Usgs - National Landslide Hazards Mitigation Strategy

8/3/2019 Usgs - National Landslide Hazards Mitigation Strategy

1/64

National Landslide Hazards

M itigation StrategyA Framew ork for Loss Reduction

Circular 1244

U.S. Department of the Interior

U.S. Geological Survey


2/64

Landslide overview map of the conterminous United States. Different c olors denote areas of varying landslide occurrence. From

U.S. Geologic al Survey, 1997, Digital c ompilation of landslide over view map of the c onterminous United States: U.S. Geologic al

Survey Open-File Report 970289, digital c ompilation by Jonathan W. Godt, available on the w eb at

http://greenwood.cr.usgs.gov/pub/open-file-reports/ofr-97-0289/.

Front cover. Massive landslide at La Conchita, California, a small seaside community along Highway 101 north of Santa Barbara.This landslide and debris flow occurr ed in the spring of 1995. Many people w ere evacuated because of t he slide, and the housesnearest the slide were completely destroyed. Fortunately, no one was killed or injured. Photograph by R.L. Schuster, U.S.Geological Survey.


3/64



By Elliott C. Spiker and Paula L. Gori

Circular 1244

U.S. Department of the InteriorU.S. Geologica l Survey


4/64

U.S. Department of the InteriorGale A. Norton, Secretary

U.S. Geological SurveyCharles G. Groat, Director

U.S. Geological Survey, Reston, Virginia: 2003

Free on application toU.S. Geological SurveyInformation ServicesBox 25286, Federal CenterDenver, CO 80225

For more information about the USGS and its product s:Telephone: 1888ASKUSGSWorld Wide Web: http://www .usgs.gov

Any use of trade, product, or firm names in this publication is fordescriptive purposes only and does not imply endorsement bythe U.S. Government.

Library of Congress Cataloging i n Publica tions Data

Spiker, Elliot t C.

National landslide hazards mitigation strategy : a fr amework for loss reduction / byElliott C. Spiker and Paula Gori.

p. cm.-- (Circ ular ; 1244)

Includes bibliographical references.

1. Landslide hazard analysis--United States. I. Gori, Paula. II. Title. III . U.S.

Geological Survey circular ; 1244.

QE599.U5S65 2003.

363.349--dc21 2002044779


5/64

Preface

House Report 106222 accompanying the Interior Appropriations Bill for f iscalyear 2000 (as incorporated in Public Law 106113) states, "The committee isconcerned over the lack of attention given to the Surveys landslide program.Because of t his concern, the Survey is directed to develop by September 15,2000, a comprehensive strategy, including the estimated costs associated withaddressing the w idespread landslide hazards facing the Nation. The preparationof this strategy should include the involvement of all parties having responsibili-ty for dealing wi th t he problems associated wi th landslides."

In fulfillment of the requirements of Public Law 106113, the United States Geo-logical Survey submits this circular, which describes a national strategy to

reduce losses from landslides. The circular includes a summary of t he Nat ionsneeds for research, monitoring, mapping, and assessment of landslide hazardsnationwide.

ii i


6/64

v

Contents

Prefac e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii i

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Losses from Landslide Hazards in the United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7A National Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

The Nat ional Landslide Hazard M itigation Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Reaching the Goal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Major Elements and Strategic Object ives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Element 1. Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Element 2. Hazard Mapping and Assessments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Element 3. Real-Time M onitor ing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Element 4. Loss Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Element 5. Informat ion Collection, Interpretation, Dissemination, and Archiving . . . . 20Element 6. Guidelines and Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Element 7. Public Aw areness and Education . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Element 8. Implementation of Loss Reduction Measures . . . . . . . . . . . . . . . . . . . . . . . 24Element 9. Emergency Preparedness, Response, and Recovery . . . . . . . . . . . . . . . . . 26

Act ion Items for a National Strategy for Reducing Losses from Landslides . . . . . . . . . . . . . . . . 28Key Steps for Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Management Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28New and Enhanced Roles and Partnerships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Funding for the USGS to Implement a National Strategy for Reducing Losses

from Landslides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Expansion of the Work Performed by Scientists in the Landslide Hazards Program . . . 31Establishment of a New Cooperative Landslide Hazard Assessment and

Mapping Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Establishment of a New Cooperative Federal Land Management

Landsl ide Hazards Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Establishment of New Partnerships for Landslide Hazard Loss

Reduction Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Funding Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Major Accomplishments and Produc ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Appendix 1. Previous Reports and Sources of Landslide Hazards Informat ion . . . . . . . . . . . . . 35Appendix 2. Meetings w ith Stakeholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Appendix 3. Landslide Hazards and Other Ground Failures Causes and Types . . . . . . . . . . . . 39Appendix 4. Landslide Hazards M itigation Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Appendix 5. Landslide Hazards M aps and Risk Assessments . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Appendix 6. Current Landslide Research and Mitigation Activities and Responsibilities

in the Uni ted States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Appendix 7. Federal Agency Landslide Hazard Ac tivi ties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48


7/64

vi

Highlights

1. Massive Landslide at Thistle, Utah . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2. Wildf ires and Debris Flow s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83. Building Disaster-Resistant Communities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104. Debris-Flow Flume Understanding Landslide Proc esses . . . . . . . . . . . . . . . . . . . . . . . . . . . 125. Mapping Debr is-Flow Hazards in M adison County, Virginia . . . . . . . . . . . . . . . . . . . . . . . . . . 156. Real-Time M onitoring of Active Landslides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177. Inventory of Slope Failures in Oregon for Three 199697 Storm Events . . . . . . . . . . . . . . . . 198. Warning of Potential Landslides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219. Alert ing the Public to the Hazards of M ount Rainier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

10. Cinc innat i, Ohio A Leader in Landslide Loss Reduction M easures . . . . . . . . . . . . . . . . . . . 2511. Daly City The Human Cost of Landsl ides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figures14. Photographs show ing

