The Hamersley Province, located approximately 1200 km north of Perth, Western Australia forms part of the southern Pilbara craton, an extensive area of Band Iron Formations (BIF). The area has a high economic significance due to several enrichment stages of the country rock (BIF) resulting in several large high-grade iron ore deposits. Mount Whaleback near Newman and Mount Tom Price are the largest deposits, where reserves have been estimated at 1400 Mt and 900 Mt respectively. These ore bodies have been quantified as being high grade resources at approximately 64 % iron, with a high lump to fines ratio, and low impurities. The Mount Tom Price ore body is a hematite-rich ore, associated with a variety of shale and some dolomitic units (MacLeod et al., 1963, MacLeod, 1966, Taylor et al., 2001, Morris, 1980). The local hydrogeology of the Mount Tom Price area involves two main aquifer systems. The Dales Gorge member of the Brockman Iron Formation with contributions from the upper mineralised section of Footwall zone make up the main semi confined aquifer within the area. The underlying low permeability Mount McRae Shale and Mount Sylvia Shale lithologies separate a secondary aquifer which is located within the Wittenoom Formation. A dewatering program within Mount Tom Price has been ongoing since installation in 1994. Within the open pit mining industry, pits depths are increasingly being deepened as the easily accessible surface ore has been removed. This involves excavating pit walls below the existing groundwater table, which can lead to instabilities within pit walls. Added to this is the timing and economic considerations which need to be accounted for in a working mine. As dewatering and depressurisation are pivotal to the extraction of ore resources below the groundwater table, there can often be considerable time pressures to maintain planned mine developments (Hall, 2003). The South East Prongs pit, located within the Mount Tom Price mine, holds some of the most valued low impurity, high grade hematite ore. Structurally the South East Prongs is unique as the deposit lies in the base of a steeply dipping double plunging syncline, intersected by the Southern Batter Fault which runs parallel in strike to the Turner Syncline. The current pit floor of South East Prongs is located at 600 mRL. The long term development plan for the western end of this pit includes a further 30 m of excavation to a final depth of 570 mRL. This currently poses a number of stability issues that require resolution before any development can be undertaken. A conceptual understanding of flow dynamics within structurally complex wall rock environment has been generated through the utilisation of finite element numerical modelling. The complex structural setting within the northern wall of the South East Prongs has shown to interact with high conductivity lithologies to promote preferential flow of groundwater from the underling Wittenoom Formation aquifer. Recharge to the semi confined DG aquifer occurs as groundwater travels up shear zones within the South East Prongs Fault Zone before migrating along Brunos Band. An investigation into alternative methods of depressurisation has been recommended to ensure the ongoing management of pore water pressures within the northern pit wall during planned pit cut backs. Limiting recharge from the WF to the pit through stated preferential flow paths has been identified as a potential issue when the remaining DG aquifer is removed. Maintaining the proposed dewatering buffer will be difficult to achieve using the current system. The ability to design optimal pit shells for access and ore recovery as well as an effective dewatering and depressurisation system relies heavily on the a sound geological model. Further to this, time allocations to ensure forward planning deadlines are met can be significantly interrupted if adjustments to initial plans are required.

This thesis has explored the diffusion of tile drainage in Delaware County, Indiana. The study discussed some of the deterrents that hampered agricultural development in the county. These obstacles included the presence of thick forests, vast areas of swampy lands, poor transportation facilities and the absence of local markets. Methods of overcoming some of these problems were then discussed. These included the clearing of forests to prepare land for cultivation, and the use of open ditches and clay tiles to drain the marshes.In addition, the introduction of new drainage techniques such as the laser beam, plow drain, and plastic tile were also discussed. The rate of adoption of plastic tile was then tested statistically to find out if it followed any pattern of distribution. Data obtained through interviews with selected farmers revealed that such an innovation will tend to approximate a growth or "S"-curve in about 1980. The study concluded that the majority of Delaware County farmers are still using clay or concrete tiles.

The two-dimensional problem of tile drainage on sloping heterogeneous lands was considered. The land surface and the impermeable boundaries of the problem were of a general shape. The flow in both the saturated and unsaturated zones was considered and the system was treated as one composite system. The problem was solved by a finite difference numerical method using the successive over-relaxation iterative (SOR) method for the steady state case with no local recharge, and a combined Newton inner iteration and successive over-relaxation outer iteration for the transient state case with local recharge. Both the rising water table and the falling water table cases were simulated. A computer program was written in Fortrain IV language for this purpose, and a UNIVAC 1108 computer system was used. The results of two runs for a hypothetical problem and one run for a field testing problem are presented. The results were compared with some approximate mathematical solutions for the falling water table.

