The impact of hydrogeology on the instability of a road cutting through a drumlin in the North of Ireland

This paper describes the hydrogeological processes which caused unexpected instability and quick conditions during the excavation of a 25m deep cutting through a drumlin in County Down, Northern Ireland. A conceptual hydrogeological model of the cutting, based on pore pressures monitored during and after the excavation demonstrates how quick conditions at the toe of the cutting caused liquefaction of the till. Stability of the cutting was re-established by draining the highly permeable, weathered Greywacke which underlies the drumlin, through the use of a deep toe drain. In spite of this drainage, the cutting was only marginally stable due to the presence of a low permeability zone in the till above the bedrock which limits the reduction of elevated pore pressures within the upper to mid-depths of the drumlin. The factor of safety has been further improved by the addition of vertical relief drains at the crest and berm of the cutting to relieve the pore-pressures within the upper till by intercepting the weathered bedrock. The paper also highlights the importance of carrying out an adequate site investigation compliant with Eurocode 7 and additional monitoring in excavations in stiff, low permeability till.

Weighted Logratio Biplots, Correspondence Analysis and Spectral Maps

Starting with logratio biplots for compositional data, which are based on the principle of subcompositional coherence, and then adding weights, as in correspondence analysis, we rediscover Lewi's spectral map and many connections to analyses of two-way tables of non-negative data. Thanks to the weighting, the method also achieves the property of distributional equivalence

Using self organizing maps on compositional data

Self-organizing maps (Kohonen 1997) is a type of artificial neural network developed to explore patterns in high-dimensional multivariate data. The conventional version of the algorithm involves the use of Euclidean metric in the process of adaptation of the model vectors, thus rendering in theory a whole methodology incompatible with non-Euclidean geometries. In this contribution we explore the two main aspects of the problem: 1. Whether the conventional approach using Euclidean metric can shed valid results with compositional data. 2. If a modification of the conventional approach replacing vectorial sum and scalar multiplication by the canonical operators in the simplex (i.e. perturbation and powering) can converge to an adequate solution. Preliminary tests showed that both methodologies can be used on compositional data. However, the modified version of the algorithm performs poorer than the conventional version, in particular, when the data is pathological. Moreover, the conventional ap- proach converges faster to a solution, when data is \well-behaved". Key words: Self Organizing Map; Artificial Neural networks; Compositional data

PhotoLin: a program to identify and analyze linear structures in aerial photographs, satellite images and maps

A computer program, PhotoLin, written for an IBM-PC-compatible microcomputer is described which detects linear features in aerial photographs, satellite images and topographic maps. The program accepts images saved to PCX files as input and applies noise correction and smoothing filters and thinning routines. The output consists of a skeleton containing the median lines of linear features which can be represented on a map. The branches of the skeleton can be broken into sections of constant length for which the mean orientations are obtained for the preparation of rose diagrams. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Isopach Maps and Discussion of the Ordovician and Devonian of Montana and Adjacent Areas

The intensive postwar search for new petroleum horizons has resulted in widespread prospecting in the northern Great Plains. No commercial production has as yet been derived from Ordovician or Devonian rocks in Montana, but the relat­ively few tests that have penetrated to critical depths have disclosed encouraging conditions which merit further consider­ation, especially in Devonian strata.

Registration And Visualisation Of Deformation Maps From Terrestrial Radar Interferometry Using Photogrammetry And Structure From Motion

This paper describes a general workflow for the registration of terrestrial radar interferometric data with 3D point clouds derived from terrestrial photogrammetry and structure from motion. After the determination of intrinsic and extrinsic orientation parameters, data obtained by terrestrial radar interferometry were projected on point clouds and then on the initial photographs. Visualisation of slope deformation measurements on photographs provides an easily understandable and distributable information product, especially of inaccessible target areas such as steep rock walls or in rockfall run-out zones. The suitability and error propagation of the referencing steps and final visualisation of four approaches are compared: (a) the classic approach using a metric camera and stereo-image photogrammetry; (b) images acquired with a metric camera, automatically processed using structure from motion; (c) images acquired with a digital compact camera, processed with structure from motion; and (d) a markerless approach, using images acquired with a digital compact camera using structure from motion without artificial ground control points. The usability of the completely markerless approach for the visualisation of high-resolution radar interferometry assists the production of visualisation products for interpretation.

