Groundwater is an important resource that is relied on by approximately half of the world’s population for drinking water supply. Source water protection efforts rely on an understanding of flow and contaminant transport processes in aquifers. Bedrock aquifers are considered to be particularly vulnerable to contamination if the overburden cover is thin or inadequate. The objective of this study is to further the understanding of modeling, sampling, and the potential for anthropogenic contamination in fractured bedrock aquifers. Two numerical modeling studies were conducted to examine geochemical groundwater sampling using multi-level piezometers and the role of discretization in a discrete fracture radial transport scenario. Additionally, two field investigations were performed to study the variability of bacterial counts in pumped groundwater samples and the potential for anthropogenic contamination in a bedrock aquifer having variable overburden cover in a semi-urban setting. Results from the numerical modeling showed that choosing sand pack and screen materials similar in hydraulic conductivity to each other and the fractures intersecting the borehole can significantly reduce the required purge volume. Spatiotemporal discretization was found to be a crucial component of the numerical modeling of solute transport and verification of the solution domain using an analytical or semi-analytical solution is needed. Results from the field investigations showed fecal indicator bacterial concentrations typically decrease on the order of one to two orders of magnitude from the onset of pumping. A multi-sample approach that includes collection at early-time during the purging is recommended when sampling fecal indicator bacteria for the purpose of assessing drinking water quality. Surface contaminants in areas with thin or inadequate overburden cover can migrate quickly and deeply into the bedrock aquifer via complex fracture networks that act as preferential pathways. While the presence of fecal indicator bacteria in groundwater samples signifies a possible health risk through human consumption, it was the suite of pharmaceuticals and personal care products that allowed the identification of septic systems and agriculture as the dominant sources of contamination. Land-use planning and source water protection initiatives need to recognize the sensitivity of fractured bedrock aquifers to contamination. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2011-02-28 17:27:54.806

Detta projekt handlar om att skapa en ny hemsida till Åhus Beach. Huvudmålen är att den ska vara fullt responsiv och fullt ut dynamisk. För att göra hemsidan dynamisk har vi använt oss av wordpress som CMS-verktyg. För att kunna utnyttja wordpress till dess fulla potential har vi använt oss av ett plugin som heter Advanced Custom Fields Pro. Nästan allting på hemsidan så som texter, bilder, färger, knappar och även sidor är möjliga att ändra på via wordpress. Miljön som använts är en wordpress boilerplate som kallas Bedrock tillsammans med ett starttema som kallas Sage och allting har kodats i Visual Studio Code. Med allt detta tillsammans har vi utvecklat en fullständig ny och fräsch hemsida till Åhus Beach. Slutresultatet är en sida som innehåller sidor för tre olika evenemang, deras undersidor med menyer. Sidan innehåller nyheter, erbjudanden, information om eventen, kartor, kontaktinformation, sökfunktion och videos.

