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Theses : Honours

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Articles 1 - 15 of 15

Full-Text Articles in Physical Sciences and Mathematics

Radio Frequency Enabled Soil Redox Potential Sensor Networks, Chris Holme Jan 2006

Radio Frequency Enabled Soil Redox Potential Sensor Networks, Chris Holme

Theses : Honours

There is a need for' cost effective tools and data collection methods for field measurements; to increase both productivity and volumes of collected data in the quest for enhanced understanding and management of environmental systems. To such end, various technologies that may be combined into a cost effective soil redox sensor network were explored. Suitability of each technology, as a component of said network was evaluated. A prototype soil redox sensor network was constructed and basic laboratory and field testing was completed. Results indicate that the prototype sensor network functions correctly within bounds. Both laboratory and field testing show that …


Predicting The Spatial Distribution Of Organic Rich Sediments On The Swan Coastal Plain, Western Australia, David Blake Jan 2005

Predicting The Spatial Distribution Of Organic Rich Sediments On The Swan Coastal Plain, Western Australia, David Blake

Theses : Honours

The Organic Rich Sediments (ORS) of the Swan Coastal Plain (SCP) are an important component of the ecosystem, an important source of habitat and refuge for many species of fauna and act as natural fire control mechanisms through edaphic measures within the landscape. There have been numerous impacts on ORS, with fire now rated as one of the imminent threats to the continued existence and functioning of these entities. Conversely fire is an important tool for land mangers in their efforts to promote biodiversity and manage fuel loads to prevent wildfires, at present many of these ORS are becoming victim …


Improving Nutrient Management At Lake Joondalup, Western Australia, Through Identification Of Key Sources And Current Trajectories, Michelle Cumbers Jan 2004

Improving Nutrient Management At Lake Joondalup, Western Australia, Through Identification Of Key Sources And Current Trajectories, Michelle Cumbers

Theses : Honours

Eutrophication has become a considerable issue for managers of water bodies across Australia. Rapid urbanisation in the south-west of Western Australia is causing the eutrophication of many wetlands within the region. Lake Joondalup is a eutrophic, urban lake, located approximately 20km north of Perth city. It comprises part of the Yellagonga Regional Park, having a high conservation value. The aim of this study was to provide managers of Lake Joondalup with information on the relative importance of different nutrient sources into the lake, thus enabling the development of appropriate management strategies. Additionally, a historical examination of available water quality data …


Multivariate Geostatistical Analysis With Application To A Western Australian Nickel Laterite Deposit, Ellen Bandarian Jan 2003

Multivariate Geostatistical Analysis With Application To A Western Australian Nickel Laterite Deposit, Ellen Bandarian

Theses : Honours

Although it can be time consuming and computationally more expensive to work with multivariate data, it is often desirable to exploit the relationships among and between the variables sampled across a study region. In most cases the availability of this secondary information can enhance the estimation of the primary variable(s). The aim of this research is to describe and then demonstrate the use of multivariate statistical methods in geostatistical analysis. The methods will be illustrated by application to a multivariate data set from an actual mineralisation. The data suite is known as MM22D and comes from the Murrin Murrin nickel …


Direct Sequential Simulation Algorithms In Geostatistics, Robyn Robertson Jan 2002

Direct Sequential Simulation Algorithms In Geostatistics, Robyn Robertson

Theses : Honours

Conditional sequential simulation algorithms have been used in geostatistics for many years but we currently find new developments are being made in this field. This thesis presents two new direct sequential simulation with histogram reproduction algorithms and compares them with the efficient and widely used sequential Gaussian simulation algorithm and the original direct sequential simulation algorithm. We explore the possibility of reproducing both the semivariogram and the histogram without the need for a transformation to normal space, through optimising an objective function and placing linear constraints on the local conditional distributions. Programs from the GSLIB Fortran library are expanded to …


Using Simulated Annealing In Geostatistics, Wesley Wells Jan 2002

Using Simulated Annealing In Geostatistics, Wesley Wells

Theses : Honours

Simulation methods are now used extensively for estimation and prediction in mining and petroleum industries and also in environmental management. In this thesis we describe the method of simulated annealing and examine in detail the GSLIB implementation algorithm SASJM. In the context of two case studies involving both sample and exhaustive data sets, we demonstrate this algorithm and then investigate the effect on the outcome of varying the different algorithm parameters. We also consider the effect of varying the weighting given in the simulated annealing objective function to the reproduction of each of the sample histogram and semivariogram. For the …


