bluuebunny/crossref_metadata_2025_split huggingface dataset:
Delineating the horizontal and vertical extent of hydrocarbon contamination using laser induced UV fluorescence
Authors: Hughes J. P. , Taer A. D. 
Published: April 2008

Abstract

Before we can hope to successfully conduct a risk assessment, or select the proper technology for remediation at a contaminated site, we must first have a thorough understanding of the nature of the impacts at that site. This paper will present an overview of a field-proven,
in situ
site assessment technique based on laser induced UV fluorescence, that provides continuous, real time information on the distribution of hydrocarbons in the subsurface. The system can detect hydrocarbons regardless of whether they are located above or below the water table, and it gathers the data without generating any cuttings that could require costly disposal. This technology can also provide a qualitative ‘fingerprint’ of the hydrocarbons present at the site. Since the data are available in real time, adjustments to the site assessment programme can be made in the field. Examples of applications of this technology include using it as a screening tool to delineate both the horizontal and vertical extent of hydrocarbon contamination; estimating the volume of contaminated soil that may have to be addressed; or helping to select locations for more expensive confirmatory soil samples or permanent monitoring wells. Actual data from a number of sites will be presented to illustrate some of these applications.
Modelling biodegradation in a groundwater environment: choosing an appropriate method
Authors: Davison Ruth M. , Lerner David N. 
Published: April 2008

Abstract
The transport of contaminants through aquifers is a complex issue affected by advection, dispersion, sorption and biodegradation. Biodegradation is the only process which allows the contaminant mass naturally to be physically reduced. Due to the quantity of contaminated sites and the expense of remediation schemes it is essential to understand the natural attenuation provided by biodegradation. Modelling of the biodegradation processes provides not only the means to a fuller understanding of a plume's development but also the facility to test potential remediation schemes. A two-tier classification system is presented which summarizes the current literature regarding the modelling of biotransformations in saturated porous media. The first relates to the treatment of the physical microbial setting and the second tier relates to the reaction approach. The physical setting tier is discussed in the context of biofilms. The basic theory and various types of biofllm are summarized while discussing the evidence for and against the necessity of representing biofilms in biotransformation models. The techniques implemented to model biofilms are summarized, including the limitations and previous and potential applications. The reaction tier constitutes four sections: first-order decay models, instantaneous reaction models, Monod kinetic models and Michaelis—Menton kinetics. For each of the reaction approaches a physical and mathematical description is provided with an explanation of its relevance for the modelling of biotransformations. An approach for selecting the appropriate modeling techniques is illustrated for a contaminated site.
Contamination of sediments in the Forth Estuary, Scotland
Authors: Lindsay P. , Bell F. G. , Hytiris N. 
Published: April 2008

Abstract

This paper considers the contamination of sediments in the Forth Estuary. When trace metals are released into the water column they can be transferred rapidly to the sediment phase by adsorption onto suspended particulate matter, to be followed by sedimentation. Intertidal flats may be considered as important trace metal sinks since they accumulate large amounts of suspended matter. Hence, in polluted estuaries the deposition of suspended particles on intertidal flats may thus cause severe contamination. The Forth Estuary has unique contamination for British estuaries: it is experiencing significant Hg pollution. In addition, due to the presence of a nuclear submarine base in the Forth Estuary, Co
60
is detectable in the intertidal sediments. Temporal and spatial contamination patterns were analysed in relation to historical and present pollution point sources.
Estimation of solid phase activity coefficients for non-ideal cation exchange behaviour in laboratory samples of UK Triassic sandstones
Authors: El-Ghonemy H. 
Published: April 2008

