The Landslide Handbook—A Guide to Understanding Landslides

U.S. Geological Survey Circular 1325

By:Lynn HighlandU.S. Geological Survey&Peter BobrowskyGeological Survey of Canada

Photo by Chua Chin Hon, Straits Times, Singapore – May 23, 2008, Epicentral area, Wenchuan Earthquake, Sichuan Province , China

Includes: New photos and information on the deadly Wenchuan Earthquake, Sichuan Province, China

Photo by Lynn HighlandU.S. Geological Survey

The Purpose of the Handbook :

To provide a basic, practical overview of landslide science with provisions and suggestions on reducing hazards from landslides

The Target Audience:*Decision-makes in the urban and rural communities around the world.

*Written at the level of a layperson’s understanding, initially in English

*Plan is to provide translations – French, Spanish, Mandarin and possibly, others.

The U.S. Geological Survey Landslide Information Center (NLIC , Lynn Highland, Coordinator )It will provide a resource center for those using the book who need help with its contents, and who would like more in-depth information.

The NLIC is accessible through a website, email, and toll-free telephone. http://landslides.usgs.gov

Country Languages Literacy Rate

Afghanistan Dali, Pashto 36 %

Algeria Arabic, Berber, French

70 %

Brazil Portuguese 88.6 %

Cameroon French 67.9 %

Canada, U.S. English, French, other

99 %

China Mandarin, others 90.9 %

Ethiopia Amharac 43 %

Guatemala Spanish 71.6 %

Honduras Spanish 76.2 %

India Hindi, English 61 %

Mexico Spanish 91 %

Namibia English 84 %

Nepal Nepali, 12 others 49 %

Peru Spanish, others 95% urban, 77 % rural

Philippines Tagalog, English 96 %

Senegal French, Wolof 40 %

(Source: US State Dept.)

Language Approximate # of speakers, worldwide

1. Chinese (Mandarin) 1,075,000,000

2. English 514,000,000

3. Hindustani1 496,000,000

4. Spanish 425,000,000

5. Russian 275,000,000

6. Arabic 256,000,000

7. Bengali 215,000,000

8. Portuguese 194,000,000

9. Malay-Indonesian 176,000,000

10.French 129,000,000

1Encompasses multiple dialects, including Hindi and Urdu.

Source: Ethnologue, 13th edition and other sources, 2007

2.

1.

3a.

3b.

Language Translation Goals

Reason for Book: There was found to be no comprehensive guide to basic landslideEducation that included sufficient illustrations or provided a user back-up/support approach

*No comprehensive, illustrated landslide handbook aimed at the developing world was found to be in print in English or other languages

*Exhaustive literature search to prevent duplication

of effort

Part I – Basic Information about landslides

Part II – Evaluating and Communicating Landslide Hazard

Part III – Mitigation concepts and approaches

Appendices

Appendix A - Basic Information About Landslides

Appendix B - Introduction to Mapping, Remote Sensing, and Monitoring of landslides

Appendix C– Introduction to landslide Stabilization and Mitigation Methods

Appendix D - Sample Safety Information for Landslides/Debris Flows – Suitable for Posting and/or Distributing

Types of landslides are presented and described, featuring a graphic representation and an actual photo

ROCKFALL

TOPPLE

DEBRIS FLOW

Leyte, Philippines

Photos and explanations For Rock fall Mitigation

Concrete Debris Flow CatchmentBasin (California, USA)

Debris-flow retaining wall (Japan)

Debris-flow MitigationTechniques

*Types of Maps – Susceptibility,

Geologic Etc.

*Monitoring & Instrumentation Examples

*Remote Sensing

Handbook Feataures Descriptions of Investigative Tools:

Examples of schematics of debris-flow mitigation for the homeowner

4. Landslide Dam mitigationThere are many problems encountered when landslides dam waterways. Dams caused by landslides are a common problem in many areas of the world. Landslides can occur on the valley walls of streams and rivers. If there is enough displaced material (rock, soil, and/or debris), to fill the waterway the landslide will act as a natural dam, blocking the flow of the river, creating flooding upstream. As these natural dams are composed of loose, unconsolidated, material they are often inherently weak and may soon be overtopped and will fail, due to erosion. When breaching happens quickly, the backed-up water, rushes down the waterway, causing potentially catastrophic downstream flooding. An example of, and one of the largest landslide dams in the world is the 600-meter-high Usoi landslide dam in Tajikistan. A large earthquake-induced landslide dammed the Murghab River, creating Lake Sarez. The situation is a hazard for people living downstream. Also, future seismic action may cause more landslides to slide into the dammed lake, causing a seiche, (a tsunami-like tidal wave in a lake), which may weaken and/or overtop the landslide dam.

Figure 42—Two photos of the Thistle landslide, Utah, USA. This 1983 landslide dammed the Spanish Fork River, backing up water that flooded the town of Thistle. Many landslide dams are much smaller than the one shown here, and can be potentially overtopped or eroded. Some are much larger, and damaged roads and railroad lines must be diverted around the landslide mass, as shown by tunnels at far left of photo on the right. This landslide is too large for removal and it has not overtopped or eroded. It still continues to move from time to time (Photos by Robert L. Schuster, U.S. Geological Survey).

See Appendix C for more details on mitigation methods for landslide dams.

Slope Stabilization using vegetation

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Example of Vetiver Grass as a soil stabilizer – can be grown throughout the world

Sample Safety information for landslides/debris flows suitable for posting and/or distributing.

Examples of Signage:

*What to do if you suspect imminent landslide danger

*What Can You Do If You Live Near Steep Hills?

*After landslides occur. . .

Basic Safety Information for Homeowners and Safety/Emergency

Managers

*What Can You Do If You Live Near Steep Hills?

Book is available for free from the U.S. GeologicalSurvey Publications Warehouse and is in downloadable form on the USGS website

http://www.usgs.gov

Thank you for your attention . . .

We welcome your opinions and comments!

------The Authors