Earlier investigations at South Creek in northeastern Queensland established the importance of overland flow as a hydrologic pathway in this tropical rainforest environment. Since this pathway is ‘fast’, transmitting presumably ‘new’ water, its importance should be reflected in the stormflow chemistry of South Creek: the greater the volumentric contribution to the stormflow hydrograph, the more similarity between the chemical composition of streamwater and of overland flow is to be expected. Water samples were taken during two storm events in an ephemeral gully (gully A), an intermittent gully (gully B) and at the South Creek catchment outlet; additional spot checks were made in several poorly defined rills. The chemical composition of ‘old’ water was determined from 45 baseflow samples collected throughout February. The two events differed considerably in their magnitudes, intensities and antecedent moisture conditions. In both events, the stormflow chemistry in South Creek was characterized by a sharp decrease in Ca, Mg, Na, Si, Cl, EC, ANC, alkalinity and total inorganic carbon. pH remained nearly constant with discharge, whereas K increased sharply, as did sulfate in an ill-defined manner. In event 1, this South Creek stormflow pattern was closely matched by the pattern in gully A, implying a dominant contribution of ‘new’ water. This match was confirmed by the spot samples from rills. Gully B behaved like South Creek itself, but with a dampened ‘new’ water signal, indicating less overland flow generation in its subcatchment. In event 2, which occurred five days later, the initial ‘new’ water signal in gully A was rapidly overwhelmed by a different signal which is attributed to rapid drainage from a perched water table. This study shows that stormflow in this rainforest catchment consists predominantly of ‘new’ water which reaches the stream channel via ‘fast’ pathways. Where the ephemeral gullies delivering overland flow are incised deeply enough to intersect a perched water table, a delayed, ‘old’ water-like signal may be transmitted.

Throughfall measurements were made under primary terra firme rainforest in the Rio Pichis valley, in the Upper Amazon Basin of Peru. Based on 214 precipitation events over nearly 18 months, throughfall was estimated to be 83.1±8.8% of gross precipitation. Regression analysis of all events revealed that gross precipitation is the only significant explanatory variable; the use of one-burst events does not significantly improve the regression relationship. Gross precipitation is, however, a poor predictor of throughfall for small rainfall events. The two forest structure parameters, canopy capacity, S, and free throughfall coefficient, p, were determined to be 1.3±0.2 mm and 0.32±0.18 mm. Rainfall intensity was found to influence these parameters. New methods which attempt to minimize the influence of meteorologic variables are used to estimate the potential values of these canopy parameters.

The topography of first-order catchments in a region of western Amazonia was found to exhibit distinctive, recurrent features: a steep, straight lower side slope, a flat or nearly flat terrace at an intermediate elevation between valley floor and interfluve, and an upper side slope connecting interfluve and intermediate terrace. A detailed survey of soil-saturated hydraulic conductivity (K sat)-depth relationships, involving 740 undisturbed soil cores, was conducted in a 0.75-ha first-order catchment. The sampling approach was stratified with respect to the above slope units. Exploratory data analysis suggested fourth-root transformation of batches from the 0–0.1 m depth interval, log transformation of batches from the subsequent 0.1 m depth increments, and the use of robust estimators of location and scale. The K sat of the steep lower side slope decreased from 46 to 0.1 mm/h over the overall sampling depth of 0.4 m. The corresponding decrease was from 46 to 0.1 mm/h on the intermediate terrace, from 335 to 0.01 mm/h on the upper side slope, and from 550 to 0.015 mm/h on the interfluve. A depthwise comparison of these slope units led to the formulation of several hypotheses concerning the link between K sat and topography.

Orthopyroxenes of a high temperature protomylonite of the Ivrea Zone, Northern Italy show twin like polysynthetic lamellae parallel to {210} of the hypersthene host. The transformation is caused by plastic deformation under high metamorphic conditions which has resulted in dynamic recrystallization of pyroxene and plagioclase. The lamellae consist of clinohypersthene. The twin plane and the lamellar clino-orthoinversion of hypersthene due to natural deformation have not been described hitherto. / Orthopyroxene aus hoch temperierten Protomyloniten der Ivrea-Zone, Nord Italien zeigen polysynthetische Lamellen parallel {210} des Wirtes. Ihr Erscheinungsbild entspricht Deformationszwillingen. Die Lamellen sind invertiert zu Klinohypersthen. Die Ortho-Klino-Transformation ist auf eine Hochtemperaturdeformation zurückzuführen, wie dies anhand der dynamischen Rekristallisation der Pyroxene und Plagioklase bewiesen werden kann. Weder die speziellen Verwachsungsflächen noch die Ortho-Klino-Inversion durch natürliche Deformation wurden bisher beschrieben.