A well, situated on Listerlandet in the western part of Blekinge in Sweden, has a very high content of nitrate. Water with a too high content of nitrate is hazardous to human health, in particular to small children. The area surrounding the well is mostly drained agricultural land with some larger farms for chicken and mink. The well takes its water from the bedrock and is deeper than most other wells affected by nitrate. The bedrock in the area is dominated by limestone with a relatively high flow of water. This thesis was performed in order to find the source of the nitrate. A groundwater model, simulating the water flow, was created. The model was used to trace the particles flowing to the well in order to find the most likely source. GMS Modflow and Modpath were used to create the model. The validation of the model shows that the model is good enough to be used for further investigation of the groundwater in the area. The model result indicates that the original source for most of the nitrate is some large mink farms situated on the slope of a hill south of the well. Calculation shows that it takes the water 25 years to flow from the farms to the well. There is also a probable contribution of nitrate from the agriculture in the vicinity of the well. But an extensive drainage system brings most of the water from the cultivated area into the Baltic Sea. Conclusions are that a large amount of mink farms placed in a small area contributes to the high content of nitrate in the well. Further examinations are needed to show which measures should be taken in order to diminish the content of nitrate in the well. / En brunn som förser Hörvik med dricksvatten har en hög halt av nitrat. Hörvik ligger på Listerlandet i västra Blekinge. Vatten med för hög nitrathalt är hälsovådligt för människor i allmänhet och spädbarn i synnerhet. Området som omger brunnen består till största delen av dränerad jordbruksmark med några större djurgårdar för broiler och mink. Brunnen är bergborrad och går djupare än de flesta andra nitratpåverkade brunnar i Sverige. Berggrunden i området domineras av kalkberg med ett relativt högt vattenflöde. Ett projektarbete utfördes för att ta reda på ursprungskällan till nitratet. I arbetet skapades en grundvattenmodell som skulle simulera vattenflödena i området och sedan spåra en partikels väg till brunnen för att ta reda på den mest troliga källan. GMS Modflow och Modpath är de dataverktyg som användes. Valideringen av modellen visar att den fungerar tillfredsställande och kan användas för fortsatta undersökningar av grundvattenförhållanden i området. Modellresultat tyder på att ursprungskällan för den största delen av nitratet är några stora minkfarmar som ligger på en sluttning upp mot Listers huvud söder om brunnen; dock har det tagit ca 25 år för vattnet att ta sig från ursprungskällan till brunnen. Jordbruket i närheten av brunnen bidrar sannolikt med en del nitrat, men en omfattande dränering leder den större delen av vattnet från jordbruksområdet ut i Östersjön. Slutsatsen är att ett stort antal minkfarmar i ett begränsat område är en bidragande orsak till brunnens höga nitrathalt. Vidare undersökningar bör visa vilka åtgärder som behövs för att minska nitrathalten i brunnen.

Mafic bedrock being beneficial to vegetation is a relationship that is being mentioned in different kinds of nature related litterature. This relationship is however not always explained and other factors may be as important as, or even more influential than, the bedrock content. In this study the relationship between mafic rock and protected areas of nature is being examined, based on the following questions. -          How does geology, with respect to bedrock content and weathering, create benign conditions for vegetation? -          To what extent is the environment on mafic bedrock, or in its proximity, often judged as worth protecting? The theoretical basis for the study is soil formation regarding parent material, based on Jenny´s formula, and weathering according to the Goldich dissolution series. The method used is a comparison between maps showing bedrock and maps showing areas with protected nature. The protected areas are considered as connected to the mafic bedrock if they are within the mafic area, or up to 2 km from the mafic area in the direction of the ice movement during the last ice age (Weichsel) in Sweden. The mainland of the municipality of Oskarshamn, on the southeast coast of Sweden, is used for a case study. The bedrock in this area is mainly felsic, with some minor areas being mafic. The result shows a higher degree of protected nature, for the types “naturreservat” and ”Natura 2000”, on mafic bedrock, or in the vicinity of the mafic area, than for felsic bedrock. The result for Oskarshamn is compared to mafic bedrock areas around Åseda and Fagerhult and to the limestone area around Vintrosa. For all of these three cases there are areas of protected environment, within or in the vicinity of the studied bedrock areas. Although there seems to be a relationship between mafic bedrock and protected nature, other factors need to be considered as well. The influence of topography, access to water, local climate and e.g. the particle size of the soil, may contribute considerably to the content and distribution of the vegetation at a specific place.

Problems with erosion in unlined spillways of dams, have caused environmental and safety hazards, and necessitate the development of reliable scientific methods to assess the erodibility of the bedrock material. In an attempt to analyze the causes and effects of different geological, geotechnical, hydraulic, hydrological and engineering design parameters on erosion of unlined spillways, a number of dam spillways in the R.S.A. were studied. All the parameters considered important for the erosion resistance of the rock were collected and correlated with hydraulic factors and observed extent of erosion. Rock type, strength, weathering and uniformity of the geological conditions are important geotechnical considerations while velocity and energy of the water flow are the main hydraulic parameters. The main consideration of the study was the effect of the discontinuities. All the properties of the jointing of the rock mass, such as number of joint sets, RQD, joint spacing, joint separation, joint orientation, roughness and filling material, were surveyed. Joints. weaken the rock mass and induce removal of the rock blocks if the joint properties are unfavourable to stability. The jointed bedrock is much less resistant to flowing or falling water, the result being an extensive and quickly formed scour. Various rock mass classification systems have been applied and a reasonable correlation between rock class and extent of erosion was established by means of slightly modified Kirsten (1982) and Weaver (1975) rippability classifications. A number of methods for the prevention and repair of erosion damage have been proposed. / Dissertation (MSc)--University of Pretoria, 1990. / gm2014 / Geology / unrestricted

