Infrastructure Engineering - Theses
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ItemUnderstanding the Co-evolution of Land, Water, and Environmental Governance in Victoria during 1860 - 2016( 2019)There are many cases where the changes in government interventions have resulted in considerable negative consequences to social-ecological systems (SESs) instead of promoting improvement. Difficulties occur in guiding governance change to steer SESs onto desirable pathways. However, the linkage between the degradation of SESs and governance failure remains unclear. To address this gap, this research aims to understand the co-evolution of land, water, and environmental governance through the integration of policy into social-ecological system frameworks (SESFs). This research is presented into three chapters to answer the following three research questions: Research Question 1: How does land, water, and environmental governance steer the SES condition? Research Question 2: How have policy instruments for land, water, and environmental governance developed from 1860 to 2016 in Victoria, Australia? Research Question 3: How have the policy instruments for land, water, and environmental governance co-evolved? Is there any association with biophysical changes? Chapter 3 developed an SES framework by extending the SES frameworks proposed by Ostrom and Anderies. In the proposed framework, SES condition is viewed as the product of the accumulation of policy instruments used in land, water, and environmental governance to rule the interaction between and among components of biophysical and social systems. Policy instruments can help policy analysts explain the linkages between resources, resource users, and public infrastructure providers and which has a significant role in enhancing the robustness of SES. The framework provides a new way to develop a wider recognition and appreciation of dynamic, site-specific biophysical and social system conditions in influencing the government intervention, and in turn, have been shaped by them. In particular, the framework can help policymakers elucidate: 1. how the biophysical system has been understood in SES governance as represented by the relevant policy instruments; 2. how the social system has been set up in SES governance; and 3. how the synergies and trade-offs between the biophysical and social systems have been managed in the governance of the SES. It can help for systematically analyzing SES governance through the configuration of policy instruments. Chapter 4 used the proposed framework to investigate the evolution of policy instruments used in the land, water, and environmental governance in Victoria, Australia. The content analysis of Victorian Acts related to land, water, and environment practices between 1860 to 2016 was conducted. The investigation found that policy instruments to manage the behavior in resource utilization (substantive and procedural policy instruments) did not vary. However, they were differences in the circumstances in which they were implemented, in this case, differing interactions among components of the biophysical and social systems. The policy instruments held a particular focus in managing components of SESs in different periods and the evolution of each policy instrument has its pathway. Four regimes were identified in the evolution of policy instruments used in water governance: reserve, authority, information, and integration regimes. Whilst, policy instruments used in land governance experienced three regimes (authority, information, and integration regimes) and policy instruments used in environmental governance experienced two regimes (information and integration regimes). Chapter 5 associated the co-evolution of land, water, and environmental governance and biophysical changes. The co-evolution was analyzed by unpacking the integration of policy instruments used in land, water, and environmental governance. The integration was analyzed by examining the relationships between SES components covered in policy instruments. Represented by the subtle changes in their integration, the analysis showed the Victorian government’s learning process in adapting and accommodating the natural system and its desire to avoid significant negative impacts on the land, water, and environmental conditions have resulted in the inclusion of the dynamic interaction within SES as the consideration in formulating its policy instruments. Comparing the co-evolution of policy instruments used in land, water, and environmental governance with state-wide changes within the biophysical system, it is found that there is a strong association between the integration of land, water, and environmental governance and the change in SES condition in Victoria from 1860 to 2016. This longitudinal study of Victoria land, water, and environmental governance developed a new way to explain the linkage between natural resources governance and SES condition. Re-constructing government intervention through policy instruments implemented in the land, water, and environmental governance, the study found the way policy instruments were designed and implemented varied with the state of understanding of the dynamic interactions within the SESs. Looking back over Victoria’s history in developing policy instruments used in land, water, and environmental governance, the study suggests that policy instruments should be formulated to address the interactions among components within SES, in this case, policy instruments as managers of interaction within SES. This is crucial to steer SES conditions onto desirable conditions.