1. Massive landslide at Thistle, Utah, 1983 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52. Debris f low near Glenwood Springs, Colorado, 1994 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83. Landsl ide in nor thw est Seat tle, Washington . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104. Debris-flow flume, 45 miles east of Eugene, Oregon, constructed to conduct

controlled exper iments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125. Portion of debr is-flow hazard map, M adison County, Virg inia . . . . . . . . . . . . . . . . . . . . . . . 156. Diagram showing netw ork for transmission of real- time landslide data . . . . . . . . . . . . . . . 177. Photograph show ing sc ient ist measuring landslide movement . . . . . . . . . . . . . . . . . . . . . . 178. Photograph showing scientists testing a solar-powered radio telemetry system for

remote transmission of real-time landslide data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

9. Landsl ide- inventory map for three 199697 storm events in Oregon . . . . . . . . . . . . . . . . . . 1910. Photographs showing debris flow in Pacifica, California, and house (inset) at

edge of debr is f low , 1982 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2111. Map showing hazard zones from lahars, lava flows, and pyroclastic flows

from M ount Rainier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2312. Photograph show ing ear thf low in Cincinnat i, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2513. Photograph showing gully retreat threatening evacuated houses in

Daly City, Cali fornia, 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2751. Maps of part of Seattle, Washington, showing (A) landslide inventory, (B) landslide

susceptibility, (C), Probability of landslide occurrence, (D) Probability of landslidedamage, and (E) Risk of loss due to landsl ides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Table

1. New roles and partnership opportunities under the National Landslide HazardsM it igation Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29


8/64

This circular outlines the key elements of a comprehensive and effectivenational strategy for reducing losses from landslides nationwide and providesan assessment of the status, needs, and associated costs of this strategy. The cir-cular is submitted in compliance with a directive of Public Law 106113 (seepreface). A broad spectrum of expert opinion was sought in developing thisstrategy report, as requested by the U.S. Congress in House Report 106222.

The strategy was developed in response to the rising costs resulting fromlandslide hazards in the United States and includes activities at the National,

State, and local levels, in both the public and private sectors. The strategygives the Federal Government a prominent role in efforts to reduce losses dueto landslide hazards, in partnership with State and local governments. TheU.S. Geological Survey (USGS) has taken the lead in developing the strategyon behalf of the large multisector, multiagency stakeholder group involved inlandslide hazards mitigation. The USGS derives its leadership role in landslidehazard-related work from the Disaster Relief Act of 1974 (Stafford Act). Forexample, the Director of the USGS has been delegated the responsibility toissue disaster warnings for an earthquake, volcanic eruption, landslide, orother geologic catastrophe (1974 Disaster Relief Act 42 U.S.C. 5201 et seq).

The National Landslide Hazards Mitigation Strategy includes developing

new partnerships among government at all levels, academia, and the privatesector and expanding landslide research, mapping, assessment, real-time mon-itoring, forecasting, information management and dissemination, mitigationtools, and emergency preparedness and response. Such a strategy uses newtechnological advances, enlists the expertise associated with other related haz-ards such as floods, earthquakes and volcanic activity, and utilizes incentivesfor the adoption of loss reduction measures nationwide.

Executive Summary

1



By Elliott C. Spiker and Paula L. Gori

"Science by itself w ill not protect us. Federal, State, and local governments, the private sector, volunteerand charitable organizations and individual citizens must w ork together in applying the science to makeour communities safer."

Charles Groat, Director of the U.S. Geological Survey


9/64

The strategy envisions a society that is fully aware of landslide hazardsand routinely takes action to reduce both the risks and costs associated withthose hazards. The long-term mission of a comprehensive landslide hazardmitigation strategy is to provide and encourage the use of scientific informa-tion, maps, methodology, and guidance for emergency management, land-use

planning, and development and implementation of public and private policyto reduce losses from landslides and other ground-failure hazards nationwide.The 10-year goal is to substantially reduce the risk of loss of life, injuries,economic costs, and destruction of natural and cultural resources that resultfrom landslides and other ground-failure hazards.

This comprehensive National Landslide Hazards Mitigation Strategyemploys a wide range of scientific, planning, and policy tools to address var-ious aspects of the problem to effectively reduce losses from landslides andother ground failures. It has the following nine major elements, spanning acontinuum from research to the formulation and implementation of policyand mitigation:

Research.Developing a predictive understanding of landslideprocesses and triggering mechanism

Hazard mapping and assessments.Delineating susceptible areas anddifferent types of landslide hazards at a scale useful for planning anddecisionmaking

Real-time monitoring.Monitoring active landslides that pose sub-stantial risk

Loss assessment.Compiling and evaluating information on the eco-nomic impacts of landslide hazards

Information collection, interpretation, and dissemination.

Establishing an effective system for information transfer Guidelines and training.Developing guidelines and training for sci-

entists, engineers, and decisionmakers Public awareness and education.Developing information and educa-

tion for the user community Implementation of loss reduction measures.Encouraging mitigation

action Emergency preparedness, response, and recovery.Building resilient

communities

In each of the above nine elements above, the USGS has a significant role;

however, the USGS is not the lead for all elements.

2


10/64

Landslide hazards mitigation requires collaboration among academia, gov-ernment, and the private sector. Aggressive implementation of a comprehen-sive and effective national landslide hazards mitigation strategy requiresincreased investment in landslide hazard research, mapping and monitoring,and mitigation activities. Reducing losses from landslide hazards can be

accomplished in part by expanding the existing USGS Landslide HazardProgram, as follows:

Expansion of research, assessment, monitoring, public information,and response efforts by USGS scientists ($8 million annually)

Establishment of a Cooperative Landslide Hazard Assessment andMapping Program to increase the efforts of State and local govern-ments to map and assess landslide hazards within their jurisdictionsthrough competitive grants ($8 million annually, to be augmentedwith 30 percent matching funds by the States and local jurisdictions)

Establishment of a Cooperative Federal Land Management Landslide

Hazard Program to increase the capability of the National ParkService, U.S. Forest Service, Bureau of Land Management, andother such organizations to address landslide hazards under theirjurisdictions ($2 million annually for work performed by USGS sci-entists on public lands)

Establishment of a Partnerships for Landslide Hazard Loss ReductionProgram to support research and implementation efforts by universi-ties, local governments, and the private sector through competitivegrants ($2 million annually)

Total new funding required for full implementation of the National Landslide

Hazards Mitigation Strategy within the USGS is estimated to be approximate-ly $20 million annually.

