Infrastructure Engineering - Research Publications
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ItemNo Preview AvailableThe Music of Rivers: The Mathematics of Waves Reveals Global Structure and Drivers of Streamflow Regime(AMER GEOPHYSICAL UNION, 2023-07)Abstract River flows change on timescales ranging from minutes to millennia. These vibrations in flow are tuned by diverse factors globally, for example, by dams suppressing multi‐day variability or vegetation attenuating flood peaks in some ecosystems. The relative importance of the physical, biological, and human factors influencing flow is an active area of research, as is the related question of finding a common language for describing overall flow regime. Here, we addressed both topics using a daily river discharge data set for over 3,000 stations across the globe from 1988 to 2016. We first studied similarities between common flow regime quantification methods, including traditional flow metrics, wavelets, and Fourier analysis. Across all these methods, the flow data showed low‐dimensional structure (i.e., simple and consistent patterns), suggesting that fundamental mechanisms are constraining flow regime. One such pattern was that day‐to‐day variability was negatively correlated with year‐to‐year variability. Additionally, the low‐dimensional structure in river flow data correlated closely with only a small number of catchment characteristics, including catchment area, precipitation, and temperature—but notably not biome, dam surface area, or number of dams. We discuss these findings in a framework intended to be accessible to the many communities engaged in river research and management, while stressing the importance of letting structure in data guide both mechanistic inference and interdisciplinary discussion.
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ItemNo Preview AvailableDepth camera-based model for studying the effects of muscle loading on distal radius fracture healing(PERGAMON-ELSEVIER SCIENCE LTD, 2023-09)BACKGROUND: Distal radius fractures (DRFs) treated with volar locking plates (VLPs) allows early rehabilitation exercises favourable to fracture recovery. However, the role of rehabilitation exercises induced muscle forces on the biomechanical microenvironment at the fracture site remains to be fully explored. The purpose of this study is to investigate the effects of muscle forces on DRF healing by developing a depth camera-based fracture healing model. METHOD: First, the rehabilitation-related hand motions were captured by a depth camera system. A macro-musculoskeletal model is then developed to analyse the data captured by the system for estimating hand muscle and joint reaction forces which are used as inputs for our previously developed DRF model to predict the tissue differentiation patterns at the fracture site. Finally, the effect of different wrist motions (e.g., from 60° of extension to 60° of flexion) on the DRF healing outcomes will be studied. RESULTS: Muscle and joint reaction forces in hands which are highly dependent on hand motions could significantly affect DRF healing through imposed compressive and bending forces at the fracture site. There is an optimal range of wrist motion (i.e., between 40° of extension and 40° of flexion) which could promote mechanical stimuli governed healing while mitigating the risk of bony non-union due to excessive movement at the fracture site. CONCLUSION: The developed depth camera-based fracture healing model can accurately predict the influence of muscle loading induced by rehabilitation exercises in distal radius fracture healing outcomes. The outcomes from this study could potentially assist osteopathic surgeons in designing effective post-operative rehabilitation strategies for DRF patients.
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ItemChanges in joint lubrication with the degree of meniscectomy and osteochondral junction integrity(Elsevier BV, 2023-11)This study focuses on the relationship between meniscectomy and osteochondral junction health, and their integrity on cartilage lubrication. Using a previously published multi-component joint computational model, we explored the impact of increasing degree of meniscectomy and osteochondral flow conductivity on joint lubrication. Results suggest a greater effect of meniscectomy on joint lubrication when the osteochondral junction is healthy. However, the impact is less pronounced when the osteochondral junction is already diseased due to compromised lubrication capability. This research provides a first-time quantitative analysis of this interaction, which highlights the importance of adequately evaluating the osteochondral junction’s condition before meniscectomy surgery. It also suggests that reducing post-surgery activity level may be beneficial for patients with diseased junctions undergoing meniscectomy.