Abstract

A traditional laboratory method for measuring cation exchange parameters was applied to plugs of Triassic sandstone core. The objective of the study was to measure cation exchange capacities and selectivity coefficients in the Ca—Mg−Na—K system in intact rock samples, and to investigate the extent to which the system departs from ideality. The method involved the use of NH
4
Cl as a high ionic strength exchange salt solution in column experiments. Non-ideal behaviour was observed, being most obvious for the K—Na, K—Mg and K—Ca exchange systems. Activity coefficients for the exchanger phase were estimated and a dependence on the composition of the exchanger was recognized. An equation for exchange equilibria is proposed where this dependence is accounted for in the form of a power function.
An initial evaluation of Synperonic PE surfactants as soil washing agents
Authors: Paterson Iain F. , Chowdhry Babur Z. , Leharne Stephen A. 
Published: April 2008

Abstract
The utility of the Synperonic PE range of block copolymeric nonionic surfactants in the decontamination of soil is systematically investigated. In the case of the solubilization of naphthalene in the absence of soil by the six Synperonic PE surfactants studied, the molar solubilization ratio (MSR), which is a measure of the solubilizing power of surfactants in their aggregated (i.e. micellar) form, broadly increases with an increase in the weight percentage content of the hydrophobic polypropylene oxide portion of the surfactant. Significantly, solubility enhancements are substantial even below the tensiometrically determined critical micelle concentration. The sorption of a number of these surfactants onto a soil of organic carbon content 0.6% is shown to be described by Freundlich isotherms, and is significant, adding considerably to the organic content of the soil. However, the surfactants substantially reduce the soil-water partition coefficient of naphthalene, phenanthrene and pyrene, indicating that they may potentially find applications in soil decontamination.
High-altitude glacial lake hazard assessment and mitigation: a Himalayan perspective
Authors: Reynolds John M. 
Published: April 2008

Abstract
Glaciers throughout the Himalayas have been receding rapidly over the last few years. In the areas vacated by the ice snouts lakes have formed behind large moraine dams. As with their Andean counterparts, these lakes can pose significant threats to downstream towns, roads and power schemes. For a developing country like Nepal, for example, the prospective loss of economically vital infrastructure and food-producing land can be devastating, in addition to the human misery.

The Tsho Rolpa glacier lake has formed by the retreat of Trakarding Glacier at the head of the Rolwaling Valley in northern Nepal. The lake is now over 3 km long and contains an estimated volume of 80 x 10
6
m
3
. The snout of Trakarding Glacier terminates in the lake which, at its western end, is dammed by an ice-cored moraine. It is feared that the lake could be the source of a major glacier lake outburst flood (known locally as a ‘GLOF’) which could destroy the nearby villages of Na and Beding, as well as trekking routes, vital bridges,
etc.
, further downstream. At Khimti, 80 km downstream from Tsho Rolpa, a new hydroelectric power scheme is being built and could potentially be at risk.

It is known that the local glaciers in the Rolwaling Valley have been the source of many GLOFs in historical as well as contemporary times. The last GLOF destroyed several houses and valuable farm land at Beding in July 1991.
Following an initial GLOF-risk assessment in September 1994, a trial siphon was installed at Tsho Rolpa in May 1995. This is the first time that such measures have been used in the Nepalese Himalayas. Since then further remediation measures have been proposed and are awaiting funding. The nature of the glacial hazards at Tsho Rolpa and the engineering mitigation measures being proposed are described. Furthermore, it is concluded that an integrated national policy on glacial hazards should be developed urgently.
Coastal cliff behaviour and management: Blackgang, Isle of Wight
Authors: Moore R. J. , Clark A. R. , Lee E. M. 
Published: April 2008