An effective National Landslide Hazards Mitigation Strategy also dependson stronger partnerships among Federal, State, and local governments and theprivate sector in the areas of hazard assessments, monitoring, and emergencyresponse and recovery. The strategy recommended in this circular advocatesenhanced coordination among Federal, State, and local agencies to partnereffectively with the academic and the private sectors and to leverage sharedresources under the leadership of the USGS.

3


11/64

Landslides and other forms of ground failure affect communities all acrossthe Nation. Despite advances in science and technology, these events continueto result in human suffering, billions of dollars in property losses, and environ-mental degradation. As our population increases and our society becomes evermore complex, the economic and societal costs of landslides and other ground

failures will continue to rise.We have the capability as a Nation to understand and identify these haz-ards and to implement mitigation measures. For many years, the U.S.Geological Survey (USGS), the States, numerous universities, and the privatesector have been grappling with understanding and reducing landslide hazards,and they have developed an extensive body of knowledge (see appendix 1 forsources of information). However, to achieve the goal of significantly reducinglosses from landslide hazards, we need a much more comprehensive scientificunderstanding of landslide processes and occurrence, a robust monitoring pro-gram to warn of impending danger from active landslides, a much greater pub-lic awareness and understanding of the threat and the options for reducing the

risk, and action at the local level.A significant, sustained, long-term effort to reduce losses from landslidesand other ground failures in the United States will require a national commit-ment among all levels of government and the private sector. The FederalGovernment, in partnership with State and local governments, must provideleadership, coordination, research support, incentives, and resources to encour-age communities, businesses, and individuals to undertake mitigation to mini-mize potential losses and to employ mitigation in the recovery following land-slides and other natural hazard events.

The USGS is the recognized authority for understanding landslide hazardsin the United States and the long-time leader in this area. The USGS derives

its leadership role in landslide-hazard-related work from the Disaster ReliefAct of 1974 (Stafford Act). The Director of the USGS has been delegated theresponsibility to issue disaster warnings for an earthquake, volcanic eruption,landslide, or other geologic catastrophe consistent with the 1974 DisasterRelief Act 42 U.S.C. 5201 et seq.

As requested by the U.S. Congress in House Report 106222, the USGShas prepared this National Landslide Hazards Mitigation Strategy on behalf ofthe large multisector, multiagency stakeholder group involved in landslideresearch and mitigation nationwide. A number of stakeholder workshops wereheld during 1999 and 2000 with representatives of government and privateorganizations, academicians, and private citizens to seek their opinion and

input (see appendix 2 for more information about the stakeholder workshops).

Introduction

4


12/64

The 1983 Thistle landslide beganmoving in the spring of 1983 inresponse to ground-water buildupfrom heavy rains the previousSeptember and melting snowpackfrom the winter of 1983. Within a few

weeks, the landslide dammed theSpanish Fork River, consequentlyobliterating U.S. Highway 6 and themain line of the Denver and RioGrande Western Railroad (fig. 1).

The town of Thistle w as inundat-ed by the floodwaters rising behindthe landslide dam. Eventually a drainsystem was engineered to drain the

lake and avert a potential disaster.The landslide reached a state of equi-librium across the valley, but fears ofreactivation caused the railway toconstruct a tunnel through bedrockaround the slide zone at a cost of mil-

lions of dollars. The highway likew isewas realigned around the landslide.When the lake w as drained, residualmuck partially buried the town, and vir-tually no one returned to Thistle. Totalcosts (direct and indirect) incurred bythis landslide exceeded $400 million,making this the most costly singlelandslide event in U.S. history.

Figure 1. The 1983 Thistle landslide,

central Utah. Thistle Lake, which

resulted from damming of the Spanish

Fork River, was later drained as a pre-cautionary measure. This view, taken

about 6 months after the slide

occurred, shows the r ealignment of the

Denver and Rio Grande Western

Railroad lines in the lower center and

the large cut for rerouting U.S.

Highway 6/50 on the extreme left sideof the photograph.

Photograph by R.L. Schuster, U.S.

Geological Survey.

Highlight 1M assive Landslide atThistle, Utah

5


13/64

The National Landslide Hazards Mitigation Strategy provides a frame-work for reducing losses from landslides and other ground failures.Although the strategy is national in scope, it is not exclusively Federal oreven exclusively governmental. Mitigation, defined as any sustainedaction taken to reduce and eliminate long-term risk to life and property,

generally occurs at the State and local levels, and the strategy is based onpartnerships with stakeholders at all levels of government and in theprivate sector.

The National Landslide Hazards Mitigation Strategy described hereincorporates many ideas and recommendations of previous studies andreports that expressed the need for a national strategy to address naturalhazards, including landslides and other ground failures (see appendix 1).These earlier studies and reports should be referred to for more in-depthdiscussions of and insights into landslide hazard mitigation and researchneeds. The National Landslide Hazards Mitigation Strategy builds on theprinciples, goals, and objectives of the National Mitigation Strategy

Partnerships for Building Safer Communities, developed in 1996 by theFederal Emergency Management Agency (FEMA) to encourage mitigationof all forms of natural hazards in the United States.

The term "landslide" describes many types of downhill earth move-ments, ranging from rapidly moving catastrophic rock avalanches anddebris flows in mountainous regions to more slowly moving earth slidesand other ground failures. In addition to the different types of landslides,the broader scope of ground failure includes subsidence, permafrost, andshrinking soils. This report focuses on landslides, the most critical ground-failure problem facing most regions of the Nation. However, the NationalLandslide Hazards Mitigation Strategy provides a framework that can be

applied to other ground-failure hazards (see appendix 3 for more informa-tion about different types of landslide hazards and other forms of groundfailure).

6


14/64

Landslides are among the most widespread geologic hazards on Earth.Landslides cause billions of dollars in damages and thousands of deaths andinjuries each year around the world. Landslides threaten lives and property inevery State in the Nation, resulting in an estimated 25 to 50 deaths and dam-age exceeding $2 billion annually. Although most landslides in the United

States occur as separate, widely distributed events, thousands of landslides canbe triggered by a single severe storm and earthquake, causing spectaculardamage in a short time over a wide area.