A fine-grained slope that exhibits slow movement rates was investigated to understand how geohydrological processes contribute to a consecutive development of mass movements in the Vorarlberg Alps, Austria. For that purpose intensive hydrometeorological, hydrogeological and geotechnical observations as well as surveying of surface movement rates were conducted during 1998–2001. Subsurface water dynamics at the creeping slope turned out to be dominated by a three-dimensional pressure system. The pressure reaction is triggered by fast infiltration of surface water and subsequent lateral water flow in the south-western part of the hillslope. The related pressure signal was shown to propagate further downhill, causing fast reactions of the piezometric head at 5Ð5 m depth on a daily time scale. The observed pressure reactions might belong to a temporary hillslope water body that extends further downhill. The related buoyancy forces could be one of the driving forces for the mass movement. A physically based hydrological model was adopted to model simultaneously surface and subsurface water dynamics including evapotranspiration and runoff production. It was possible to reproduce surface runoff and observed pressure reactions in principle. However, as soil hydraulic functions were only estimated on pedotransfer functions, a quantitative comparison between observed and simulated subsurface dynamics is not feasible. Nevertheless, the results suggest that it is possible to reconstruct important spatial structures based on sparse observations in the field which allow reasonable simulations with a physically based hydrological model. Copyright  2005 John Wiley & Sons, Ltd. KEY WORDS rainfall-induced landslides; soil creep; hydrological modelling; Vorarlberg; Austria; pressure propagation

Throughout the United States, many areas exceed the level of safe ground ozone (O3) concentration. Non-natural emissions made as result of daily human activities and natural emissions react photochemically to produce ground O3 concentration. Variation in ground O3 concentration is controlled by local and regional emissions, synoptic and mesoscale meteorology, and boundary layer chemistry and dynamics. When the right meteorological variables are present, rural areas can have unhealthy air conditions with high levels of ground O3 concentration similar to that of metropolitan areas. Particular ground O3 concentration episodes were analyzed to summarize what meteorological variables constitute a healthy or hazardous ground O3 day. Hourly ground O3 data for Mammoth Cave National Park from the years, 1998 through 2003 were analyzed. Once analyzed, a combination of meteorological variables is used in a simple linear regression to create the coefficients for empirical predictive model based on 1998-2000 data. The meteorological variables included maximum temperature (Tmax), diurnal temperature range (DTR), solar radiation (SR), and daily precipitation (Pd). The meteorological coefficients were then used with the available meteorological data from 2001 through 2003 to predict ground O3 for 2001 through 2003. Certain meteorological variables such as SR are not easily available in most regions and rural sites in the United States. Therefore, SR was excluded from the regression model to see if rural areas can also forecast ground O3 sufficiently. Root mean square error, d-index, and mean absolute error were used to assess the performance of the predictive model. These measures were calculated to find out if a significant relationship between ground O3 and the meteorological variables is present. For example, the d-index was calculated and ranged from 0.81-0.84 for the best regression model performances. This suggests that the predictive ground O3 from 2001 through 2003 is in agreement with observed ground O3 from 2001 through 2003.