Abstract
In January 1994 coastal erosion and landslide activity at Blackgang, Isle of Wight, resulted in a dramatic retreat of the coastal cliffs and landward extension of ground movement. The initial impact of the event involved the destruction of two cottages, an access road, several cars and caravans, and around 12 homes had to be evacuated. The event raised considerable local and national media attention.
The initial landslide response was co-ordinated by South Wight Borough Council, with advice from Rendel Geotechnics, and was aimed at ensuring public safety and security in the area. A detailed investigation was subsequently carried out to identify the extent and causes of coastal instability and cliff recession in the context of ‘cliff behaviour units’. An understanding of the characteristic cliff behaviour units has proved the key to assessing future landslide and cliff recession potential as well as identifying options for coastal cliff management at Blackgang.
The coastal cliffs have been significantly oversteepened by the latest events and appear to be very sensitive to rainfall, with only relatively moderate to high winter rainfall totals expected to cause further cliff-top retreat and landslide reactivation. Consequently, in the absence of a financially and environmentally acceptable slope stabilization and coast protection scheme, continued managed retreat of cliff-top development and land use is seen as the only viable option.
Engineering hazards in the Taroko Gorge, eastern Taiwan
Authors: Petley D. N. 
Published: April 2008

Abstract
The population of Taiwan is concentrated on the low-lying coastal strips, separated by the Central Mountains. Whilst communication across the island is economically essential there are only three usable roads. This paper investigates natural hazards on the easternmost section of one of these roads, the Central Cross Island Highway. In the study area the road follows the base of the 600 m deep Taroko Gorge in a series of tunnels and rock ledges. The road is heavily used for transport whilst the gorge is one of the nation’s premier tourist attractions.
Maintenance of the road in Taroko Gorge represents a profound challenge to the engineering geologist. The walls of the gorge are composed of deformed marble, gneiss and schist and are prone to failure under the intense seismic activity. Additionally the area is prone to an average of three to four tropical cyclones per annum, with up to 1200 mm of rainfall in each.
A detailed geomorphological and engineering survey of the gorge has been undertaken. The data are analysed along with information obtained from the highway maintenance board. It is demonstrated that during typhoons the area suffers an unusually severe set of geological hazards. The heavy rainfall initiates rockfalls and landslides along the gorge. Flooding occurs widely both as a result of the increased discharge of the river and as a result of water cascading onto the road from the adjacent cliffs. The destruction of important bridges may also occur. An examination is made of the magnitude of these hazards, and techniques used by the highway authority are described and analysed in relation to the use of the road for both transport and tourism.
Mitigating geohazards affecting mountain roads in northeast Somaliland
Authors: Nathanail Paul , Nathanail Judith 
Published: April 2008

Abstract
Roads linking the Gollis plateau with sea ports on the Gulf of Aden descend a steep escarpment. The roads are continually affected by erosion and degradation. These usually gentle processes constitute significant geohazards to the communities on the plateau which rely on the roads to export their agricultural produce as they attempt to rebuild the local economy following years of civil war. Engineering geological advice was provided to local communities involved in maintaining and repairing three roads, in areas occupied by different Somali clans. The absence of advice at an earlier stage had resulted in much wasted effort in inappropriate realignments and gradients.
By tailoring the advice to the materials, tools and skills available locally, one road could be re-opened and two could be significantly improved, reducing travel times for laden lorries by up to half.
A hazard map of the Magnesian Limestone in County Durham
Authors: Green M. R. , Forth R. A. , Beaumont D. 
Published: April 2008

Abstract
A large part of County Durham is underlain by carbonate rocks of Permian age, principally Magnesian Limestone. In recent years problems have been encountered in constructing on the Permian carbonates, due to dissolution followed by subsidence and/or sink hole formation.
Features believed to be triggers for dissolution of limestone have been mapped and a weighted factor hazard map has been created. The map is based on an extensive review of existing site investigation data including a study of aerial photographs. Records of dissolution features noted by the County Council engineers have been incorporated into the hazard map. The map is intended as a guide for County Council Engineers who are planning site investigations within the area. The preparation of the map and its limitations are discussed.
Landslide susceptibility mapping using the Matrix Assessment Approach: a Derbyshire case study
Authors: Cross Martin 
Published: April 2008