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ItemAssimilation of satellite observations into coastal biogeochemical models( 2006-07)This thesis has investigated the improvement of forecasting temperature in a coastal embayment through the assimilation of sea surface temperature (SST) observations. The research was prompted by the increasing pressures on the coastal marine environment. To better manage the environment, an improved understanding of its future state is necessary. Improving the forecasting of temperature advances our knowledge in this direction. Whilst assimilation of SST is routinely carried out for oceans, its use has been minimal in coastal regions, which is more complicated because of anisotropic covariances and a breakdown of geostrophy in the coastal region. Improvements in computing power, and the introduction of ensemble-based assimilation techniques have made the approach followed in this thesis possible. (For complete abstract open document)
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ItemThe digital lodgement of cadastral survey data in Victoria( 1998-12)An integral part of the Victorian land registration system is the lodgement of cadastral data. Originally data was lodged to support the operation of the land market and the legal rights of the individual owner. The purpose for which it was designed, coupled with the technology that was available at the time, resulted in a paper based system of plans and indexes. Due to many external factors, the current land registration system has essentially remained the same for the past 130 years. However the need for cadastral information means that plan lodgement now serves a wider range of needs, and although changes have been made to the system, it would seem that document-based systems are reaching the limit of cost-effective improvement. A detailed study of the Victorian system of data lodgement has shown there to be several inefficiencies within the system, many of which would benefit by the shift to a digital environment. Research has also shown that the Victorian surveying profession is actually quite prepared to adapt to a digital environment, with many surveyors already preparing or submitting plans digitally. Other jurisdictions that are experiencing similar problems to Victoria have progressed substantially in this area and form ideal examples to learn from. The study of these jurisdictions has shown that although technically the process of lodging data in a digital format is quite straightforward, there are still many technical and legal problems that must be resolved. It is envisaged that in the future, data be lodged in a digital format, which would involve there-engineering of the Victorian land registration system as we know it. This thesis explores the concept of the lodgement of cadastral survey data in a digital format, the issues associated with such a change and the long term benefits it will provide to the surveying, mapping and land development industries.
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ItemThe behaviour of salinity and density stratified flows in the Wimmera River, Australia( 1994)A quantitative understanding of the behaviour of salinity and density stratification in the Wimmera River is developed using a combination of field, laboratory and numerical modelling techniques. The Wimmera River, which is located in north-western Victoria, Australia, is a saline stream with a seasonal and highly variable flow regime. Large salt fluxes enter the Wimmera River as a result of surface water inflows from the upper catchment and groundwater inflows in the upper and lower reaches of the stream. During periods of low and zero flow, a series of long deep pools exist along the river, particularly downstream of Horsham. Inflows of saline groundwater accumulate in scour depressions within these large pools and a series of density stratified or saline pools results. Small flows of saline and fresh water down the river can also lead to density stratification. Larger flow events lead to destruction of the density stratification. A model of flow and salinity in a 200 km reach of the Wimmera River is developed using the MIKE 11 model (DHI, 1992a; 1992b). MIKE 11 solves the St Venant equations for gradually varied, unsteady flow and the Advection-Dispersion equation for solute transport. A time-series data base of discharges and salinities for all surface water and groundwater inflows to the river is developed. This was an important step in the model development due to the existence of a significant number of ungauged tributaries and the importance of groundwater as a source of salt. Stream channels are specified in MIKE 11 by defining a channel network and specifying a series of cross-sections along each channel. The channel morphology of the Wimmera River is studied and a methodology for characterising channel variability is developed. It is shown that the Wimmera River channel can be divided into two statistically different channel types which are characterised by a typical length-scale of several kilometres. Using the above analysis as a basis, a stochastic model of stream channel cross-sections is developed for the Wimmera River and used to infill the existing cross-sectional data. The hydraulic implications of along-channel cross-sectional variation are investigated numerically. A one-dimensional model of the Wimmera River is calibrated and tested. This model is applicable to in-bank flows and their associated salinities. The model adequately simulates the routing of water and salt down the Wimmera River. Variations in salinity associated with flow events and the seasonal variation of salinity are reproduced. Field and laboratory investigations of density stratified pools are described. Density stratified pools form as a result of saline groundwater inflows when the stream discharge is less than 200 - 300 Ml/d. The rate at which the stratification develops is quantified for four field sites. Saline water is mixed from density stratified pools during flow events. The mechanism responsible for most of the mixing involves a thin outflow of saline water up the downstream slope of the scour depression. Turbulent entrainment is also responsible for some mixing. During the autumn, convection associated with surface cooling can also mix some density stratified pools. A model of individual density stratified pools, known as Salipool, is developed and tested. Salipool is applied to four density stratified pools in the Wimmera River. A generalised calibration of the mixing relationship incorporated in Salipool is suggested. This generalisation is based on bend sharpness. It is hypothesised that bends have a significant impact on mixing of density stratified pools due to their effect on the vertical velocity profile and the direction of nearbed currents. Salipool is used as a basis for modifying MIKE 11 to incorporate the effect of density stratification.
