vol: 597, ISSN: 0022-1694

Vegetation, as a fundamental element of urban green infrastructure, plays a vital role in mitigating urban flooding. Green infrastructure performance in mitigating floods depends on plant responses to meteorological forcing. This puts urban green infrastructure in risk under a changing climate. In this study, the resilience and efficiency of London’s green infrastructure under climate change is evaluated. The coupled water and carbon dynamics were evaluated using a mechanistic ecohydrological model forced with the new generation of 2018 UK Climate Projections (UKCP18).It was found that despite overall reductions of runoff production in London under climate change in winter/autumn, current urban green infrastructure in London can lose its efficiency due to the elevated levels of plant water stress unless it operates in an integrated manner with the traditional grey infrastructure drainage system. Plant water stress induced mostly by changes in climate is expected to limit vegetation performance during the end of growing seasons. The negative effects of varying climatic factors on vegetation dynamics can only be partially alleviated by the positive effects of the elevated CO2 concentration level, and are highly uncertain due to the large uncertainty of climate projections.

Journal article

Mijic A, 2021, Systems water management for catchment scale processes

Report

Dobson B, Jovanovic T, Chen Y, Paschalis A, Butler A, Mijic Aet al., 2021, Integrated modelling to support analysis of COVID-19 impacts on London's water system and in-river water quality, Frontiers in Water, Vol: 3, Pages: 1-18, ISSN: 2624-9375

Due to the COVID-19 pandemic, citizens of the United Kingdom were required to stay at home for many months in 2020. In the weeks before and months following lockdown, including when it was not being enforced, citizens were advised to stay at home where possible. As a result, in a megacity such as London, where long-distance commuting is common, spatial and temporal changes to patterns of water demand are inevitable. This, in turn, may change where people’s waste is treated and ultimately impact the in-river quality of effluent receiving waters. To assess large scale impacts, such as COVID-19, at the city scale, an integrated modelling approach that captures everything between households and rivers is needed. A framework to achieve this is presented in this study and used to explore changes in water use and the associated impacts on wastewater treatment and in-river quality as a result of government and societal responses to COVID-19. Our modelling results revealed significant changes to household water consumption under a range of impact scenarios, however, they only showed significant impacts on pollutant concentrations in household wastewater were in central London. Pollutant concentrations in rivers simulated by the model were most sensitive in the tributaries of the River Thames, highlighting the vulnerability of smaller rivers and the important role that they play in diluting pollution. Modelled ammonia and phosphates were found to be the pollutants that rivers were most sensitive to because their main source in urban rivers is domestic wastewater that was significantly altered during the imposed mobility restrictions. A model evaluation showed that we can accurately validate individual model components (i.e., water demand generator) and 30emphasised need for continuous water quality measurements. Ultimately, the work provides a basis for further developments of water systems integration approaches to project changes under never-before seen scenarios.

Journal article

Mijic A, Whyte J, Fisk D, Angeloudis P, Ochieng W, Cardin M-A, Mosca L, Simpson C, McCann J, Stoianov I, Myers R, Stettler Met al., 2021, The Centre for Systems Engineering and Innovation – 2030 vision and 10-year celebration

The 2030 vision of the Centre is to bring Systems Engineering and Innovation to Civil Infrastructure by changing how cross-sector infrastructure challenges are addressedin an integrated way using principles of systems engineering to maximise resilience, safety and sustainability in an increasingly complex world.We want to better understand the environmental and societal impacts of infrastructure interventions under uncertainty. This requires a change in current approaches to infrastructure systems engineering: starting from the natural environmentand its resources, encompassing societaluse of infrastructure and the supporting infrastructure assets and services.We argue for modelling that brings natural as well as built environments within the system boundaries to better understand infrastructure and to better assess sustainability. We seethe work as relevant to both the academic community and to a wide range of industry and policy applications that are working on infrastructure transition pathways towards fair, safe and sustainable society.This vision was developed through discussions between academics in preparation for the Centre for Systems Engineering and Innovation (CSEI) 10 years celebration. These rich discussions about the future of the Centre were inspired by developing themes for a celebration event, through which we have summarised the first 10 years of the Centre’s work and our vision for the future and identified six emerging research areas.

Report

Puchol-Salort P, OKeeffe J, van Reeuwijk M, Mijic Aet al., 2021, An urban planning sustainability framework: systems approach to blue green urban design, Sustainable Cities and Society, Vol: 66, Pages: 1-14, ISSN: 2210-6707

The climate emergency and population growth are challenging water security and sustainable urban design in cities worldwide. Sustainable urban development is crucial to minimise pressures on the natural environment and on existing urban infrastructure systems, including water, energy, and land. These pressures are particularly evident in London, which is considered highly vulnerable to water shortages and floods and where there has been a historical shortage of housing. However, the impacts of urban growth on environmental management and protection are complex and difficult to evaluate. In addition, there is a disconnection between the policy and decision-making processes as to what comprises a sustainable urban development project.We present a systems-based Urban Planning Sustainability Framework (UPSUF) that integrates sustainability evaluation, design solutions and planning system process. One of the features of this master planning framework is the spatial representation of the urban development in a Geographical Information System to create an operational link between design solutions and evaluation metrics. UPSUF moves from an initial baseline scenario to a sustainable urban development design, incorporating the requirements of governance and regulatory bodies, as well as those of the end-users. Ultimately, UPSUF has the potential to facilitate partnership between the public and the private sectors.

Journal article

Whyte J, Mijic A, Myers RJ, Angeloudis P, Cardin M, Stettler M, Ochieng Wet al., 2020, A research agenda on systems approaches to infrastructure, Journal of Civil Engineering and Environmental Systems, Vol: 37, Pages: 214-233, ISSN: 1029-0249

At a time of system shocks, significant underlying challenges are revealed in current approaches to delivering infrastructure, including that infrastructure users in many societies feel distant from nature. We set out a research agenda on systems approaches to infrastructure, drawing on ten years of interdisciplinary work on operating infrastructure, infrastructure interventions and lifecycles. Research insights and directions on complexity, systems integration, data-driven systems engineering, infrastructure life-cycles, and the transition towards zero pollution are summarised. This work identifies a need to better understand the natural and societal impacts of infrastructure interventions under uncertainty. We argue for a change in current approaches to infrastructure: starting from the natural environment and its resources, encompassing societal use of infrastructure and the supporting infrastructure assets and services. To support such proposed new systems approaches to infrastructure, researchers need to develop novel modelling methods, forms of model integration, and multi-criteria indicators.

Journal article

De Stercke S, Chaturvedi V, Buytaert W, Mijic Aet al., 2020, Water-energy nexus-based scenario analysis for sustainable development of Mumbai, Environmental Modelling and Software, Vol: 134, Pages: 1-17, ISSN: 1364-8152

The urban water-energy nexus sits at the intersection of the global phenomena of water scarcity, energy transitions and urbanisation. Research found that end use dominates the waterenergy nexus and that this component plays an important role in urban dynamics, but focussed on the Global North. We investigate the nexus of Mumbai and its long term resource demand. Our tool is a novel system dynamics model representing the urban water-energy nexus and takes into account characteristics such as intermittent water supply and the presence of slums. We devised scenarios around the Sustainable Development Goals and the Swachh Bharat Mission. The model shows that both can be achieved while saving on future water system infrastructure investments compared to business-as-usual. We find that also in Mumbai end use dominates the nexus. Representing end-use interactions increases expected water demand. This work indicates that globally, sustainable development of infrastructure must consider the urban water-energy nexus.

Journal article

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