1,679 research outputs found
Karst, GIS and geological hazard planning and management in Great Britain
The British Geological Survey (BGS) database of karst features for the United Kingdom include dolines, cave entrances, stream sinks, resurgences and building damage; data for approximately half of the country has so far been gathered. BGS makes and utilises digital geological map data, which includes lithological and stratigraphical information for bedrock and superficial deposits. By incorporating this digital map data with digital elevation slope models and karst data, BGS has generated a derived dataset assessing the likelihood of subsidence due to karst collapse. This dataset is informed and verified by the karst database and marketed as part of its GeoSure suite; the karst layer includes areas of limestone, chalk, gypsum and salt. It is currently used by environmental regulators, the insurance and construction industries plus the BGS semi-automated enquiry system. The karst database and GeoSure datasets can be combined and manipulated using GIS to make other datasets that deal with specific problems. Sustainable drainage systems, some of which use soak-aways into the ground are being encouraged in the UK, but in karst areas they can cause problems. Similarly, open loop ground source heat pumps may induce subsidence if installed in certain types of karst such as chalk with overlying sand deposits. Groundwater abstraction also has the potential to trigger subsidence in karst areas. GIS manipulation of the karst information will allow the UK to be zoned into areas suitable, or unsuitable, for such uses; it has the potential to become part of a suite of planning management tools for local and National Government to assess the long term sustainable use of the ground
Land use planning for high pressure pipelines : ground hazards from dissolution of soluble rocks
The overall permeability of each geological unit has been interpreted to produce an index of the
vulnerability of groundwater occurring in Glasgow, and provides a broad-based view of both the
vulnerability of groundwater and the location of the more permeable aquifers in Glasgow.
The data used to interpret the groundwater vulnerability index are derived from the 1:50 000
DigMap bedrock and superficial geology coverage. The GIS and associated maps should not
therefore be used at scales larger than 1:50 000. Locations of thick clays have been interpreted
and drawn based on BGS borehole records. Information on water boreholes is derived from the
British Geological Survey Scottish Water Borehole database
A log analysis study of 10 years of ebook consumption in academic library collections
Even though libraries have been offering eBooks for more than a decade, very little is known about eBook access and consumption in academic library collections. This paper addresses this gap with a log analysis study of eBook access at the library of the University of Waikato. This in-depth analysis covers a period spanning 10 years of eBook use at this university. We draw conclusions about the use of eBooks at this institution and compare the results with other published studies of eBook usage at tertiary institutes
BGS Karst Report Series: P1. Karst in the northern outcrop of Permian limestones
This report documents the evidence for karst and rapid groundwater flow in the northern outcrop of the Permian dolomitic limestones and their associated gypsum sequences in County Durham and a small part of North Yorkshire, in northern England. It is part of the BGS karst report series on those karst aquifers in England in which cave development is limited â principally the Upper Cretaceous Chalk and the Jurassic and Permian limestones. The term âkarstâ applies to rocks that are soluble. In classic karst there are extensive caves and large-scale surface karst landforms such as dolines, shafts, stream/river sinks, and springs. In the past, the Chalk and the Jurassic and Permian limestones of England were not considered karstic because they have limited cave development, and because karst features are usually small and have not been well documented. The reports provide data and information on karst in each area.
There is clear evidence for karstic development in the Permian dolomitic limestones in the P1 area. Some short caves occur which appear to be fully or partially karstic in origin, and although they are now predominantly dry, they demonstrate that cave sized voids can develop in the limestones. Other caves and voids related to mass-movement are also present. There are also smaller karstic conduits, solutional fissures, dolines, dissolution pipes, stream sinks and springs present. However, there are no comprehensive datasets on these features and information on their frequency, distributions and characteristics is generally scarce. There is some further evidence that karstic networks of solutional fissures and conduits occur in the saturated zone, with some high transmissivities and yields, and large fissure inflows during construction. Both the unsaturated and saturated zones of the aquifer are impacted by karst, with a proportion of rapid recharge via surface karst features and solutional fissures, as well as some saturated zone networks of solutional conduits and fissures. These networks are likely to result in groundwater flow in unexpected directions and potentially over long distances. Considerable further work is needed to develop better datasets on karst features, and to assess the role of karst in the limestones in this area. There is more information on gypsum karst in the area, which is well-developed and poses significant engineering hazards and challenges, and also impacts on the limestones which collapse into the gypsum karst. The presence of sulphate-rich groundwater and springs indicate the interconnection of limestone and gypsum sequences in the Permian strata in the area, highlighting the complexity and connectivity between different geologies
BGS karst report series : P2. Karst in the southern outcrop of Permian limestones (and associated gypsum)
This report documents the evidence for karst and rapid groundwater flow in the southern outcrop of the Permian limestones in Northern England, together with the associated gypsum karst. It is part of the BGS karst report series on those karst aquifers in England in which cave development is limited â principally the Upper Cretaceous Chalk and the Jurassic and Permian limestones. The term âkarstâ applies to rocks that are soluble. In classic karst there are extensive caves and large-scale surface karst landforms such as dolines, shafts, stream/river sinks, and springs. In the past, the Chalk and the Jurassic and Permian limestones of England were not considered karstic because they have limited cave development, and because karst features are usually small and have not been well documented. These reports provide data and information on karst in each area.