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ItemUsing Ensemble Streamflow Forecasts to Inform Seasonal Outlooks for Water Allocations in the Murray Darling Basin(ASCE-AMER SOC CIVIL ENGINEERS, 2023-09-01)Water is a limited and highly valuable resource. In many parts of the world, water agencies allocate water according to agreed entitlement systems. The allocations are largely based on water already available in storages and rivers. Water agencies may also issue seasonal water allocation outlooks by anticipating future inflows to the storages and rivers. These outlooks are meant to assist water entitlement holders to plan for their crop planting, irrigation, and participation in water markets. Currently, these outlooks are generally based on historical inflow observations (climatology) and are often determined for a small selection of possible climatic scenarios (e.g., extreme dry, dry, average, and wet). These outlooks have large uncertainties, which require users to manage high risks themselves, leading to inefficient water use. In this study, we investigate the use of ensemble seasonal inflow forecasts to improve the production of seasonal water allocation outlooks through a case study of the Goulburn system in central Victoria, Australia. This is a complex system with active water trade both within the region and outside with the larger connected southern Murray-Darling Basin. In this case study, we integrate Australian Bureau of Meteorology's seasonal streamflow forecasts with Goulburn-Murray Water's water allocation to produce fully probabilistic water allocation outlooks. We evaluate the outlooks for three irrigation seasons from 2017 to 2020. We compare these outlooks with those produced from using inflows based on climatology only, an approach akin to the current practice of Goulburn-Murray Water. Using seasonal streamflow forecasts resulted in outlooks up to 60% (average 20%) closer to actual determinations, with uncertainty reduced by up to 65% (average 19%) Improvements were most obvious for short lead times and later in the irrigation season. This is a clear demonstration of how integration of streamflow forecasts can improve end-user products, which can lead to more efficient water use and water market participation.
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ItemChanges in flood-associated rainfall losses under climate change(ELSEVIER, 2023-10)Climate change is expected to impact the severity and frequency of floods, which has implications for flood risk management. Design floods and derived flood frequency curves obtained using event-based rainfall-runoff models are widely used in industry to assess flood risks for planning and design purposes. For these approaches it is necessary to have (a) rainfall inputs, and (b) rainfall losses specified, the latter representing the amount of rainfall that is either intercepted, stored on the surface, or infiltrated into the soil and does not contribute to the flood hydrograph. There is extensive research on changes in flooding under climate change that focus on projections of rainfall. However, there is little research into projections of rainfall losses under climate change, despite the knowledge that their changes will modulate the flood response. Here, we present one of the first studies seeking to quantify how rainfall losses, as represented by estimates of initial and continuing losses used in event-based models, are projected to change under climate change. We identify dependencies between rainfall losses and antecedent soil moisture in around half (over 200) of the largely unregulated catchments (i.e. watersheds) in Australia analysed in this study and use these relationships to project rainfall losses under climate change. Near universal increases in both the mean and variance of both initial losses and continuing losses are projected in these catchments, suggesting that increased rainfall losses could offset the impact of increased rainfalls for frequently occurring floods and result in an increased variance in flood responses.
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ItemHigh water use plants influence green roof substrate temperatures and their insulative benefits(Elsevier BV, 2023-12-01)Green roofs are amongst the solutions employed to deliver sustainable buildings in cities. Their vegetation and substrate layers can reduce the heat transfer through the roof, thus potentially reducing energy used for building cooling and heating. However, little research has investigated the insulative properties of drought-tolerant plants which also have high water use. These plants have been found to improve runoff retention by removing larger volumes of water from the substrate through higher transpiration rates than succulents. This planting strategy may also enhance green roof cooling performance due to their greater evapotranspiration rates. In this study, the thermal performance of three drought-tolerant species with high water use — Lomandra longifolia, Dianella admixta, and Stypandra glauca — was evaluated and compared with a commonly used succulent species (Sedum pachyphyllum) and a bare unplanted module. L. longifolia had the best insulative performance during the entire investigated period, reducing green roof substrate surface temperature up to 1.86 °C compared to succulent S. pachyphyllum. In summer, the mixture reduced heat gain to a greater extent than monoculture plantings of all species except L. longifolia. Summer measurements also suggest that plants with high leaf area index (LAI) and higher albedo should be selected to reduce surface temperatures. High evapotranspiration rates of high water use L. longifolia led to greatest reduction of bottom surface temperatures during a heatwave when decreasing its water content from 18.5% to 2.9%. Results obtained using an analytical hierarchical partitioning technique indicated air temperature had the most significant impact on temperatures at both the surface of the planting substrate and the bottom of each green roof unit, accounting for 48% to 58% of the variation.