A major challenge facing agriculture is to improve water use and minimize environmental impact while increasing productivity levels. This study, carried out in Winkler, Manitoba, tested four water management treatments: no drainage and no irrigation (NDNI as control), no drainage with overhead irrigation (NDIR), free drainage with overhead irrigation (FDIR), and controlled drainage with subirrigation (CDSI). Each treatment was replicated in three plots during two growing seasons in 2010 and 2011. The monitored variables included soil moisture content, water table depth variation, drainage outflow volume and quality, weather parameters, and agronomic indices. In 2010, yields were 8.48 (NDNI), 10.36 (NDIR), 10.10 (FDIR), and 9.22(CDSI) Mg ha-1 with only the mean yield difference for the NDIR and the CDSI treatments being statistically significant (p = 0.014). In 2011, yields were 9.25 (NDNI), 10.47 (NDIR), 11.28 (FDIR), and 9.49 (CDSI) Mg ha-1 with no statistically significant differences in yield. In 2010, the exports of NO3-N (138 kg ha-1), PO4-P (0.6 kg ha-1) and salts (2.34 Mg ha-1) from the FDIR treatment were significantly larger (p <0.05) than exports from CDSI, which were 0.07 kg ha-1, 0.08 kg ha-1, and 0.41 Mg ha-1, respectively. In 2011, the exports of NO3-N (36 kg ha-1), PO4-P (0.27 kg ha-1), and salts (1.1 Mg ha-1) from FDIR were significantly larger (p < 0.05) than the exports from CDSI which were 10 kg ha-1, 0.08 kg ha-1, and 0.39 Mg ha-1, respectively. These results indicate that irrigation was the main factor driving corn yields under the conditions prevailing in the Canadian Prairies, while subsurface drainage had a beneficial impact when the beginning of the season was wet. Also, this study showed the advantage of controlled drainage over free drainage in reducing the nutrients and salt exports.

ABSTRACT The modern day City of Winnipeg is situated on the poorly drained floor of pro-glacial Lake Agassiz, one of the flattest regions on earth. Within the area now bounded by the Perimeter Highway sixteen major streams and at least twenty small coulees once emptied into the Àssiniboine and Red Rivers. Behind the levees of these rivers large areas of marsh existed providing detention storage of surface waters. The overflow from these wetlands fed many of the streams. The first settlers in the region mimicked the natural drainage regime by damming the waters of the streams to drive grist mills. Later agricultural settlers, occupying the uninhabited but marginally drained lands behind the levees began to drain the wetlands. During the explosive growth period of the City (1880-1910) the drainage regime was radically altered and an expensive and inadequate conduit system was substituted in it's place. Serious flooding episodes have occurred from the first alterations up to the present day. In an attempt to solve the flooding problems, overcome the expense of conduit systems and add amenity, a series of stormwater retention ponds was introduced by private developers in 1965. Functually these impoundments imitate the original hydraulic relationship between the ponds, wetlands and streams of the native landscape. Approximately on hundred years after the elimination of the natural drainage regime, Plan Winnipeg 1981 calls for the preservation of all natural watercourses in recognition of their high value for storm drainage and recreational amenity. Of the original thirty-six streams and coulees only nine exist today. All wetland storage areas have been eliminated. This practicum traces the historical progression of land drainage in the City of Winnipeg, summarizes the design criteria for future urban stormwater management, and outlines the present condition and rehabilitation of the historic water features.

To recover oil remaining in petroleum reservoirs after waterflooding, the gravitationally stable mode of gas injection is recognized as a promising tertiary oil recovery process. Understanding the phenomena occurring over the course of the gravity-assisted inert gas injection (GAIGI) process is thus important. Extensive studies on both secondary and tertiary modes of gravity drainage have shown promising results in recovering oil from homogeneous water-wet glass bead packs, sand packs, and sandstone cores, respectively. However, it is not realistic to anticipate similar flow mechanisms and recovery results in all types of reservoirs because the natural hydrocarbon reservoirs are all heterogeneous in terms of their permeability, porosity, and wettability. Such heterogeneities cause irregular displacement patterns, and nonuniform fluid distribution. The impact of heterogeneity of the porous media on the GAIGI process has not been fully addressed in the experimental studies carried out to date; therefore, this thesis aims to fill in the gap of knowledge on this area. The impact of reservoir wettability and pore structure heterogeneities at the macroscopic scale on the recovery efficiency of the GAIGI process was investigated through a systematic experimental study for tertiary recovery of waterflood residual oil. To obtain heterogeneous (in terms of wettability) packings, isolated inclusions of oil-wet consolidated glass beads were embedded in a continuum of unconsolidated water-wet glass beads. Similarly, the heterogeneous porous media exhibiting permeability heterogeneity consisted of large-pore-size isolated regions randomly distributed in a small-pore-size continuum. Upon waterflooding, significantly higher waterflood residual oil saturation was established in both cases of heterogeneous media in comparison to water-wet homogeneous porous media. The amount of waterflood residual oil varied linearly with the volume fraction of heterogeneities in the packings. Experimental results obtained from tertiary gravity drainage experiments demonstrated that the continuity of water-wet portions of the heterogeneous porous media facilitates the residual oil recovery through the film flow mechanism, provided that the oil spreading coefficient is positive. In addition, owing to the high waterflood residual oil content of the heterogeneous media tested, the oil bank formation occurred earlier and grew faster than that in homogeneous media, resulting in a higher oil recovery factor. However, the favorable wettability conditions in both the homogeneous and heterogeneous porous media exhibiting permeability heterogeneity resulted in slightly lower reduced residual oil saturation after the GAIGI process compared to that in the heterogeneous media with wettability heterogeneity under the same condition of withdrawal rate. In addition, the oil recovery factor at gas breakthrough was found to be inversely related to the production rate due to the functionality of gravity and viscous forces over the course of gravity drainage. These two forces were combined into a dimensionless form, defined as the gravity number (Ngv=Kogg/oVpg). It was discovered that there is a correlation between the oil recovery factor at gas breakthrough and the gravity number for both the heterogeneous and homogeneous media. The correlation of recovery factor at gas breakthrough versus the gravity number in heterogeneous media followed a similar trend as that found for homogeneous water-wet porous media. However, at a given gravity number, the recovery factor in heterogeneous media was greater than that in the homogeneous media. This implies that heterogeneous media will be better target reservoirs for applying the GAIGI process compared to the homogeneous reservoirs.