The Permian dolomitic limestones comprise the Cadeby Formation and the Brotherton Formation. These formations are separated by the Edlington Formation and overlain by the Roxby Formation, both of which contain extensive evaporite karst (in gypsum and anhydrite) interspersed with low permeability mudstones penetrated by karstic collapse features. This report is primarily focused on the dolomitic limestone karst, but the variable geology results in high complexity with interactions between the limestone and evaporite karst. Karst in the Permian gypsum associated with the limestones has not been well-recognised in hydrogeological studies. Evaporite karst in the area is well developed and documented with caves, dolines, and dissolution pipes. Collapse features extend into the limestones, especially in the Brotherton Formation, and there is evidence of groundwater connectivity between the evaporite and limestone karst, for example with sulphate-rich groundwater in the limestones and overlying strata. The gypsum sequences in contact with the limestones result in locally very high transmissivities and mixing of waters from the two types of karstified rocks.
There is also clear evidence for karstification within the dolomitic limestones. Quite large, although short and dry, dolomitic limestone caves occur in the Cadeby Formation, with 21 karst caves recorded, ranging from 2.5 to 290 m in length. There is also evidence that smaller solutional conduits and fissures occur in the limestones which are likely to be an important component of groundwater flow. There are many other caves, some of which are formed by mass movement (slip rift caves) and some for which it is unclear whether they are mass movement caves or karst caves. In some instances, slip rift caves form a focus for recharge to the limestones, but many may be largely dry. There are significant karst stream sinks into the Cadeby Formation at Wadworth Wood near Doncaster and near Darrington, and a major karst river sink into the Cadeby Formation on the River Skell. Some limestone dolines and dissolution pipes have been recorded in the Cadeby and Brotherton formations. There are large numbers of springs in the Permian limestones, and although their flows and characteristics are generally not well documented, it appears that many are quite small, and a few may have substantial flows. Tracer tests have been carried out at one location, and these demonstrated connectivity between a groundwater abstraction and both a leaking sewer and a surface water course, over distances of 10s to 100s metres. At this locality high transmissivity, and high yields (> 80 l/s) also indicate solutional development of permeability. There are other abstractions in the P2 area with high yields and transmissivities of > 1000 m2/day suggesting they may be supplied by karstic solutional networks. Detailed borehole investigations using slug tests and water level monitoring have revealed rapid flow velocities of 13 to 242 m/day in the Cadeby Formation at the Leeds University study site, and modelling work over a wider area suggested very rapid flows of up to 9000 m/day (Medici et al 2019a,b). These studies also showed that very low effective porosities (2.8 x 10-4) are needed to represent the karstic development of permeability in the Permian limestones and the potential large scale of contaminant transport.
The data collated in this report demonstrate that a component of unsaturated zone flow in the Permian limestones is rapid, but the proportion of rapid flow, and the frequency of rapid flowpaths that extend through the entire unsaturated zone, is uncertain. Evidence of cave, conduit and solutional fissure development; and some high transmissivities and high borehole yields, especially where gypsum is present, suggest that there are saturated zone networks of solutional fissures and conduits which might enable pollutant transport over long distances and in unexpected directions, but further work is needed to determine how frequently these networks occur and how extensive they are. Such networks can form along stream sink to spring flowpaths or through mixing corrosion. Overall, this report highlights the importance of karst in the Permian limestones, the complexities of the interactions with the evaporite karst, and the need for further development of karst datasets and conceptualisation of the karst hydrogeology to assist with groundwater studies and management in this area
String Cosmology: A Review
We give an overview of the status of string cosmology. We explain the
motivation for the subject, outline the main problems, and assess some of the
proposed solutions. Our focus is on those aspects of cosmology that benefit
from the structure of an ultraviolet-complete theory.Comment: 55 pages. v2: references adde
Shape invariance method for quintom model in the bent brane background
In the present paper, we study the braneworld scenarios in the presence of
quintom dark energy coupled by gravity. The first-order formalism for the bent
brane (for both de Sitter and anti-de Sitter geometry), leads us to discuss the
shape invariance method in the bent brane systems. So, by using the
fluctuations of metric and quintom fields we obtain the Schrodinger equation.