The United States has experienced several catastrophic landslide disastersin recent years. In 1985, a massive slide in southern Puerto Rico killed 129people, the greatest loss of life from a single landslide in U.S. history. The198283 and 198384 El Nio seasons triggered landslide events that affectedthe entire Western United States, including California, Washington, Utah,Nevada, and Idaho. The Thistle, Utah, landslide of 1983 caused $400 millionin losses, the most expensive single landslide in U.S. history, and the 199798El Nio rainstorms in the San Francisco Bay area produced thousands of land-

slides, causing over $150 million in direct public and private costs.Landslides are a significant component of many major natural disastersand are responsible for greater losses than is generally recognized. Landslidedamage is often reported as a result of a triggering eventfloods, earthquakes,or volcanic eruptionseven though the losses from landsliding may exceed allother losses from the overall disaster. For example, flash floods in mountain-ous areas often have devastating debris flows. Also, most of the losses due tothe 1964 Alaska earthquake resulted from ground failure rather than fromshaking of structures, and landslides associated with a major earthquake inAfghanistan and with Hurricane Mitch in Central America in 1998 caused themajority of fatalities in these disasters.

All 50 States and the U.S. Territories experience landslides and otherground-failure problems; 36 States have moderate to highly severe landslidehazards. The greatest landslide damage occurs in the Appalachian, RockyMountain, and Pacific Coast regions and Puerto Rico. Seismically activemountainous regions, such as those in Alaska, Hawaii, and the West Coast areespecially at risk. Extremely vulnerable are areas where wildfires havedestroyed vegetation, exposing barren ground to heavy rainfall.

Landslide losses are increasing in the United States and worldwide asdevelopment expands under pressures of increasing populations. The resultingencroachment of developments into hazardous areas, expansion of transporta-tion infrastructure, deforestation of landslide-prone areas, and changing cli-

mate patterns may lead to continually increasing landslide losses. However, anincrease in the cost of landslide hazards can be curbed through better under-standing and mapping of the hazards and improved capabilities to mitigate andrespond to the hazards.

Losses from Landslide

Hazards in the United

States

7


15/64

Colorado River (fig. 2). A 3-mile lengthof the highway w as buried under tonsof rock, mud, and burned trees. Theclosure of Interstate 70 imposed cost-ly delays on this major transcontinen-tal highw ay. The USGS assisted in

analyzing the debris-flow threat andinstalling monitoring and warning sys-tems to alert local safety officialswhen high-intensity rainfall occurredor debris flow s passed through a sus-ceptible canyon. Similar debris flow sthreaten other transportation corri-dors and other development in andnear fire-ravaged hillsides.

FromHighland, L.M., Ellen, S.D.,Christi an, S.B., and Brow n, W.M., III,1997, Debris-flow hazards in theUnited States: U.S. Geological Survey

Fact Sheet FS17697, available onthe web athttp://geohazards.cr.usgs.gov/factsheets/debrisflowfs.pdf.

During the summer of 2000,numerous w ildfires burned drought-parched areas of the Western UnitedStates. U.S. Geological Survey (USGS)scientists were enlisted to adviseFederal and State emergency

response teams on the potential forfuture debris flows in burned areas,such as the Cerro Grande fire (LosAlamos, New Mexico) and the Hi-Meadow and Bobcat fires (Colorado).

Debris flow s often occur duringthe fall and winter follow ing majorsummer fires. One such combinationof fires and debris flows occ urred inJuly 1994, when a severe wildfireswept Storm King Mountain west ofGlenwood Springs, Colorado, denud-ing the slopes of vegetation. Heavy

rains on the mountain the followingSeptember caused numerous debrisflows, one of which blocked Interstate70 and threatened to dam the

Highlight 2Wildfires and Debris Flow s

8

Figure 2. Debris flows like this one near

Glenw ood Spri ngs, Colorado, in 1994

are a consequence of heavy rainfall on

previously burned hillsides. In addition

to personal injuries and damage to 30

vehicles engulfed by these flows, tr ans-

portation along the Interstate 70 corri-dor w as brought to a standstill for a day,

and business and emergency opera-

tions in the Glenwood Springs area

were seriously impeded. Photograph by

Jim Scheidt , U.S. Bureau of Land

Management.


16/64

Landslides and other ground failures impose many direct and indirectcosts on society. Direct costs include the actual damage sustained by buildingsand property, ranging from the expense of cleanup and repair to replacement.Indirect costs are harder to measure and include business disruption, loss oftax revenues, reduced property values, loss of productivity, losses in tourism,

and losses from litigation. The indirect costs often exceed the direct costs.Much of the economic loss is borne by Federal, State, and local agencies thatare responsible for disaster assistance and highway maintenance and repair.

Landslides have a significant adverse effect on infrastructure and threatentransportation corridors, fuel and energy conduits, and communications link-ages. Ground-failure events have devastating economic effects on Federal,State, local, and private roads, bridges, and tunnels every year. Railroads,pipelines, electric and telecommunication lines, dams, offshore oil and gasproduction facilities, port facilities, and waste repositories continually areaffected by land movement. Road building and construction often exacerbatethe landslide problem in hilly areas by altering the landscape, slopes, and

drainages and by changing and channeling runoff, thereby increasing thepotential for landslides. Landslides and others forms of ground failure alsohave adverse environmental consequences, such as dramatically increased soilerosion, siltation of streams and reservoirs, blockage of stream drainages, andloss of valuable watershed, grazing, and timber lands.

9


17/64

ard map. This map includes Seattle' sdetailed topographic database andrelated geographic data, detailed pre-cipitation data collected by theNational Weather Service, geographicinformation system support for com-

pleting the maps, and a landslidedatabase from city records that dateback to the late 1800s. USGS scien-tists are analyzing city data along withother information to determine thedegree of landslide hazard throughoutthe city. The scientists are also con-ducting studies to determine the prob-ability that landslides w ill result fromstorms of different magnitudes.