Application Of Orthogonal Polynomials To Geostatistics, Ainslie Chapman Jan 2001

Application Of Orthogonal Polynomials To Geostatistics, Ainslie Chapman

Theses : Honours

Geostatistics is a field of study that deals with spatially dependent attributes. As information regarding these attributes is usually only available at sample locations, estimates must be made at unsampled locations. Sample data are usually measured on point support within the study region, however in reality decisions are based on small blocks and not on points. A change-of-support model is required to obtain the theoretical distribution of block values given the sample point values. Estimates arc then made for a collection of blocks, referred to as a panel. Kriging is a generic term adopted by geostatisticians for a family of …


The Assessment Of Satellite Remote Sensing As A Tool For Determining Sea Surface Temperatures In Nearshore Environments, Fabienne Faskel Jan 2001

The Assessment Of Satellite Remote Sensing As A Tool For Determining Sea Surface Temperatures In Nearshore Environments, Fabienne Faskel

Theses : Honours

The use of satellite remote sensing for environmental management applications has seen a marked increase over the past decade. Remotely sensed data are obtainable for a variety of parameters, such as mineral exploration, species migration, and for determining sea surface temperatures (SSTs). This study examined whether satellite remote sensing is a viable option for determining SSTs in coastal waters, as traditionally this application has only been applied to open-ocean, offshore waters. SSTs in the nearshore waters of Rottnest Island, Western Australia, were determined using in situ temperature loggers and remotely sensed satellite data. Initially the accuracy of the satellite sea …


The Use Of Stable Isotopic Signatures Of Marine Biota To Map Sewage Effluent Disposed Into The Marine Environment, Adam Gartner Jan 2000

The Use Of Stable Isotopic Signatures Of Marine Biota To Map Sewage Effluent Disposed Into The Marine Environment, Adam Gartner

Theses : Honours

Recent work indicates that nitrogen stable isotopic signatures of aquatic biota can be used to link nutrient inputs in the marine environment to terrestrial sources. While this technique of tracing nutrients has been shown to be effective in environments that are not nutrient limited, it has not been proved that this method is effective in oligotrophic environments. This study examined whether nitrogen stable isotopic signatures of marine biota can be used to trace the distribution of sewage effluent in highly mixed, nitrogen limited waters, by examining the δ15N values of marine biota situated close to and distant from …


Identification Of Wetland Plant Hydrotypes On The Swan Coastal Plain Western Australia, Robyn Loomes Jan 2000

Identification Of Wetland Plant Hydrotypes On The Swan Coastal Plain Western Australia, Robyn Loomes

Theses : Honours

The hydrology of 19 Swan Coastal Plain wetlands was described in relation to its influence on the composition and stn1cturc of wetland vegetation. Sixty species were identified as ‘wetland’ plants. The water depth ranges, or hydrological envelopes, of these species were determined and species grouped together based on the water regimes they experienced. Descriptions of wetland hydrology suggested that the surface and groundwater levels of the majority of study wetlands had declined in both the short (3-5 years) and long-term (20-50 years). Wetlands belonging to the Bibra Suite did not follow this trend as surface water levels either increased or …


Detecting The Cause Of Acidification At A Seasonal Wetland On The Swan Coastal Plain, Western Australia, Through Laboratory And Field Mesocosm Experiments, Kelli O'Neill Jan 2000

Detecting The Cause Of Acidification At A Seasonal Wetland On The Swan Coastal Plain, Western Australia, Through Laboratory And Field Mesocosm Experiments, Kelli O'Neill