Hazard index maps for woody material recruitment and transport in alpine catchments

A robust and reliable risk assessment procedure for hydrologic hazards deserves particular attention to the role of transported woody material during flash floods or debris flows. At present, woody material transport phenomena are not systematically considered within the procedures for the elaboration of hazard maps. The consequence is a risk of losing prediction accuracy and of underestimating hazard impacts. Transported woody material frequently interferes with the sediment regulation capacity of open check dams and moreover, when obstruction phenomena at critical crosssections of the stream occur, inundations can be triggered. The paper presents a procedure for the determination of the relative propensity of mountain streams to the entrainment and delivery of recruited woody material on the basis of empirical indicators. The procedure provided the basis for the elaboration of a hazard index map for all torrent catchments of the Autonomous Province of Bolzano/Bozen. The plausibility of the results has been thoroughly checked by a backward oriented analysis on natural hazard events, documented since 1998 at the Department of Hydraulic Engineering of the aforementioned Alpine Province. The procedure provides hints for the consideration of the effects, induced by woody material transport, during the elaboration of hazard zone maps.

Cork, Ireland, 1771 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A survey of the city and suburbs of Cork, By J. Rocque, 1759. It was printed for Robert, Sayer, No. 53 in Fleet Street in 1771. Scale 1:2,400.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Irish Grid (Transverse Mercator 1965 (TM-65)) coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, built-up areas and selected buildings, ground cover, parks, gardens, docks, and more. Relief shown by shading.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

County Armàgh, Northern Ireland, United Kingdom, 1760 (Image 1 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A topographical map of the county of Armagh to which is anex'd the plans of Newry and Armagh, by John Rocque = Carte topographique de la Province d'Armagh où se trouve les plans des villes d'Armagh et de Newry, par Jean Rocque. It was published by J. Rocque in 1760. Scale [ca. 1:41,000]. This layer is image 1 of 4 total images of the four sheet source map, representing the southeast portion of the map. Covers County Armàgh, Northern Ireland. Map in English and French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Irish Grid (Transverse Mercator 1965 (TM-65)) coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, built-up areas and selected buildings, selected names of landowners, ground cover, and more. Relief shown by hachures and pictorially. Includes 2 insets: "A Plan of the Town of Newry" -- "A Plan of the City of Armagh".This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

County Armàgh, Northern Ireland, United Kingdom, 1760 (Image 2 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A topographical map of the county of Armagh to which is anex'd the plans of Newry and Armagh, by John Rocque = Carte topographique de la Province d'Armagh où se trouve les plans des villes d'Armagh et de Newry, par Jean Rocque. It was published by J. Rocque in 1760. Scale [ca. 1:41,000]. This layer is image 2 of 4 total images of the four sheet source map, representing the northeast portion of the map. Covers County Armàgh, Northern Ireland. Map in English and French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Irish Grid (Transverse Mercator 1965 (TM-65)) coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, built-up areas and selected buildings, selected names of landowners, ground cover, and more. Relief shown by hachures and pictorially. Includes 2 insets: "A Plan of the Town of Newry" -- "A Plan of the City of Armagh".This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

County Armàgh, Northern Ireland, United Kingdom, 1760 (Image 3 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A topographical map of the county of Armagh to which is anex'd the plans of Newry and Armagh, by John Rocque = Carte topographique de la Province d'Armagh où se trouve les plans des villes d'Armagh et de Newry, par Jean Rocque. It was published by J. Rocque in 1760. Scale [ca. 1:41,000]. This layer is image 3 of 4 total images of the four sheet source map, representing the southwest portion of the map. Covers County Armàgh, Northern Ireland. Map in English and French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Irish Grid (Transverse Mercator 1965 (TM-65)) coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, built-up areas and selected buildings, selected names of landowners, ground cover, and more. Relief shown by hachures and pictorially. Includes 2 insets: "A Plan of the Town of Newry" -- "A Plan of the City of Armagh".This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.