The Disaster-ResistantCommunities project has resulted inunprecedented awareness of land-

slide hazards by the private sector.For example, major mortgage bankershave realized that they hold mort-gages on many properties in areas ofsignificant landslide hazard in Seattleand elsewhere in the United Statesand are beginning to take steps toencourage homeowners to mitigatethe hazards.

An outstanding example of pub-lic-pri vate partnerships is the FederalEmergency Management Agencys(FEMA) Disaster-Resistant Communitiesproject (formerly called ProjectImpact ). Nearly 200 communities and

more than 1,100 business par tnershave embraced this project since itsincept ion in 1997. Rather than waitingfor disasters to occur, communitiestake action to reduce potentially dev-astating disasters. Seattle Washington,a city that is exposed to significantlandslide hazards, was one of the firstcommunities in the United States to

join.In conjunction w ith FEMA, the

city of Seattle collaborated with theU.S. Geological Survey (USGS) to

develop landslide hazard maps thatwi ll enable the city to be better pre-pared for landslide emergencies andto reduce losses resulting from land-slide disasters (fig. 3). The city madeavailable information needed by USGSscientists to accurately assess land-slide hazards in the area and to pro-duce a c omputer-based landslide haz-

Highlight 3Building Disaster-ResistantCommunities

Figure 3. Landslide in northw est Seattle,

Washington. Foundation of the house on

the right edge of the photograph and

the decks of neighboring houses have

been undermined. Photograph by Alan

F. Chleborad, U.S. Geological Survey.

10


18/64

Society is far from helpless in the face of these prospects.Improvements in our scientific understanding of landslides and otherground-failure hazards can provide more accurate delineation of hazardousareas and assessments of their hazard potential. This information can bedeveloped in a form and at a scale meaningful and useful for decisionmak-

ing. Cost-effective actions can be taken to reduce the loss of lives and prop-erty, damage to the environment, and economic and social disruptioncaused by landslides and other ground failures (see appendix 4 for moreinformation about mitigation techniques).

Government at all levels plays critical roles in advancing landslidehazard mitigation and developing programs and incentives that encourageand support community-based implementation. A national strategy toreduce losses from landslides and other ground failures must have bothresearch and implementation components to increase understanding oflandslides and other ground failures and put existing knowledge to use toreduce losses. Developing durable and comprehensive solutions to landslides

and other ground-failure hazards will require a continuing dialog amongand concerted action by all sectors of our society.A new public-private partnership is needed at the Federal, State, and

local levels to foster continuing cooperation among geologists, engineers,hydrologists, planners, and decisionmakers regarding landslides and othernatural hazards. This ongoing effort will, over time, help to ensure that theneeded scientific and engineering information is developed in a form usefulfor planning and decisionmaking and that such information is applied tomitigate these hazards.

A National Strategy

11


19/64

of the fl ume permit measurements offorces due to particles sliding andcolliding at the based of flows.Additional insight c an be gained byusing ultr asound imaging to "see"into the interior of flows and by

deploying "smart roc ks" containingminiature computers that record therocks accelerations as they movedown the flume.

To create a debris flow, 20 cubicmeters (about 40 tons) of saturatedsediment are placed behind a steelgate at the head of the flume and thenreleased. Alternatively, a slopingmass of sediment can be placedbehind a retaining wall at the flumehead and watered until slope failureoccurs. The ensuing debris flow

descends the flume and forms adeposit at the flume base. The flumedesign thus accommodates researchon all stages of the debris-flowprocess, from initiation throughdeposition.

FromIverson, R.M., Costa, J.E., andLaHusen, R.G., 1982, Debris f lowflume at H.J. AndrewsExperimentalForest, Oregon: U.S.Geological SurveyOpen-File Report92483, 2 p.

U.S. Geological Survey (USGS)and U.S. Forest Service (USFS) scien-tists recreate debris flows in a flumethat has been constructed to conductcontrolled experiments (fig. 4).Located about 45 miles east of

Eugene, Oregon, this unique facil ityprovides research opportunities avail-able nowhere else in the UnitedStates. USGS and USFS scientistsconduct experiments to improve theunderstanding of ground vibrationscaused by debris flows and to refineautomated debris-flow detection sys-tems. The flume also provides anideal environment for testing landslidecontrols that deflect, trap, or channel-ize debris flows. Experiments thatassess how debris flows react to and

act upon such controls can be usedto guide and evaluate engineeringdesigns.

The debris-flow flume is a rein-forced concrete channel 310 feetlong, 6.6 feet w ide, and 4 feet deepthat slopes 31 degrees, an angle typi-cal of terrain w here natural debrisflows originate. Removable glass win-dows built into the side of t he flumeallow flows to be observed and pho-tographed as they sweep past. A totalof 18 data-collection ports in the floor

Highlight 4Debris-Flow FlumeUnderstanding LandslideProcesses

Figure 4. The U.S. Geological Survey

(USGS) debris-flow flume is located in

H.J. Andrews Experimental Forest,

Oregon. The flume was constructed to

conduct controlled debris-flow experi-

ments. Photograph courtesy of the

USGS, taken September 13, 2001.

12


20/64

The National Landslide Hazards Mitigation Strategy described hereinenvisions a society that is fully aware of landslide hazards and routinely takesaction to reduce both the risks and costs associated with those hazards. Thestrategy envisions bringing together relevant scientific, engineering, construc-tion, planning, and policy capabilities of the Nation to eliminate losses from

landslides and other ground-failure hazards nationwide.The long-term mission of such a strategy is to provide and encourage theuse of scientific information, maps, methodology, and guidance for emergencymanagement, land-use planning, and development and implementation of pub-lic and private policy to reduce losses from landslides and other ground-failurehazards nationwide.

The strategic plan described in this report has nine major elements, span-ning a continuum from research to the formulation and implementation of pol-icy and mitigation objectives. Implementation of such a strategy will demand amultiyear coordinated public and private effort. All levels of government andthe private sector share responsibility for addressing these priorities andaccomplishing the objectives. Some of the objectives consist of a single, dis-crete action; others encompass a series of interdependent actions to be takenover the first 10 years of implementation. Although the primary focus is onlandslide hazards, the national strategy provides a framework for addressingother forms of ground failure as well.

