Terrain Hazard Research Articles

Natural Terrain – a Constraint to Development? Proceedings of the 14 November 2002 conference organised by the Hong Kong Branch of the Institution of Mining and Metallurgy, 237 pages, HK$ 300, published by IMM, Hong Kong 2002

These proceedings contain 18 separate articles, including keynote submissions (Earl Brabb et al. ; Oldrich Hungr) and an invited paper (Gareth Hearn). It should be noted that the title of the book is somewhat misleading, as this is primarily a collection of papers on landslides, albeit within the context of natural terrain hazards, and mainly concentrates on landslides in Hong Kong. However, the book is a delight to read, as the quality of the material (if not all the illustrations) is extremely high and the editors should be …

New Traversability Indices and Traversability Grid for Integrated Sensor/Map‐Based Navigation

AbstractThis paper presents new measures of terrain traversability at short range and long range of a mobile robot; namely, local and global traversability indices. The sensor‐based local traversability index is related by a set of linguistic rules to large obstacles and surface softness within a short range of the robot measured by on‐board sensors. The map‐based global traversability index is obtained from the terrain topographic map, and is based on major surface features such as hills and lakes within a long range of the robot. These traversability indices complement the mid‐range sensor‐based regional traversability index introduced earlier. Each traversability index is represented by four fuzzy sets with the linguistic labels {POOR, LOW, MODERATE, HIGH}, corresponding to surfaces that are unsafe, moderately‐unsafe, moderately‐safe, and safe for traversal, respectively. The global terrain analysis also leads to the new concepts of traversability map and traversability grid for representation of terrain quality based on the global map information. The traversability indices are used in two sensor‐based traverse‐local and traverse‐regional behaviors and one map‐based traverse‐global behavior. These behaviors are integrated with a map‐based seek‐goal behavior to ensure that the mobile robot reaches its goal safely while avoiding both sensed and mapped terrain hazards. This provides a unified system in which the two independent sources of terrain quality information, i.e., prior maps and on‐board sensors, are integrated together for reactive robot navigation. The paper is concluded by a graphical simulation study. © 2003 Wiley Periodicals, Inc.

FIDO prototype Mars rover field trials, Black Rock Summit, Nevada, as test of the ability of robotic mobility systems to conduct field science

The Field Integration Design and Operations (FIDO) prototype Mars rover was deployed and operated remotely for 2 weeks in May 2000 in the Black Rock Summit area of Nevada. The blind science operation trials were designed to evaluate the extent to which FIDO‐class rovers can be used to conduct traverse science and collect samples. FIDO‐based instruments included stereo cameras for navigation and imaging, an infrared point spectrometer, a color microscopic imager for characterization of rocks and soils, and a rock drill for core acquisition. Body‐mounted “belly” cameras aided drill deployment, and front and rear hazard cameras enabled terrain hazard avoidance. Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) data, a high spatial resolution IKONOS orbital image, and a suite of descent images were used to provide regional‐ and local‐scale terrain and rock type information, from which hypotheses were developed for testing during operations. The rover visited three sites, traversed 30 m, and acquired 1.3 gigabytes of data. The relatively small traverse distance resulted from a geologically rich site in which materials identified on a regional scale from remote‐sensing data could be identified on a local scale using rover‐based data. Results demonstrate the synergy of mapping terrain from orbit and during descent using imaging and spectroscopy, followed by a rover mission to test inferences and to make discoveries that can be accomplished only with surface mobility systems.

Terrain hazard around the Ok Tedi copper mine, Papua New Guinea

Rationale Located in the remote Star Mountains of Western Province, Papua New Guinea, the Ok Tedi open-cut copper mine operates under conditions of particular topographical and geotechnical adversity. Slopes are frequently steep, rocks are highly fractured and weakened due to tectonics and weathering, and rainfall is world record-breaking, with annual totals exceeding 10 m in the vicinity of the mine (Jones & Maconochie 1990). The mine is planned to occupy an area of 2 km diameter with a depth of 500 m at an altitude of 1800 m a.s.l. The mine supply corridor, along which power, food and other essential materials are brought in and copper concentrate is piped out, is 160 km long, and is itself at risk from slope, flooding and erosional hazards. The threat posed by these hazards to the operation of the mine and the viability of its supply corridor has been recognized and evaluated by the geotechnical department of Ok Tedi Mining Ltd (OTML) since the project‘s inception. However, the severity and proximity of this risk were perhaps not fully realized until 1989 when a rock avalanche involving perhaps as much as 70 x 10 6 m 3 of material occurred within a very short distance of the mine office. The collapse of the mountainside was dramatic and was considered to have been responsible for the seismic event recorded at the time of failure in Port Moresby, approximately 800 km away. Although the infrastructure of the mine was not directly affected by this failure, it served as a

Were The Lollards a Sect?