Iron permeable reactive barriers (PRBs) have been installed at sites contaminated with various reducible organic and inorganic chemicals, particularly chlorinated solvents, worldwide. Many geochemical factors can affect the performance of iron PRBs. Chemicals such as nitrate and Cr(VI) may act as competing oxidants when co-exist with chlorinated solvents. Previous studies observed declines in the rate of TCE degradation by granular iron in the presence of nitrate. Passive oxide formation on the iron surface and an increase in corrosion potential of the iron were determined to be the mechanisms for the decline. Cr(VI), being a stronger oxidant than nitrate, may have a similar but greater effect on the iron reactivity. In addition, chromium oxide as well as dissolved CaCO₃, a common groundwater constituent, form secondary precipitates and are likely to further affect the iron reactivity. The primary objective of this study was to determine the effects of Cr(VI) and dissolved CaCO₃ on the iron reactivity towards TCE and Cr(VI) reduction and to provide mechanistic explanations for the observation. In addition, the applicability of a modified reactive transport model (Jeen, 2005) to the system in which chromate and CaCO₃ co-exist with TCE was evaluated. <br /><br /> Column experiments, including measurements of corrosion potential and surface film composition using Raman spectroscopy were conducted. Five column tests were carried out with input solutions consisting of different combinations of TCE (5 mg/L), Cr(VI) (10 mg/L) and dissolved CaCO₃ (300 mg/L) for eight months. <br /><br /> The results from the column receiving only Cr(VI) showed that Cr(VI) was reduced rapidly by the granular iron and was not detected beyond 10 cm from the influent end of the column by the end of the experiment. However, Cr(VI) profiles migrated from the influent end further into the column overtime, suggesting progressive passivation of the iron near the influent end of the column. The gradual increase in corrosion potential (up to 180 mV positive shift) at the port 3 cm from the inlet with the migration of Cr(VI) profiles suggests the formation and accumulation of higher valent iron oxides, such as hematite and goethite, together with Cr(III) products on the iron surface, passivating iron material. Raman spectroscopic measurements confirmed the presence of passive iron oxides at the end of the experiment. For the column receiving Cr(VI) + TCE, the co-existence of TCE did not affect Cr(VI) reduction kinetics. However, the presence of Cr(VI) affected TCE degradation significantly. Two segments in the migration of TCE profiles are identified: the first segment near the influent end of the column, where the iron was still active towards Cr(VI) reduction but inactive towards TCE degradation, and the second segment where Cr(VI) was fully removed and the TCE degradation continued to follow pseudo-first-order kinetics. The migrations in Cr(VI) and TCE profiles suggest that iron was passivated by Fe(III)/Cr(III) products, and Cr(VI), being a stronger oxidant, was reduced much more rapidly than TCE. It is expected that the first segment of TCE profiles would extend gradually with the migration of Cr(VI) profiles over time. <br /><br /> When dissolved CaCO₃ was added to the columns with Cr(VI) and TCE, either as single contaminant, or as co-contaminants, the pH values near the influent end of the columns remained relatively low (~ pH 7), thus, the presence of dissolved CaCO₃ resulted in a stable corrosion potential and faster degradation rates of TCE and Cr(VI). Over time, however, Cr(VI) reduction and iron corrosion produced OH- and shifted the carbonate-bicarbonate equilibrium, resulting in the precipitation of secondary carbonate minerals, as detected by Raman analysis in the three columns containing CaCO₃. The precipitation and accumulation of the secondary minerals on the iron surface gradually decreased iron reactivity, as indicated from the progressive migrations of TCE profiles in the column receiving TCE +CaCO₃ and of second segment TCE of profiles in the column receiving TCE + Cr(VI) + CaCO₃. Over the experimental period, the enhancement of dissolved CaCO₃ was much greater than the iron passivation by secondary mineral precipitates. <br /><br /> Based on the laboratory experiments, Jeen (2005) developed an empirical formula relating the decrease in iron reactivity to the accumulation of secondary minerals, and incorporated this formula into kinetic expression of an existing multi-component reactive transport model (MIN3P). The same code was used in this study to simulate the experimental data. The model reproduced the observations from the columns in which TCE co-exists with Cr(VI) and CaCO₃ quite well, which suggests this model has applicability to predict the long-term performance of an iron PRB when treating groundwater containing Cr(VI), TCE and CaCO3, though there are some potential areas for improvements, including inconsistent volume fractions of secondary carbonate minerals and Fe(III)/Cr(III) products between experimental measurements and model simulation results, the reactive surface area concept, and inability to adapt changes in iron corrosion rates. <br /><br /> The long-term performance for a hypothetical scenario in using an iron PRB (40 cm thick) to treat groundwater where TCE (5 mg/L) co-exists with Cr(VI) (10 mg/L ) in the presence of CaCO3 (300 mg/L) was simulated. The simulation indicated that Cr(VI) was completely treated over a period of 30 years, however, TCE broke through before 20 years, and substantial porosity was lost due to the accumulation of carbonate precipitates. The prediction could be valuable in the design of PRBs or in the development of effective maintenance procedures for PRBs treating groundwater co-contaminated with chromate and TCE.