Then we factorize the corresponding Hamiltonian in terms of multiplication of
the first-order differential operators. These first-order operators lead us to
obtain the energy spectrum with the help of shape invariance method.Comment: 13 pages, no figur
Egg yolk fatty acid profile of avian species - influence on human nutrition
Lipids are an important nutritional component of the avian egg. A
review of the literature was completed to determine the fatty acid compositions
in egg yolk from some avian species. Additionally, the nutritional
influence of lipid and lipoprotein content on the plasma of male
participants during 30-day feeding was discussed. The ostrich eggs had
the highest unsaturated fatty acid and the lowest cholesterol content in
relation to other avian species. Ostrich had a higher proportion of
18:3n-3 (p < 0.01) compared with other species. Chicken yolk numerically
contained much higher levels of 22:6n-3 than those found in turkeys,
quails and geese, but the amount of 22:6n-3 in ostrich egg was
lower by comparison with other species (p < 0.01). After the storage of
eggs at the room temperature, there was a notable loss of vitamin E
(vitE) in the yolks of all species and this decrease was marginal
(p < 0.01) in ostrich compared with other species. There were significant
(p < 0.05) increases in plasma low-density lipoprotein (LDL) level in all
male subjects. Plasma high-density lipoprotein (HDL) level decreased
(p < 0.05) only in men who were fed chicken or ostrich eggs daily. Consumption
of different speciesâ eggs had no influence on the total male
plasma cholesterol and triglyceride levels. LDL-C:HDL-C ratio increased
(p < 0.05) after goose and turkey egg consumption. Consumption of one
egg/month by healthy human subjects had no effect on serum total cholesterol
and triglyceride. The LDL-C:HDL-C ratio (which is a strong
predictor of coronary heart disease risk) increased, although non-significantly,
by consuming chicken, quail and ostrich eggs.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1439-0396hb201
Assessing the feasibility and value of employing an ecosystem services approach in chemical environmental risk assessment under the Water Framework Directive
The feasibility and added value of an ecosystem services approach in retrospective environmental risk assessment were evaluated using a site-specific case study in a lowland UK river. The studied water body failed to achieve good ecological status temporarily in 2018, due in part to the exceedance of the environmental quality standard (annual average EQS) for zinc. Potential ecosystem service delivery was quantified for locally prioritised ecosystem services: regulation of chemical condition; maintaining nursery populations and habitats; recreational fishing; nature watching. Quantification was based on observed and expected taxa or functional groups within WFD biological quality elements, including macrophytes, benthic macroinvertebrates and fish, and on published functional trait data for constituent taxa. Benthic macroinvertebrate taxa were identified and enumerated before, during and after zinc EQS exceedance, enabling a generic retrospective risk assessment for this biological quality element, which was found to have good ecosystem service potential. An additional targeted risk assessment for zinc was based on laboratory-based species sensitivity distributions normalised using biotic-ligand modelling to account for site-specific, bioavailability-corrected zinc exposure. Risk to ecosystem services for diatoms (microalgae) was found to be high, while risks for benthic macroinvertebrates and fish were found to be low. The status of potential ecosystem service delivery (ESD) by fish was equivalent to high ecological status defined under the WFD, while ESD was higher for benthic macroinvertebrates than defined by WFD methods. The illustrated ecosystem services approach uses readily available data and adds significantly to the taxonomic approach currently used under the WFD by using functional traits to evaluate services that are prioritised as being important in water bodies. The main shortcomings of the illustrated approach were lack of: representation of bacteria and fungi; WFD predicted species lists for diatoms and macrophytes; site-specific functional trait data required for defining actual (rather than potential) ecosystem service delivery
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