Siphonic roof drainage systems are finding increasing acceptance amongst architects and builders of large commercial buildings in Australia. The benefits of siphonic roof drainage over conventional roof drainage systems include underground excavation savings, higher flow volumes, fewer outlets and stormwater harvesting and reuse potential. Siphonic roof drainage systems are generally designed using the steady state Bernoulli and the Colebrook-White equations. Both of these equations assume a full bore flow regime which only occurs for short periods in siphonic systems. This means that the majority of storm events do not cause the system to run at its full capacity or efficiency. In Australia, systems are designed to cope with a maximum design rainfall intensity, usually the 1 in 100 year storm event. While the performance of siphonic roof drainage systems at this rainfall intensity is well understood, the system performance at lower rainfall intensities and unsteady flow regimes is largely unknown. This research aims to investigate and identify the improvements which can be effected to the overall performance of siphonic roof drainage by the removal of air from the system. The research will also investigate the effect the air entrainment has on siphonic flows. / PhD Doctorate

Bubbles in water are stabilised against coalescence by the addition of salt. The white froth in seawater but not in freshwater is an example of salt-stabilised bubbles. A range of experiments have been carried out to investigate this simple phenomenon, which is not yet understood.¶ The process of thin film drainage between two colliding bubbles relates to surface science fields including hydrodynamic flow, surface forces, and interfacial rheology. Bubble coalescence inhibition also stands alongside the better known Hofmeister series as an intriguing example of ion specificity: While some electrolytes inhibit coalescence at around 0.1M, others show no effect. The coalescence inhibition of any single electrolyte depends on the combination of cation and anion present, rather than on any single ion.¶ The surfactant-free inhibition of bubble coalescence has been studied in several systems for the first time, including aqueous mixed electrolyte solutions; solutions of biologically relevant non-electrolytes urea and sugars; and electrolyte solutions in nonaqueous solvents methanol, formamide, propylene carbonate and dimethylsulfoxide. Complementary experimental approaches include studies of terminal rise velocities of single bubbles showing that the gas-solution interface is mobile; and measurement of thin film drainage in inhibiting and non-inhibiting electrolyte solution, using the microinterferometric thin film balance technique.¶ The consolidation of these experimental approaches shows that inhibiting electrolytes act on the non-equilibrium dynamic processes of thin film drainage and rupture between bubble surfaces – and not via a change in surface forces, or by ion effects on solvent structure. In addition, inhibition is driven by osmotic effects related to solute concentration gradients, and ion charge is not important.¶ A new model is presented for electrolyte inhibition of bubble coalescence via changes to surface rheology. It is suggested that thin film stabilisation over a lifetime of seconds, is caused by damping of transient deformations of film surfaces on a sub-millisecond timescale. This reduction in surface deformability retards film drainage and delays film rupture. It is proposed that inhibiting electrolyte solutions show a dilational surface viscosity, which in turn is driven by interfacial concentration gradients. Inhibiting electrolytes have two ions that accumulate at the surface or two ions that are surface excluded, while non-inhibiting electrolytes have more evenly distributed interfacial solute. Bubble coalescence is for the first time linked through this ion surface partitioning, to the ion specificity observed at biological interfaces and the wider realm of Hofmeister effects.¶

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains x, 86, [22] p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 58-63).

Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xi, 170 p. : ill. (some col.), maps. Vita. Includes abstract. Includes bibliographical references.