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ItemModelling hydrologic and climatic controls of closed lakes, western Victoria( 1995)To quantify changes in water level and climate, a water balance model, calibrated using historical climate and lake levels, is used to construct a detailed 16,000 year record of precipitation/evaporation (P/E) ratio for three closed lakes in western Victoria. Lakes Keilambete, Gnotuk and Bullenmerri are maar lakes situated in western Victoria, 200 km W of Melbourne. With high lake/catchment ratios, these lakes are sensitive to atmospheric conditions affecting water balance. Their levels are controlled by direct precipitation and evaporation; groundwater (baseflow) is a minor contributor to the water budget. Previous studies have constructed detailed records of lake levels and palaeosalinities, providing a continuous hydrologic record from 16,000 years ybp to the present. The lakes were observed at high levels by early European settlers but since 1841, waterlevel has undergone the most rapid and sustained decline recorded for the Holocene. Regional meteorological records are used to construct climate series representative of the study area from 1859-1990. Regional homogeneity is demonstrated between the study area and climate stations elsewhere in southern Victoria, South Australia and Tasmania. Climate change recorded at the lakes is therefore indicative of regional climate. No evidence of climate change is found early in the instrumental record, but a statistically significant increase in of 0.3 °C in temperature occurs after 1960. Evaporation is calculated using Morton's Complementary Relationship Lake Evaporation model, utilising long records of air and dewpoint temperature and sunshine ratio. The model calculates water budgets from rainfall, evaporation and baseflow. Baseflow is calculated from the infiltration rate which is derived from modelled soil moisture. Baseflow is optimised for each lake to reproduce the historical fall in lake level. The equilibrium climate for the pre-European lake level is modelled as a P/E ratio of 0.94-0.96, compared to the current ratio of 0.79-0.80. The historical fall in all three lakes preceded the period of instrumental climate measurement and major land-use changes. It is therefore ascribed to a natural climate change. Equilibrium and non-equilibrium modelling of lake water levels have produced detailed estimates of P/E ratios, demonstrating wide climatic fluctuations during the Late Pleistocene and Holocene. Holocene P/E ratios vary from 0.77-0.80 in the early and late Holocene to > 1.10-1.20 from 7,000-5,500 ybp. Late Pleistocene P/E ratio varied between 0.70-0.80. The resultant record enables precise estimates of P and E to be determined if independent estimates of either variable can be supplied. It provides a detailed view of climate throughout the Holocene and is of special relevance to continental and hemispherical climate records. Further information on palaeolake levels from the study lakes and other related maar lakes will permit the construction of an even more detailed record of P/E ratio for the Holocene. With other long records from the region, it will provide a highly detailed record of climate change in south-eastern Australia, dating from the late glacial period. The study lakes also show great potential for monitoring future changes in P/E ratios, particularly precipitation change.