The Gautrain Rapid Rail Link is a state-of-the-art rail route and one of the ten Spatial Development Initiatives planned in Gauteng Province, South Africa. The route comprises two links, namely a link between Tshwane (Pretoria) and Johannesburg and a link between OR Tambo International Airport and Sandton. A total of 10 stations are linked by approximately 80 kilometres of rail along the proposed route. Between Johannesburg and Pretoria in the southern Tshwane region, the rail alignment is underlain by dolomite bedrock for approximately 15km in the vicinity of Centurion between Nelmapius Drive and The Fountains, including nearly 6km elevated on a viaduct. The stability of the rapid rail link constructed over the dolomitic sections was considered a major project risk due to its proneness to sinkholes and subsidences along this route. Construction on heterogeneous soils, pinnacled bedrock and other geohazards posed major challenges to the construction team. To facilitate detailed design and adapt proper foundation options for the viaducts founded over the dolomitic terrain, rigorous and comprehensive ground investigations were conducted by the Bombela Civils Joint Venture (BCJV). This work presents the different ground investigation methods used and how the results have led to the adoption of five suitable foundation solutions namely: large diameter shafts to rock, piles to rock, floating foundations over grouted ground, spread footings on shallow bedrock and concrete U shaped structures. Additional information available on a CD stored at the Merensky Library on 3rd Floor / Dissertation (MSc)--University of Pretoria, 2012. / Geology / unrestricted

In underground construction and foundation engineering uncertainties associated with subsurface properties are inevitable to deal with. Site investigations are expensive to perform, but a limited understanding of the subsurface may result in major problems; which often lead to an unexpected increase in the overall cost of the construction project. This study aims to optimize the pre-investigation program to get as much correct information out from a limited input of resources, thus making it as cost effective as possible. To optimize site investigation using soil-rock sounding three different sampling techniques, a varying number of sample points and two different interpolation methods (Inverse distance weighting and point Kriging) were tested on four modeled reference surfaces. The accuracy of rock surface predictions was evaluated using a 3D gridding and modeling computer software (Surfer 8.02®). Samples with continuously distributed data, resembling profile lines from geophysical surveys were used to evaluate how this could improve the accuracy of the prediction compared to adding additional sampling points. The study explains the correlation between the number of sampling points and the accuracy of the prediction obtained using different interpolators. Most importantly it shows how continuous data significantly improves the accuracy of the rock surface predictions and therefore concludes that geophysical measurement should be used combined with traditional soil rock sounding to optimize the pre-investigation program.

The role of bedrock on the longitudinal profile of the Colorado River has intrigued workers for over a century. The river's profile exhibits large-scale (10 to 100 km) variations in geomorphology that are qualitatively associated with changes in rock type. This study provides the first bedrock-strength data to quantitatively test the relation of bedrock-resisting to hydraulic-driving forces in Glen and Grand canyons. The intent of this study is to explore the role, if any, that bedrock has on large-scale geomorphic variations along the profile of the Colorado River. Rock-strength data collected at 84 sites along the river corridor in Glen and Grand canyons include intact-rock strength, fracture spacing , and other characteristics associated with Selby rock-mass strength (RMS). These strength data were statistically related to measurements of channel width, gradient, and calculations of unit stream power. At the canyon scale (100 km), rocks in Grand Canyon have significantly higher intact-rock strength, lower fracture spacing, and higher RMS than those in Glen Canyon. These observations correspond to the fact that Grand Canyon is steeper and narrower, and has greater mean unit stream power. Furthermore, smaller scale, reach-average values of rock strength correlate significantly to width, gradient, and unit stream power, although there are outliers related to local-scale effects such as rapids. The Colorado River runs in a narrower and steeper channel in reaches confined by resistant bedrock ( e.g., Upper Granite Gorge, RM 77-114). In contrast , reaches floored in weaker bedrock (e.g., lower Marble Canyon, river miles 37 to 58) are associated with wider channels and lower gradient. This study confirms previous research linking rock type to the geomorphology of the Colorado River. Results imply that knickzones in the profile are persistent features that reflect a dynamic equilibrium between hydraulic-driving and bedrock-resisting forces, rather than transient waves of incision due to tectonics or drainage integration. They support the hypothesis that bedrock sets the long-term, large-scale template for the Colorado River. Bedrock hypothetically acts as a direct control on the river's width and gradient, particularly when the river is in contact with bedrock. Rock-strength and weathering properties of bedrock within tributary catchments, where debris flows initiate, act as an indirect control through their influence on hillslope-to-river sediment production during episodes, such as today, when the river is not on bedrock.