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ItemNo Preview AvailableManaging underground legal boundaries in 3D - Extending the CityGML standard(Elsevier BV, 2023-08)Legal boundaries are used for delineating the spatial extent of ownership property’s spaces. In underground environments, these boundaries are defined by referencing physical objects, surveying measurements, or projections. However, there is a gap in connecting and managing these boundaries and underground legal spaces, due to a lack of data model. A 3D data model supporting underground land administration (ULA) should define and model these boundaries and the relationships between them and underground ownership spaces. Prominent 3D data models can be enriched to model underground legal boundaries. This research aims to propose a new taxonomy of underground legal boundaries and model them by extending CityGML, which is a widely used 3D data model in the geospatial science domain. We developed, implemented, and tested the model for different types of underground legal boundaries. The implemented prototype showcased the potential benefits of CityGML for managing underground legal boundaries in 3D. The proposed 3D underground model can be used to address current challenges associated with communicating and managing legal boundaries in underground environments. While this data model was specifically developed for Victoria, Australia, the proposed model and approach can be used and replicated in other jurisdictions by adjusting the data requirements for underground legal boundaries.
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ItemLand use and land cover (LULC) performance modeling using machine learning algorithms: a case study of the city of Melbourne, Australia.(Nature Portfolio, 2023-08-19)Accurate spatial information on Land use and land cover (LULC) plays a crucial role in city planning. A widely used method of obtaining accurate LULC maps is a classification of the categories, which is one of the challenging problems. Attempts have been made considering spectral (Sp), statistical (St), and index-based (Ind) features in developing LULC maps for city planning. However, no work has been reported to automate LULC performance modeling for their robustness with machine learning (ML) algorithms. In this paper, we design seven schemes and automate the LULC performance modeling with six ML algorithms-Random Forest, Support Vector Machine with Linear kernel, Support Vector Machine with Radial basis function kernel, Artificial Neural Network, Naïve Bayes, and Generalised Linear Model for the city of Melbourne, Australia on Sentinel-2A images. Experimental results show that the Random Forest outperforms remaining ML algorithms in the classification accuracy (0.99) on all schemes. The robustness and statistical analysis of the ML algorithms (for example, Random Forest imparts over 0.99 F1-score for all five categories and p value [Formula: see text] 0.05 from Wilcoxon ranked test over accuracy measures) against varying training splits demonstrate the effectiveness of the proposed schemes. Thus, providing a robust measure of LULC maps in city planning.
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ItemModelling underground cadastral survey data in CityGML(Wiley, 2023)In underground environments, survey elements such as survey points and observations provide the information required to define legal boundaries. These elements are also used to connect underground legal spaces to a geodetic survey network. Due to the issues of current 2D approaches for managing underground cadastral data, prominent 3D data models have been extended to support underground land administration. However, previous studies mostly focused on defining underground legal spaces and boundaries, with less emphasis on survey elements. This research aims to extend CityGML to support underground cadastral survey data. The proposed extension is based on the survey elements elicited from underground cadastral plans, which is then implemented for an underground case study area in Melbourne, Australia. This extension integrates underground survey data with legal and physical data in a 3D digital environment and provides an improved representation of survey elements, facilitating the management and communication of underground cadastral survey data.
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ItemWhole-life baseline carbon assessment of residential building stock – A Victorian case study(Australian Life Cycle Assessment Society (ALCAS), 2023-07-19)Assessing residential building decarbonisation opportunities requires a whole-life approach, given the increasing share of embodied carbon as housing becomes more energy efficient. Since most of the projected housing stock would consist of existing buildings, emissions from renovation should also be included in determining both embodied and operational carbon in the residential building sector. A bottom-up typology framework was developed to estimate carbon emissions for existing and new housing up to 2050, scalable from local government area (LGA) to state-level jurisdiction which allows for granularity in testing scenarios for the future. Housing typologies were developed for existing, new, and renovation housing stock based on census data. Operating carbon was obtained using building energy simulation while embodied carbon data was accounted from localised life cycle construction datasets. The state of Victoria along with its corresponding LGAs was used as a case study for said framework. Heating load comprised most of the operating energy demand for most typologies while external walls and floors contributed significant embodied carbon for new residential buildings, particularly for detached houses. For Victoria, detached houses built prior to 1991 contributed most of the operational carbon, however with high construction rates set for most LGAs, new housing may contribute more GHG emissions in 2050. Brick veneer housing yielded more embodied carbon from the external wall compared to timber homes while concrete slabs used in floors also incurred a large amount of embodied carbon for the residential building stock. Renovating existing housing has the potential to reduce operating energy demand while emitting less embodied carbon, thus policies on this should be considered in developing decarbonisation pathways. Using the bottom-up typology whole-life carbon framework offers granularity in analysing individual-level carbon impact which can be expanded to LGA and state level.