The USGS has a role in each of the nine elements as a provider of land-

slide hazard information; however, the lead and participants in each elementdiffer with the nature of the element.

The NationalLandslide HazardsM itigation Strategy

13

Reaching the Goal


21/64

Research to develop a predictive understanding of landslide processes andtriggering mechanisms will be led by the USGS. Hazard identification is acornerstone of landslide hazard mitigation. Although many aspects of land-slide hazards are well understood, a much more comprehensive understandingof landslide processes and mechanisms is required to truly advance our ability

to predict the behavior of differing types of landslides. The following actionswill increase the Nations capability to forecast landslide hazards throughenhanced research, the application of new technology, and an increased under-standing of landslide processes, thresholds, and triggering mechanisms:

Develop a national research agenda and a multiyear implementationplan based on the current state of scientific knowledge concerninglandslide hazard processes, thresholds, and triggers and on the abili-ty to predict landslide hazard behavior

Develop improved, more realistic scientific models of ground deforma-tion and slope failure processes and implement their use in predicting

landslide hazards nationwide Develop dynamic landslide prediction systems capable of interactively

displaying changing landslide hazards in both space and time in areasprone to different types of landslide hazards (for example, shallowdebris flows during intense rain, deep-seated slides during months ofwet weather, and rock avalanches during an earthquake)

Efforts to delineate susceptible areas and different types of landslide haz-ards at a scale useful for planning and decisionmaking will be led by theUSGS and State Geological Surveys. Landslide inventory and landslide sus-

ceptibility maps are critically needed in landslide-prone regions of the Nation.These maps must be sufficiently detailed to support mitigation action at thelocal level. To cope with the many uncertainties involved in landslide hazards,probabilistic methods are being developed to map and assess landslide hazards(see appendix 5 for more information about mapping and assessing landslidehazards). Risk assessments estimate the potential economic impact of land-slide hazard events. Landslide inventory and susceptibility maps and otherdata are a critical first step and are prerequisite to producing probabilistic haz-ard maps and risk assessments, but these maps and data are not yet availablefor most areas of the United States. The following actions will provide thenecessary maps and assessments and other information to officials and

planners to reduce risk and losses:

Develop and implement a plan for mapping and assessing landslideand other ground-failure hazards nationwide

Develop an inventory of known landslide and other ground-failurehazards nationwide

Develop and encourage the use of standards and guidelines for land-slide hazard maps and assessments

Major Elements and

Strategic Objectives

Element 1. Research

Element 2. Hazard

Mapping and

Assessments

14


22/64

Figure 5. Portion of debris-flow hazard

map, Madison County, Virginia. From

M organ, B .A., Wiec zorek, G.F., and

Campbell, R.H., 1999, Historical and

potential debris-flow and flood hazard

map of the area affected by the June

27, 1995, storm in Madison County,

Virginia: U.S. Geologic al Survey

Geologic Investigations Series M ap

I2623B, 1 sheet.

Highlight 5M apping Debris-Flow Hazardsin M adison County, Virginia

15

A major landslide event occurredin Madison County, Virginia, in thesummer of 1995. During an intensestorm on J une 27th, 30 inches of rainfell in 16 hours. In mountainous areas,rain-saturated landslides known as

debris flows were triggered by thehundreds, causing extensive devasta-tion and one fatality.

Historical records tell us thatdestructive landslides and debrisflows in the Appalachian Mountainsoccur when unusually heavy rain fromhurricanes and intense storms soaksthe ground, reducing the ability ofsteep slopes to resist the downslopepull of gravity. For example, duringHurric ane Camille in 1969, such condi-tions generated debris flow s in

Nelson County, Virginia, 90 milessouth of M adison County. The stormcaused 150 deaths, mostly attr ibutedto debris flow s, and more than $100million in property damage. Likewise,72 hours of storms in Virginia andWest Virginia during early November1985 caused debris flows and floodingin the Potomac and Cheat Riverbasins that were responsible for 70deaths and $1.3 billion in damage tohomes, businesses, roads, and farm-lands.

Scientists fr om the U.S.Geological Survey have developed aninventory of landslides, debris flow s,and flooding from the storm of J une27, 1995, by using aerial photography,field investigations, rainfall measure-ments from rain gages, and NationalWeather Service radar observations.This inventory and a new debris-flowhazard map (fig. 5) are being used tohelp understand the conditions thatled to the floods and debris flowscaused by the 1995 summer storms inVirginia and to suggest methods ofmitigating the effects of such eventsin the future.

FromGori, P.L., and Burton, W.C., 1996,

Debris-flow hazards in the Blue Ridge

of Virginia: U.S. Geological Survey

Fact Sheet FS15996, 4 p.


23/64

Studies to monitor active landslides that pose substantial risk will be ledby the USGS. Monitoring active landslides serves the dual purpose of provid-ing hazard warning in time to avoid or lessen losses, as well as supportinglandslide research by providing new insights into landslide processes and trig-gering mechanisms. Collection of rare dynamic movement behavior data

enables the testing of landslide velocity models and the development ofimproved predictive tools applicable to other slides. Development and applica-tion of real-time monitoring of active landslides using state-of-the-art researchand telecommunications technologies are critically needed nationwide in casesof imminent risk. The following actions will provide the necessary warningand other information to officials and communities to avoid or reduce losses:

Develop and implement a national landslide hazard monitoring andprediction capability

Develop real-time monitoring and prediction capabilities on both sitespecific and regional scales, to assist Federal, State, and local emer-

gency managers determine the nature of landslide hazards and theextent of ongoing risks

Apply remote-sensing technologies such as Synthetic Aperture radarand laser altimetry for monitoring landslide movement nationwide

Incorporate state-of-the-art techniques such as microseismicity andrainfall and pore-pressure monitoring with hydrologically based modelsof slope stability and global positioning systems (GPS)

Integrate real-time monitoring capabilities with the National WeatherServices NEXRAD capabilities in selected locations nationwide

Element 3. Real-Time

Monitoring

16


24/64

Highlight 6Real-Time Monitoring ofActive Landslides

Five landslides that threaten U.S.Highway 50 and nearby homes inSierra Nevada, California, are beingmonitored by the U.S. Geological Sur-vey (USGS) after heavy rains inJanuary 1997 generated debris flow s

that bloc ked Highway 50. The cost ofreopening the highw ay was $4.5 mil-lion, with indirect ec onomic lossesfrom closure of the highway amount-ing to an additional $50 million. Tomonitor the risk posed by landslidesin this area, the USGS, in cooperationwith local, State, and other FederalAgencies, provides continuous real-time monitoring of landslide activityusing a system developed by theUSGS for monitoring active volcanoesin remote areas (fig. 6).