A Deep Geologic Repository (DGR) for Low and Intermediate Level (L&IL) Radioactive Waste has been proposed by Ontario Power Generation for the Bruce Nuclear site in Ontario Canada. The DGR is to be constructed at a depth of about 660 m below ground surface within the argillaceous Ordovician limestone of the Cobourg Formation. The objective of this thesis is to develop a regional-scale geologic conceptual model for the DGR site and to describe modelling using FRAC3DVS-OPG that provides a basis for the assembly and integration of site-specific geoscientific data. The numerical model is used to explain and illustrate the influence of conceptual model, parameter and scenario uncertainty on predicted long-term geosphere barrier performance. The modelling also provides a framework for hydrogeologic and geochemical investigations of the DGR, serves as a basis for exploring potential anthropogenic and natural perturbations to the DGR system, and demonstrates the long-term stability of the deep system. In the geologic framework of the Province of Ontario, the Bruce DGR is located west of the Algonquin Arch within the Bruce Mega-Block at the eastern edge of the Michigan Basin. Well logs have been used to define the structural contours at the regional and site scale of the up to 37 units that may be present above the Precambrian crystalline basement rock. The regional scale domain is restricted to a region extending from Lake Huron to Georgian Bay. While the selection of a larger domain might decrease the contribution of boundary condition uncertainty to any uncertainty in any site-scale performance measure, it significantly increases the contribution of the uncertainty in the spatial characterization to the uncertainty of the selected measure. From a hydrogeologic perspective, the domain can be subdivided into three horizons: a shallow zone characterized by the units of the Devonian; an intermediate zone comprised of the low permeability units of the Silurian and the shale units of the upper Ordovician; and a deep groundwater domain or zone characterized by units, such as the Cobourg formation, with stagnant water having high total dissolved solids concentrations that can exceed 200g/l. Hence, the conceptual model of the Bruce DGR site required the development of constitutive models that relate the fluid density and viscosity to the fluid total dissolved solids (TDS), temperature and pressure. The regional-scale hydrogeologic modelling will help demonstrate that at the proposed repository horizons, there are low energy gradients and that the combination of the low permeabilities and gradients will result in diffusional groundwater systems with favourable retardation properties.

Two municipal landfills and one public septic system in Southern Ontario were studied as potential sources of the pharmaceuticals ibuprofen, carbamazepine, gemfibrozil, caffeine, sulfamethoxazole, and naproxen to groundwater. The background chemistry at each site was also determined. Pharmaceutical analysis was conducted using isotope dilution techniques, coupled with solid phase extraction followed by high performance liquid chromatography electrospray tandem mass spectrometry (HPLC-ESI- MS/MS). An assessment of method performance and extensive quality assurance and quality control practices were employed. At the septic system site, pharmaceuticals were detected at the furthest sampling point, 30 m downgradient from the source area. The highest concentrations measured in groundwater were for carbamazepine (2,050 ng L-1), sulfamethoxazole (1,990 ng L-1) and ibuprofen (1,790 ng L-1). The other pharmaceuticals analysed were observed at concentrations in the range of <1 to 10 ng L-1 (gemfibrozil), <8 to 625 ng L-1 (naproxen), and <1 to 160 ng L-1 (caffeine). Under saturated groundwater transport, attenuation was not strong within the plume as all pharmaceuticals were detected at distance from the source. In the unsaturated zone, most pharmaceuticals appeared to be more greatly attenuated than in the saturated zone. This greater extent of removal in the unsaturated zone is attributed to increased degradation associated with elevated oxygen concentrations. At the two landfill sites, no pharmaceutical compounds were detected in any of the groundwater samples collected within previously defined plumes. Assuming these drugs are disposed in landfill wastes, the absence of detections suggests degradation and attenuation of these pharmaceuticals is occurring. Some of the conditions that may contribute to attenuation include a thick unsaturated zone, strongly reducing conditions, and high sorptive capacity of the waste. Specifically, waste typically has a higher organic content than aquifer materials, and a lower pH, particularly in the early stages of decomposition. These conditions would result in a potentially higher attenuation of drugs within the waste pile. This study suggests that management programs focused on protection of groundwater quality should take into consideration the potential persistence of pharmaceuticals in septic system environments.