Theses : Honours

Acidification (pH< 4.5) was detected at Lake Jandabup, a shallow, seasonal wetland on the Swan Coastal Plain. Western Australia. Concern has been raised because populations of invertebrate species have declined or disappeared since acidification, potentially compromising the status of the lake as a nature reserve. The Jake bed is underlain with pyrite (feS2), which oxidises when dry producing sulfates, hydrogen ions and ferrous iron. Being seasonal, Lake Jandabup would be expected to be naturally acidic, but the more recent trend has been a prolonged (> 1 year) and extreme acidification (pH < 4.0). This study endeavoured to explain why the Jake may have undergone an acidic change, why it may have recovered and whether it will happen again. It was hypothesised that the acidification may have been caused by prolonged drying of the lake causing excessive oxidation of pyrite which produced more acid than the wetland could neutralise through buffering. The hypothesis was tested through laboratory and field experiments. The laboratory experiment involved taking intact sediment cores from around the lake, drying them for various lengths of time, and measuring pH, sulfate, total iron, total alkalinity and total aridity upon rehydration. Dried sediment from diatomaceous earth under Fe(OH)3 precipitate gave the lowest pH of less than 4.0. High sulfates, low alkalinity and low pH were interrelated. While drying in its own right produced low pH, generally there was no significant difference between drying times for release of selected variables. The field experiment involved the establishment of small in situ mesocosms to test for the effects …


Comparison Of Median Indicator Kriging With Full Indicator Kriging In The Analysis Of Spatial Data, Donna Hill Jan 1998

Comparison Of Median Indicator Kriging With Full Indicator Kriging In The Analysis Of Spatial Data, Donna Hill

Theses : Honours

In the earth sciences, and particularly in the mining of precious metals, data distributions are often strongly positively skewed. When making decisions on the potential profitability of a gold mine, for example, the high values of the distribution are of particular importance. Indicator kriging provides estimates of cumulative distribution functions from which grade tonnage curves may be calculated. Multiple or full indicator kriging requires a semivariogram to be modelled and a kriging system of equations to be solved for each cut off. This can be time consuming and modelling indicator semivariograms at high cut-offs may be difficult because of the …


Temporal And Spatial Patterns In Water Chemistry, Phytoplankton Biomass And Microcrustacea In Lake Joondalup And Beenyup Swamp, Western Australia, Kimberley Upton Jan 1996

Temporal And Spatial Patterns In Water Chemistry, Phytoplankton Biomass And Microcrustacea In Lake Joondalup And Beenyup Swamp, Western Australia, Kimberley Upton

Theses : Honours

Lake Joondalup is one of the largest remaining permanent lakes of the Swan Coastal Plain. Despite increasing urbanisation, it supports highly diverse terrestrial and riparian communities, and an abundant and diverse aquatic fauna. However, like other wetlands of the Swan Coastal Plain, Lake Joondalup is increasingly threatened by eutrophication and degradation. The aims of this study were to describe the patterns in selected physical, chemical parameters, microcrustacean abundance and biomass of Daphnia carinata in Beenyup Swamp and the adjacent sections of Lake Joondalup; to identify the likely factors determining the patterns of phytoplankton biomass in these wetlands; and to suggest …


A Functional Group Approach To Detecting Shifts In Macroalgal Communities Along A Disturbance Gradient, J. C. Phillips Jan 1996

A Functional Group Approach To Detecting Shifts In Macroalgal Communities Along A Disturbance Gradient, J. C. Phillips

Theses : Honours

A recently proposed hypothesis argued that morphologically and functionally similar macroalgae could be grouped to study the structure of macroalgal communities. It was argued that these functional groups can be used to predict changes to community composition that result from disturbance. This study examined whether the functional group model held in detecting changes in macroalgal community structure within one bioregion, by applying it to a habitat exposed to different levels of physical disturbance associated with wave exposure. Results obtained using a functional group approach were compared to those obtained using a species level approach. Three parallel reef lines in Marmion …


Constructed Wetland Design Criteria : A Study Of Their Role In Contaminant Removal From Urban Stormwater Runoff, A. J. Braid Jan 1995

Constructed Wetland Design Criteria : A Study Of Their Role In Contaminant Removal From Urban Stormwater Runoff, A. J. Braid

Theses : Honours

This study was conducted to review effective design criteria for constructed wetlaads treating urban stormwater and to assess the design features of local constructed wetlands in relation to the theoretically ideal design features. The study was generated out of Water Authority of Western Australia (WAWA) concern that existing inconsistent design criteria may result in constructed wetlands not meeting contaminant removal objectives. Three components to the study involved: design criteria compiled from a critical review of relevant literature, field assessment of selected sites with significant differences in design, and a design critique of those sites based on the compiled design criteria. …