This system measures groundmovement and ground-w ater pres-sures every sec ond. Slope movementis recorded by instruments that detectstretching and shortening of theground (fig. 7). Ground vibrationscaused by slide movement are moni-tored by geophones buried w ithin theslide. Ground-water conditions withinthe slides are monitored by sensors,and rain gauges record precipitation.Under normal conditions, data aretransmitted to USGS computers every

10 minutes, but if strong ground vibra-tions caused by massive landslidemovement are detected, data aretransmitted immediately (fig. 8).

The USGS operates other remotereal-time landslide monitoring sites.Near Seattle, Washington, a real-timesystem monitors a slide threatening amajor railw ay, and in Rio Nido,California, another system monitors alarge landslide threatening more than140 homes. Remote monitoring alsocan record the effects of wildfire indestabilizing slopes.

FromReid, M.E., LaHusen, R.G., andEllis, W.L., 1999, Real-time monitoringof active landslides: U.S. GeologicalSurvey Fact Sheet FS9199, 2 p.

17

Figure 8. Testing a solar-powered radio

telemetry system for remote transmission

of real-time landslide data. Photograph by

Mark Reid, U.S. Geological Survey.

Figure 7. Measuring landslide movement.

Photograph by Richard LaHusen, U.S.Geological Survey.

Figure 6. Network for transmission of

real-time landslide data.


25/64

A project compiling and evaluating information on the economic impactsof landslide hazards will be led by FEMA and the insurance industry.Although losses from landslides and other natural hazards are frequent andwidespread, these losses are not consistently compiled and tracked in theUnited States. Following a landslide or other natural hazard event, a variety of

different agencies and organizations may provide damage estimates, but theseestimates usually vary widely, cover a range of different costs, and changethrough time. The National Research Council concluded in their 1999 report"The Impact of Natural DisastersA Framework for Loss Estimation" thatthere is no widely accepted framework for estimating the losses from naturaldisasters, including landslide and other ground-failure hazards. This lack ofinformation makes it difficult to set policies for coping with these hazards anddifficult to gage the cost-effectiveness of policy decisions and effectiveness ofmitigation measures. Loss data are critically needed to help government agen-cies identify trends and track progress in reducing losses from landslides. Thefollowing actions will provide a framework for compiling and assessing a

comprehensive data base of losses from landslides and other ground -failurehazards, which will help guide research, mapping, and mitigation activitiesnationwide:

Assess the current status of data on losses from landslides and otherground failures nationwide, including the types and extent of losses topublic and private property, infrastructure, and natural and culturalresources

Establish and implement a national strategy for compilation, mainte-nance, and evaluation of data on the economic and environmentalimpacts of landslide and other ground-failure hazards nationwide to

help guide mitigation activities and track progress

Element 4. Loss

Assessment

18


26/64

Three significant PacificNorthwest storm events in February1996, November 1996, and lateDecember 1996 and early J anuary1997 initiat ed widespread slope fail-ures throughout Oregon. Each of

these stormswas

declared a "MajorPresidential Disaster Declaration,"and damages to natural resourcesand infrastructure w ere extreme. Inthe Portland metropolitan region,Oregons largest cit y, more than 700slope failures were associated withthe heavy rains in 1996, with 17houses completely dest royed and 64partially condemned. An estimate ofstatewide public and private damagesincur red fr om the February 1996 eventalone is $280 million.

To better c haracterize the distri-bution and magnitude of the slopefailures associated w ith the threestorms, the Federal EmergencyManagement Agency provided fund-ing for the consolidation of a landslideinventory (fig. 9). The OregonDepartment of Geology and MineralIndustries led the consolidation effortand utilized various methods to con-tact potential data sources, informthem of the existence of the study,and request their partic ipation. This

inventory will help lead to a greaterunderstanding of regional landslideissues and assist government andcommunity agencies in devisingmeans to minimize the threat to publichealth and property that landslidespose.

Over 9,000 landslide locat ionswere incorporated into the inventory,w ith varying amounts of informationreported for each. Many other slideswere not observed or recorded, and itis estimated that two to three timesthis many landslides occur red duringthe time period. As shown on thelandslide inventory map, the vastmajority (98 percent) of the entriesare in the western portion of theState. Most of these slides occurred

Highlight 7Inventory of Slope Failures inOregon for Three 199697Storm Events

19

Figure 9. Landslide inventory for three

199697 storm events in Oregon.

in the Oregon Coast Range and Cas-cade province, wi th fewer in theWillamette Valley and Klamath Moun-tains.

FromHofmeister, R.J., 2000, Database

of slope failures in Oregon for three

1996/97 storm events: Oregon

Department of Geology and Mineral

Industries.