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ItemMeasurement and modelling of irrigation channel seepage in northern Victoria( 1993)The earthen irrigation channel network in northern Victoria is operated and maintained by the Rural Water Corporation of Victoria. Water tables are now within 2 m of the surface throughout a large part of the irrigated area in northern Victoria. Groundwater accessions from seepage losses from earthen irrigation channels contribute to these high water tables and the associated problems of salinisation and water logging. Seepage tests using a pondage method were performed on two irrigation channels near Tatura (36° 26’ S, 145° 16’E) in north-central Victoria. Testing took place over two irrigation seasons (1989-90 and 1990-91) at both channel sites (Tatura East and Dhurringile). Testing also took place during a third irrigation season (1991-92) at the Tatura East site. This study is the most extensive of its kind ever completed within an Australian irrigation system. Seepage rates were calculated for all seepage tests performed (11 at the Tatura East site; 8 at the Dhurringile site). Seepage losses in the upstream pond of the Tatura East channel varied between 20 and 34 mm d-1. In the downstream pond this variation was 14 to 19 mm d-1 under normal pondage conditions. The difference between channel water level and aquifer head was the most significant factor in determining the seepage loss rate from the channel. The related problem of leakage (loss from the channel through holes in the channel bank) was highlighted in this study. Measurements of leakage losses were made in 5 of the 8 tests at the Dhurringile site and estimates of the relative magnitude of seepage and leakage losses were made. The average seepage loss (not including leakage ) during these five tests varied between 5 and 9 mm d-1. The data collected from the Tatura East site included channel water elevation and groundwater elevation in three piezometer transects perpendicular to the channel. Using these data, an existing computer model employing the boundary integral equation numerical method was modified to simulate the seepage processes occurring at this channel site. Physically based algorithms of deep seepage and net evaporation from the water table were added to the model during this study. Through calibration and validation of the model results to the field observations, the aquifer parameters were determined and the processes involved in the transmission of seepage away from the channel were identified.
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ItemState of Victoria: a description of the Loch Garry Flood Protection Scheme: Goulburn River levees( 1924)In dealing with the subject of the Loch Garry Flood Protection Scheme, no attempt will be made to describe in detail all Flood Protective works carried out along the Goulburn River, but, in order to explain clearly the present position in regard to such works, the more important geographical and physical characteristics of the Goulburn River will be described and a brief outline will be given of the steps leading up to the adoption of the present scheme.
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ItemStochastic joint probability modelling of estuarine flood levels( 2004)The determination of the annual exceedence probability (AEP) of extreme water levels, such as the 1% AEP flood level, in complex estuarine systems is an important and yet highly challenging issue. Water level AEP is required for land and water resources planning, emergency management and flood insurance underwriting. Extreme water levels in estuaries are caused by the combined effects of environmental forcings (river floods, winds and coastal ocean levels (COLs)), estuarine hydrodynamics, floodplain topography and catchment conditions. A comprehensive flood study should therefore entail a detailed hydrological, hydraulic and terrain modelling of the entire system. Unfortunately, there is currently no standard procedure for undertaking such a study. The question asked in this thesis is: "Is it possible to estimate, in a scientifically rigorous but computationally efficient way, the AEP of extreme water levels in large and complex estuarine systems such that the spatial and temporal forcing characteristics ranging from catchment to synoptic scales are preserved?" This question is addressed by developing a generic modelling method for application to any estuaries, and testing it on the Gippsland Lakes in southeast Australia - a coastal lagoon system having water surface area of almost 400 km2 and contributing catchment area of over 20,000 km2. The new method is a stratified Monte-Carlo stochastic-deterministic hydro-climatic modelling-based joint probability (MBJP) method. Conceptually, two thousand years of stochastic event-based concurrent hourly forcing sequences (river flows, winds and COLs) that preserve the space-time cross-correlations are generated using a sequence of hydro-climatic models developed in this thesis. Monte-Carlo (MC) simulation of event-based water levels around the estuarine system is then carried out using a calibrated hydrodynamic model (HDM) driven by the generated stochastic forcing sequences. (From Abstract)