Abstract
Civil engineering schemes such as new highways and railway lines, regional planning and large-scale land-management projects in areas known to have a landslide problem require regional landslide susceptibility evaluation. The Matrix Assessment Approach (MAP) is introduced as a medium-scale landslide hazard mapping technique for establishing an index of slope stability over large areas. The method allows the relative landslide susceptibility to be computed over large areas using a discrete combination of geological/geomorphological parameters. MAP was applied to a region in the Peak District, Derbyshire. The model identified key geological/geomorphological parameters involved in deep-seated failures, provided an effective means of classifying the stability of slopes over a large area and successfully indicated sites of previously unmapped landslides. The resultant regional landslide susceptibility index provides useful preliminary information for use at the desk study and reconnaissance stages of large-scale civil engineering works such as highway construction.
Subsidence hazards caused by the dissolution of Permian gypsum in England: geology, investigation and remediation
Authors: Cooper A. H. 
Published: April 2008

Abstract

About every three years natural catastrophic subsidence, caused by gypsum dissolution, occurs in the vicinity of Ripon, North Yorkshire, England. Holes up to 35 m across and 20 m deep have appeared without warning. In the past 150 years, 30 major collapses have occurred, and in the last ten years the resulting damage to property is estimated at about £1000000. Subsidence, associated with the collapse of caves resulting from gypsum dissolution in the Permian rocks of eastern England, occurs in a belt about 3 km wide and over 100 km long. Gypsum (CaS0
4
.2H
2
0) dissolves rapidly in flowing water and the cave systems responsible for the subsidence are constantly enlarging, causing a continuing subsidence problem.

Difficult ground conditions are associated with caves, subsidence breccia pipes (collapsed areas of brecciated and foundered material), crown holes and post-subsidence fill deposits. Site investigation methods that have been used to define and examine the subsidence features include microgravity and resistivity geophysical techniques, plus more conventional investigation by drilling and probing. Remedial measures are difficult, and both grouting and deep piling are not generally practical. In more recent times careful attention has been paid to the location for development and the construction of low-weight structures with spread foundations designed to span any subsidence features that may potentially develop.
Digital image texture analysis for landslide hazard mapping
Authors: Mason P. J. , Rosenbaum M. S. , Moore J. McM. 
Published: April 2008

Abstract
Textural enhancements using co-registered, multi-temporal, digital remotely sensed imagery have been used to study slope instability at three landslide localities. The remotely sensed imagery consists of Landsat TM, SPOT Pan and Daedalus 1268 Airborne Thematic Mapper (ATM); stereo, black and white aerial photographs have also been used. Image processing provides spatial and textural information concerning landform change, landslide location and morphology. The enhanced imagery can be integrated with digital elevation models (DEMs), as can other map and geotechnical data, into a GIS to analyse quantitatively the effect of slope geometries on the observed landsliding. The suitability of available imagery depends upon the type and scale of the study and the landslide dimensions. The case histories have shown that spatial resolution is the most important parameter for successful landslide identification. The optimum imagery is provided by a combination of textural and spectral enhancements using different types of imagery.
Acid mine drainage and pollution: two case histories from South Africa
Authors: Bell F. G. , Bullock S. E. T. , Geldenhuis S. 
Published: April 2008

Abstract
Different types of waste waters and effluents may be produced as a result of mining. They arise due to the extraction or preparation of the mineral deposit or from the disposal of associated spoil. Generally the major pollutants are suspended solids, dissolved salts or acidity. In the latter case acid mine drainage refers to the oxidation of sulphide minerals, notably pyrite, which are exposed in the mine or are present in the spoil. The primary oxidation products of pyrite are ferric and ferrous sulphates, and sulphuric acid. Two case histories are provided which deal with the problem of acid mine drainage associated with mines in South Africa. The first refers to a tin mine in the Transvaal where acidic waters were produced by heaps of pyrite discard. As the mine was due to close, the problem of possible groundwater pollution due to acid mine drainage had to be investigated as part of the environmental management programme. The second case history involves a coal mine in the Eastern Transvaal which was seeping an appreciable load of acidic effluent and salts into the headwaters of the Vaal River, which is a major source of water to the main industrial conurbation of the country. Investigations which included a study of the history of the site, geology, geophysics, hydrology, hydrogeology and geochemistry succeeded in clarifying the sources of the acidic seepage and the remedial measures that would have the greatest chance of success.
Improved methods for developing and visualizing remediation strategies
Authors: Hatton W. , Hunter G. , Hall D. , Haigh D. 
Published: April 2008

