SCOTTISH ROAD NETWORK LANDSLIDES STUDY

DescriptionThis report explains what landslides are, how they can be assessed in terms of the hazards they create and the exposure to road users, identifies areas of high hazard that currently exist in scotland and makes recommendations as to how the future detailed assessment of the scottish road network could be undertaken and the management approaches which could be adopted to mitigate the effects.
ISBN
Official Print Publication Date
Website Publication DateJuly 12, 2005

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Editors: M G Winter ( TRL Limited), F Macgregor and L Shackman (Scottish Executive)
ISBN 0 7559 4649 9

This document is also available in pdf format: part 1 (1.1mb), part 2 (1.8mb)

Contents

FOREWORD
WORKING GROUP MEMBERS AND REPORT CONTRIBUTORS
EXECUTIVE OVERVIEW
1 INTRODUCTION TO LANDSLIDE HAZARDS
2 BACKGROUND TO SCOTTISH LANDSLIDES AND DEBRIS FLOWS
2.1 Landslides
2.2 Recent Debris Flows
2.3 Climatic Issues
2.4 Current Inspection and Maintenance Arrangements
2.5 Potential Third Party Issues
3 DEBRIS FLOW INFORMATION SOURCES
3.1 Key Findings from the Literature
3.2 The Project Workshop
3.3 Potential Third Party Issues
4 DEBRIS FLOW TYPES AND MECHANISMS
4.1 Flows
4.2 Debris Flows
4.3 Principles of Rapid Landslide Development
5 KEY CONTRIBUTORY FACTORS TO DEBRIS FLOWS
5.1 Hazard Factors Affecting Debris Flow Occurrence
5.2 Hazard Factors Affecting Debris Flow Run-Out
5.3 Factors Affecting Exposure to Debris Flow Hazards
5.4 Summary of Key Contributory Factors
6 PROPOSED METHODOLOGY FOR DEBRIS FLOW ASSESSMENT
6.1 Hazard Assessment
6.2 Hazard Ranking
6.3 Detailed Assessment Factors
7 HIGH HAZARD AREAS AND EARLY OPPORTUNITIES IN SCOTLAND
7.1 Areas of High Perceived Hazard
7.2 Early Opportunities
8 DEBRIS FLOW MANAGEMENT AND MITIGATION OPTIONS
8.1 Managing the Asset
8.2 Approaches to Landslide Management
8.3 Asset Management for Trunk Road Slopes
8.4 Mitigation Techniques
9 SUMMARY AND RECOMMENDATIONS FOR DEBRIS FLOWS IN SCOTLAND
9.1 Summary
9.2 Recommendations
REFERENCES
APPENDIX - PROJECT WORKSHOP AGENDA

Cover photo - The A85 in Glen Ogle blocked by two debris flows

Cover Photograph (© Perthshire Picture Agency, PPA: www.ppapix.co.uk ):The A85 in Glen Ogle blocked by two debris flows on 18 August 2004. RAF and Royal Navyhelicopters are pictured airlifting some of the 57 occupants from the 20 trapped vehicles tosafety.

Electronic copies of this report may be obtained from the Scottish Executive web site (www.scotland.gov.uk).

The views expressed in this report are those of the Editors and Authors and do not necessarily represent those of the Department or Scottish Ministers.

The Scottish Executive and Astron would like to point out that some of the images in this document are of a poorer quality than would normally appear in their documents. This is because some photographs were taken on digital cameras, mobile phone cameras and/or in difficult conditions. In addition, some of the graphs and images used have been necessarily downloaded from websites at low resolutions which are of a poor reproductive quality when printed.

© Crown Copyright 2005. Except as otherwise stated.Limited extracts from the text may be reproduced provided the source is acknowledged. For more extensive reproduction, please write to theChief Road Engineer, Scottish Executive, Victoria Quay, Edinburgh,EH6 6QQ.