Packer tests in boreholes in fractured rock involving injection or withdrawal of water in borehole segments have been standard practice in bedrock hydraulic investigations pertaining to geotechnical and water resource projects since the 1950’s. However in contaminant hydrogeology, the tests are conducted to assess groundwater velocity and contaminant fluxes and therefore, much improved resolution and measurement accuracy is needed. For this thesis study packer testing equipment was designed specifically for studies of contaminant behavior in fractured rock with the ability to conduct four types of hydraulic tests: constant head/flow injection step tests, slug tests, pumping tests and recovery tests, all in the same borehole test interval without removing the equipment from the hole while acquiring high precision data for calculation of transmissivity (T) and fracture hydraulic apertures (2b). This equipment records pressure above, within, and below the test interval to gain insights regarding open borehole flow patterns, and to identify short circuiting to the open borehole above or below the test interval. The equipment measures flow rates as low as 6 ml/min up to 20 L/min, and the temperature in the test interval and at the ground surface is measured to account for density and viscosity variations. Each type of test is conducted repeatedly over a wide range of imposed applied pressures and flow rates and the equipment was applied to assess performance of this new methodology for packer testing and gain new insights concerning fractured rock hydrology in 6 boreholes in the fractured dolostone aquifer underlying the City of Guelph, Ontario. In the first stage of the equipment application in the fractured dolostone aquifer, over 150 high precision straddle packer tests using constant rate injection (Q) were conducted to identify the conditions of change from Darcian (linear) to non-Darcian (non-linear) flow based on the Q vs dP relationship where dP is the applied pressure above ambient. In the Darcian regime, the linear Q vs dP relationship passes through the origin (0,0) where the ambient pressure represents static conditions (i.e. Q=0 and dP=0). After the onset of non-Darcian flow, proportionally less Q per unit dP occurs so that the interval transmissivity (T) calculated from the test results using Darcy’s Law based models is underestimated by as much as an order of magnitude. The Darcy-Missbach equation was found to be a robust conceptual model for representation of step constant Q tests in which the linear proportionality constant relates Qn vs dP. It was found that quantifying non-linear flow allows for a more accurate determination of the linear data to obtain better estimates of T and hence the hydraulic apertures derived from the T using the Cubic Law. In order to obtain hydraulic apertures from the packer test T values, the number of hydraulically active fractures in the test interval is needed. The only data collected regarding individual fractures was the core log created during the coring process and the acoustic televiewer log, both of which identify the location of fractures, but neither could tell if the fractures identified were hydraulically active. A sensitivity analysis concerning the effects of non-linear flow and the number of hydraulically active fractures on the calculated hydraulic aperture shows that the number of fractures selected as hydraulically active has the greatest effect on the aperture values. A new approach is proposed for determining apertures from hydraulic tests in fractured rock utilizing the onset of non-linear flow to aid in the choice of the number of active fractures present in the test interval. In the second stage of the equipment application, the four types of hydraulic tests (constant head, pumping, recovery, and rising/falling head slug tests) conducted in the same test interval at gradually increasing flow rates showed that non-linear flow can be most easily identified and quantified using constant head tests providing a higher degree of certainty that the data used to calculate T are from the Darcian flow regime. Slug tests are conducted most rapidly, but formation non-linear behavior is commonly exaggerated by non-linearity within the test equipment at large initial displacements. However, the equipment non-linearity can be accounted for using a Reynolds number (Re) analysis allowing identification of the non-linear flow in the formation. In addition, non-linear flow can interfere with evidence of fracture dilation. The pumping and recovery tests are the most time consuming because of the relatively long time required to reach steady state. However, these tests offer the most potential to give insight into the influences of the peripheral fracture network and rock matrix permeability on test results In addition to the actual transmissivity of the test interval T values obtained from packer tests can be influenced by several factors including non-linear flow in the formation and in the test equipment, aperture dilation or closure, hydraulic short circuiting or leakage from the test interval to the open borehole and dual permeability properties of the system (fractures and matrix). The equipment and procedures developed in this thesis provide an improved framework for identifying these influences and in some cases avoiding them so that the aperture values calculated from T measurements are more accurate than those obtained through conventional approaches. In the conventional procedures for packer testing in fractured rock as recommended in manuals and guidance documents, the applied head and flow rate can be expected, based on the results of this thesis, to produce transmissivity values biased low because of non-linear (non-Darcian) flow.