Abstract
Remediation of contaminated sites can be both costly and time-consuming. In order to ensure that a cost-effective remediation method is selected, several options are usually considered. VULCAN, a 3D modelling package, has been used to demonstrate the development and visualization of remediation strategies using site assessment data.
At a former chemical manufacturing facility, 71 samples were collected from 31 boreholes. Concentrations of the contaminant were measured in all samples and visualized using the 3D package.
Remedial options were considered and a benefit analysis performed. This considered positive benefits, such as attainment of clean-up levels, and negative benefits, such as excavation and associated costs. Optimization of the most cost-effective method was then performed using the Lerchs-Grossman algorithm.
Development of ‘rockhead’ computer-generated geological models to assist geohazard prediction in London
Authors: Strange P. J. , Booth S. J. , Ellison R. A. 
Published: April 2008

Abstract
Much of London is founded on Quaternary river terrace deposits, consisting mainly of sand and gravel associated with the course of the River Thames. The base of these Quaternary river terrace deposits, the ‘rockhead’ surface, is generally planar and rests on London Clay. Locally, however, the terraces may include steep-sided, gravel-filled hollows, some of which penetrate other solid formations below the London Clay, such as the Lambeth Group (formerly known as the Woolwich and Reading Beds).
Unforeseen engineering problems involving deep foundation construction or tunnelling beneath London have resulted from failure to predict irregularities in the base of Quaternary deposits. Detailed knowledge of the three-dimensional shape of the Quaternary deposits can assist in predicting ground conditions. In order to provide such a model more than 22 000 borehole records from London have been encoded into a digital, relational database. Contour plots of specific geological surfaces, including the top of the Chalk, the base of the London Clay and the base of the Quaternary deposits have been generated from the database using computer-modelling software.
Quality assurance is an important part of the databasing procedure and suspect borehole information is discarded at an early stage. As computer modelling proceeds, further data may be eliminated if considered anomalous. The computing infrastructure provides graphical presentations of borehole logs, contour plots, isopachyte (thickness) plots of the major geological units together with cross-sections, fence diagrams, block diagrams and perspective views, giving an enhanced, three-dimensional understanding of the geology of London.
Subsidence hazard assessment as a basis for planning guidance in Ripon
Authors: Thompson Alan , Hine Peter , Peach Denis , Frost Lindsay , Brook David 
Published: April 2008

Abstract
The Ripon area of North Yorkshire provides a well-documented example of subsidence problems caused by the natural dissolution of gypsum deposits. This paper summarizes the findings of a programme of research, commissioned by the former Department of the Environment, which has aimed to assess the degree of hazard associated with this particular form of subsidence and to develop appropriate planning and engineering responses which might be applicable both to Ripon and to other affected areas. The paper draws attention to the sensitive nature of the problem and to the conflict which exists between the benefits of using hazard assessment to minimize the risk to future development within an area, and the possible disbenefits of widely publicizing the existence of a land instability problem.
In Ripon, the potential consequences of gypsum-related subsidence, in terms of building damage and road closures, can be significant. In addition, there may be a small risk of personal injury. It is therefore important that the planning of future development in the area should be guided by the results of the hazard assessment carried out in this study and that such development should be subject to controls and mitigation measures, where appropriate. However, the probability of this form of subsidence occurring at any given site is very low and the risk to individual properties is therefore generally very small, especially from the statistical viewpoint normally adopted by insurers. Taking account of these facts, forward planning and development control procedures have been recommended for use by the local planning authority.