Urbanized areas with increased amounts of impervious surfaces alter hydrologic systems by increasing stormwater runoff, decreasing infiltration, and reducing vegetation cover and evapotranspiration. Modeling hydrologic systems here is especially difficult due to the increased impervious land cover, which makes predicting processes such as urban streamflow and flooding challenging. By understanding the drivers of hydraulic processes, such as soil characteristics, bedrock depth, and land use, the quality and accuracy of models can be improved. The goal of this study was to use soil moisture loggers and electrical resistivity tomography (ERT) along the Pennypack Creek (Philadelphia, PA) to evaluate soil infiltration and bedrock depth in urban areas to ultimately access their impact on critical zone modeling. ERT was also used to validate or dispute recent seismic interpretations. Four study sites adjacent to Pennypack Creek were selected based on variations in underlying geology: Triassic basin sedimentary rock (Lukens), Paleozoic mafic gneiss (Meadow), Piedmont mica schist (Pine Road), and coastal plain weathered down to mica schist (Rhawn Street). Soil moisture sensors were installed at each site to a depth of up to 50 cm. ERT surveys were conducted at Pine Road and Rhawn Street sites. High infiltration variation at Pine Road and Meadow indicated macropores, which create preferential flow paths whereas low infiltration variation at Rhawn Street and Lukens indicated compaction associated with their land use (public parks). Comparing field capacity data to USDA soil type maps indicated the soil type was not a good predictor and in situ sampling was needed to estimate soil properties. ERT demonstrated bedrock was not shallow at the streambed as predicted by the seismic inversion and showed the need to corroborate depth to bedrock from seismic surveys beneath streams with resistivity inversions. Structure beneath the streambed was particularly noisy for the seismic surveys due to the flow of stream water. This study demonstrates that an accurate critical zone model, especially at urban sites, must rely on in situ investigation of hydrologic parameters based on land use, rather than assumptions of parameter values based on the underlying geology or soil type. / Geology

<p> The Paleozoic bedrock surface of southern Ontario is dissected by an interconnected system of buried bedrock valleys that are infilled with thick successions of glacial, interglacial and fluvial sediments. These valleys can be several kilometers wide, reach depths of up to 250m and the coarse-grained units are known to host significant local and regional groundwater aquifers.</p> <p> Two buried bedrock valleys located near the Niagara Escarpment in the Region of Halton were under investigation in the fall of 1999 for their potential to host additional municipal groundwater aquifers to supply drinking water to the towns of Milton and Georgetown. Detailed logging of sediment recovered from eleven continuously-cored boreholes, drilled within the Georgetown and Milton bedrock valleys, forms the basis for this study. Four distinct facies types were identified within the borehole cores including sand, gravel, fine-grained sediment and diamict (sand-rich, mud-rich and clast-rich). These four facies types were used to subdivide the cores into six stratigraphic units based on textural characteristics and stratigraphic position. These six units form a stacked succession of aquifers and aquitards within the valley infill with two stratigraphic units being identified as potential municipal aquifers.</p> <p> The Georgetown buried bedrock valley contains narrow bedrock channel interpreted to have been fluvially incised, lying within a broader flat-bottom valley likely formed by glacial scouring of the bedrock. It is feasible that regional bedrock jointing created a zone of weakness that was later exploited by a drainage network. The valley infill sediments record the approach of the Laurentide Ice Sheet into southern Ontario during the Early to Mid-Wisconsin, and the subsequent overriding of the area during the Late Wisconsin period.</p> / Thesis / Master of Science (MSc)