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ItemSoil moisture and hydrology of the basalt plains of Western Victoria: a field and computer study of surface hydrology( 1979)This is a field and digital model study of surface hydrology. An attempt is made to relate field measurements to the assumptions of a physically-based deterministic rainfall-runoff model that has been proposed for widespread use in Australia. A major part of the field study was the measurement and interpretation of soil moisture contents obtained with a neutron moisture meter, and two methods were developed and used to provide calibrations appropriate to both locally variable soils and the large (55 km2) study area. Independent estimates of each of the major components of the water balance were made, utilizing data collected on the study by other authorities. Further measurements of field parameters were made to provide independent estimates of the appropriate parameter values for the digital model. A single year of data was used for development of the model and final selection of the parameter values. The prediction of the observed streamflow was used as the basis for this testing, and the hydrological validity of the assumptions upon which the model is based was then tested by a comparison of the internal prediction and the independent measurements of soil moisture contents. The model was found to behave reasonably well, but deficiencies in some of the algorithms were identified. A sensitivity analysis showed that the concept of an infiltration capacity is not important for runoff generation on this catchment, and that the spatial variability of the moisture holding capacity of the soil makes it virtually impossible to estimate this model parameter from field measurements alone. It was found that a simple approximation to this spatial variability provided a more realistic annual hydrograph, and reduced the accuracy required to determine the mean value of this moisture storage capacity from field measurements. The main conclusions are that deterministic models offer a useful approach to the understanding of surface hydrology, although further development is required before the parameter values for such a model can be determined solely from field measurements. The use of the field measurements and the model showed that the hydrology of this catchment is dominated by a nearly impermeable B horizon, that the concept of an infiltration capacity is irrelevant to the generation of storm runoff, and that the spatial variation of the moisture holding capacity of the soil is important. Particular topics for further study include the acceptance of spatial variability in the other algorithms of the model, and the hydrological validation of this and other models on other catchments.
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ItemThe evaluation of surge flow in border irrigation (with special reference to cracking soils)( 1993)Surge flow was identified as a potential method of improving farm water management to both reduce water use and minimise accessions to water table, and therefore to help address the salinity and water-logging problems facing the irrigated areas of the Murray-Darling Basin. Surge flow has been intensively researched in furrow irrigation in the USA, but border strips (which are the dominant application method in south-eastern Australia) and cracking soils have received minimal attention. This study investigated surge response in border irrigation with particular reference to cracking clay soils. Two years' field work resulted in a substantial data set covering four soil types and a range of management options. Surge flow reduces water use on cracking clays by 15-40% compared with continuous irrigation under similar conditions and given the same level of management. A negative response was observed on homogenous fine sandy loams, with up to 30% more water applied in surge flow. The positive response was obtained over a range of cycle ratios from 0.2-0.5 and with off-times from 30-300 minutes. Measured soil moisture distributions in the second season showed that application uniformity was better using long offtimes of around 300 minutes. Calculations of the water balance indicate that a greater proportion of applied water is retained in the root zone in surge flow and accessions are a small proportion of those in conventional irrigation. The strong field response was not supported by infiltration test data which recorded greater water intake in surge flow than in continuous tests. The recirculating infiltrometer over-estimated cumulative infiltration for both surge and continuous application, in both seasons. It was later observed that water advances in subsurface cracks in the off-time, up to 70 m ahead of the surface stream. Additional analysis indicates that the surge response is largely due to a mechanism connected with this phenomenon, which helps reconcile the disagreement between field and infiltration test data. Surges overlapped in every test and this phenomenon cannot be simulated by existing hydraulic models of surge flow and substantial revisions are needed before meaningful calibration can be undertaken. The field work provided a clear statement of the difficulty of obtaining infiltration data on cracking soils, and highlights the need for effective real-time estimation of infiltration parameters to overcome severe temporal and spatial variability in infiltration conditions. An inverse solution of the Zero Inertia model was developed, using a constrained Simplex optimisation algorithm to determine infiltration and roughness parameters from advance and depth profile data plus a compound objective function of the two. Global parameters, with reasonably effective predictive performance, were obtained using a compound objective function with continuous flow data sets and, more tentatively, for surge flow. This work provides practical possibilities for automation of border irrigation, using as little as two sensors to determine one roughness and one infiltration parameter from advance data, providing the Kostiakov exponent can be reliably classified. A minimum offour sensors are needed to identify two Simple Kostiakov infiltration parameters and one roughness value. Longer term, farm-scale trials are now required.