Historians should not need Wyclif to alert them to the dangers of words. Even if our professional futures are unlikely to be threatened, as his was, by the challenging of accepted terms, the words we use can lead us into false positions, and we sometimes need, like Wyclif, to probe the historical dimension of our terminology. What exactly do we mean when we call Wycliffites or Lollards a ‘sect’? How does our word relate to contemporary usage? Do we import alien interpretations by failure to recognize semantic change? If ‘sect’ is a word that leads us into something of an impasse, this paper does not attempt the impossible of pointing to a way out; my aim is merely to indicate some of the hazards of the linguistic terrain and to suggest that looking at the term may itself tell us something useful about Wycliffites and contemporary attitudes towards them.

Three-Dimensional Displays for Terrain and Weather Awareness in the National Airspace System

Three experiments are reported in which participants (air traffic controllers, Experiments 1 and 2; pilots, Experiment 3) were required to guide an aircraft around the hazards of terrain (Experiment 1) and weather (Experiments 2 and 3), using either 2D (planar) or 3D (perspective) displays. In Experiment 2, air traffic controllers, but not pilots, were less accurate in projecting tracks around terrain with the 3D display than with the 2D display. In Experiment 2, there was little difference between display formats in their ability to support safe vectoring around weather. In Experiment 3, pilots took slightly longer to plan a route around weather with the 3D display, and did so with equivalent accuracy to the 2D display. In all three experiments, the 3D display supported creation of paths that were slightly longer, and skirted the hazard by a wider margin than did the 2D display.

Landslide and erosion hazard mapping at Ok Tedi copper mine, Papua New Guinea

Abstract Landslides and erosion pose significant hazards to mining and engineering activity in the remote mountainous terrain of Western Province, Papua New Guinea. The investigation and containment of these hazards have been the concern of the Ok Tedi open-cast copper mine since engineering feasibility studies began in 1978. Subsequent terrain hazard mapping has identified numerous landslides and rock avalanche deposits in the Ok Tedi catchment and in the immediate vicinity of the mine, ranging from very low frequency, catastrophic rock avalanches through to mudslides and mudflows that recur on a daily or weekly basis. This mapping formed part of a multidisciplinary geotechnical study instigated by Ok Tedi Mining Limited and comprised detailed slope inventory, geomorphological mapping combined with air photograph interpretation nd a review of pre-existing structural geological and geotechnical data. The study area was sub-divided into 245 zones and assigned hazard and risk categories or levels derived from the field data. These classifications were presented in map form at 1:10 000 scale along with prioritized recommendations for further investigation, monitoring and remedial action, where appropriate.

An Interpretation of the Philippine Election of 1953

Conditions for the successful operation of the democratic form of government have not been present in the Orient. Democracy requires a people who have confidence in themselves, in their leaders, and in the democratic processes, and who have the means for operating democratic institutions. Included in the tools that make democracy work are literacy, a willingness to abide by the rules of the game, and a rapid means of communication and transportation. In the Orient a fatalistic view regarding government is widespread. People in the lower income groups feel that government is an institution of the few, by the few, and for the few. Vote buying, spoils politics, favoritism, nepotism, grafting, the squeeze, the hold up, the percentage are all taken for granted. As one Filipino senator put it, “Graft and corruption are inherent in human nature.” The Orient also suffers from the primitive character of means of transportation and communications. Roads are bad, newspapers have limited circulations, telephones and telegraph stations are few, radios are scarce, and travel is often complicated by hazards of water, mountainous terrain, bandits, and wild animals.The Philippine elections of November 10, 1953 show that the difficulties that have hindered the growth of democracy in the Orient can be overcome. Before the elections apprehension was widespread that extensive use might be made of fraud and terror to defeat the free expression of the popular will.