27/64

The effort to establish an effective system for information transfer willbe led by the USGS and State Geological Surveys. Collecting and dissemi-nating landslide hazards information to Federal, State, and local governmentagencies; nongovernmental organizations; planners; policymakers; and pri-vate citizens in a form useful for planning and decisionmaking are critically

important to an effective mitigation program. Although landslide hazardshave been studied for decades, a systematic effort to collect and distributescientific and technical information is in its relative infancy. The USGSNational Landslide Information Center is a prototype system that can beenhanced and extended into a robust nationwide system for the collection,interpretation, and dissemination of landslide hazard maps, assessments, andother scientific and landslide hazard technical information. The followingobjectives will make landslide hazard information accessible to scientists,officials, decisionmakers, and the public to assist research, planning, policy,and mitigation activities:

Evaluate and use state-of-the-art technologies and methodologies forthe dissemination of technical information, research results, maps, andreal-time warnings of potential landslide activity

Develop and implement a national strategy for the systematic collec-tion, interpretation, archiving, and distribution of this information

Element 5. Informat ion

Collection, Interpretation,

Dissemination, and

Archiving

20


28/64

An experimental monitoring andwarning system was developed andoperated jointly by the U.S. GeologicalSurvey (USGS) and the NationalWeather Service (NWS) from the1980s to 1995 in the San Francisco

Bay region (fig. 10). The system used(1) NWS protocols and outlets forissuing warnings and (2) regional net-works of NWS and USGS rain gagesand soil-moisture instruments to trackrainfall and soil-moisture c onditions.Rainfall thresholds for triggering land-slides were determined on the basisof observed relationships betweenrainfall intensity and duration and theoccurrence of landslides. When real-time data and high precision fore-casting by the NWS indicated that the

rainfall threshold for landslides had orwould soon be reached, USGS scien-tists informed the NWS to issue awarning through normal media chan-nels. The media, government officials,

Highlight 8Warning of PotentialLandslides

21

and the general public in the bay areacame to rely on these warnings andtook specific ac tions such as evacu-ating neighborhoods at particular risk.

Under the National LandslideHazards M itigation Strategy, next-gen-

eration landslide warning systems willbe implemented in landslide-proneregions nationwide. Precipitation, soilmoisture, and pore-pressure data willtelemetered in real time to networkcenters for processing and analysis.These measurements will help definethe precipitation thresholds and sup-plement the NW S NEXRAD (NextGeneration Radar) network and otherprecipitation data and forecasts pro-vided by the NWS or local agencies.Warnings of potential landslide activi-

ty that might be triggered by storms orextended rainy periods will be issuedin cooperation with the NW S andFederal and State emergency man-agement agencies.

Figure 10. Debris flow from a steep hillslope in Pacif ica, California, about 10 miles south

of San Francisco, where three children were killed and two homes destroyed on January

4, 1982. Inset, View of destroyed homes from the street . Photograph by Gerald Wieczorek,

U.S. Geological Survey. FromU.S. Geological Survey, 1995, Debris-flow hazards in the

San Francisco Bay region: U.S. Geological Survey Fact Sheet FS11295, 2 p. Available

on the web at http://greenwood.cr.usgs.gov/pub/fact-sheets/fs-0112-95/.


29/64

Efforts to develop guidelines and training for scientists, engineers, and deci-sionmakers will be led by the USGS and professional societies. The study oflandslide hazards is an area of active research and technological application, andthere is a critical need for guidelines and training for scientists and engineers in thedevelopment of landslide maps and assessments. Hazard assessments involve

assumptions and calculations about the magnitude and return frequency in specificgeographic settings. Risk assessments involve assumptions about the potentialphysical and economic impacts of landslide hazard events. The development andpresentation of the results in terms that are useful to citizens and decisionmakersare critically important to effective mitigation. Likewise, development of guidelinesand training for planners and other decisionmakers in the use of these maps andassessments are important to encouraging its appropriate use by the user community.The following are high priority objectives related to guidelines and training:

Develop and implement guidelines and training for scientists and geo-technical engineers in the use of landslide hazard and other technical

information for mapping and assessing landslide hazards Develop and implement guidelines and training for scientists and geo-technical engineers for responding to landslide disasters and providingneeded scientific and technical information for response and recoveryefforts

Develop and implement guidelines and training for planners and deci-sionmakers in the use of landslide hazard maps, assessments, and othertechnical information for planning, preparedness, and mitigation

Efforts to develop information and education programs for the user com-munity will be led by FEMA and the USGS. Before individuals and communi-

ties can reduce their risk from landslide hazards, they need to know the natureof the threat, its potential impact on them and their community, their optionsfor reducing the risk or impact, and methods for carrying out specific mitiga-tion measures. Achieving widespread public awareness of landslide hazardswill enable communities and individuals to make informed decisions on whereto live, purchase property, or locate a business. Local decisionmakers willknow where to permit construction of residences, business, and critical facili-ties to reduce potential damage from landslide hazards. The following actionswill raise public awareness of landslide hazards and encourage landslide hazardpreparedness and mitigation activities nationwide, tailored to local needs:

Develop public awareness, training, and education programs involvingland-use planning, design, landslide hazard curriculums, landslide haz-ard safety programs, and community risk reduction

Evaluate the effectiveness of different methods, messages, and curricu-lums in the context of local needs

Disseminate landslide-hazard-related curriculums and training modulesto community organizations, universities, and professional societiesand associations

Element 6. Guidelines and

Training

Element 7. Public

Awareness and

Education

22


30/64

Mount Rainier in WashingtonState is an active volcano that is cur-rently at rest betw een eruptions. Itsnext eruption may produce volcanicash, lava flows, or pyroclastic flow s(fig. 11). Pyroclastic flows are hot

avalanches of lava fragments and gasformed by volcanic eruptions.Pyroclastic flow s can rapidly meltsnow and ic e, and the resulting melt-water torrent may produce lahars (thewidely used Indonesian word for vol-canic mudflows and debris flows) thattravel down valleys beyond the baseof the volcano. Lahars may also occurduring noneruptive times w hen a sec-tion of the volcano collapses.

Lahars look and behave likerapidly flowing c oncrete, and their

impact can destroy most manmadestructures. Historically at M ountRainier, they have traveled 4550miles per hour i n thicknesses of 100feet or more in confined valleys, slow-ing and thinning as they flowed intowider valleys, most of which are pop-ulated. At Mount Rainier, lahars posea greater risk than other volcanichazards, such as lava and poisonousgases.

The likely courses of lahars arethe river valleys that drain Mount

Rainier. Four of t he five major riversystems flow w estward into suburbanareas of Pierce County. The U.S.Geological Survey mapped the likelyflow pathways and has joined withlocal, county, and State agencies todevelop a M ount Rainier hazards planthat w ill address such issues asemergency response operations andstrategies for expanded publicawareness and mitigation.

FromScott , K.M ., Wolfe, E.W., andDriedger, C.L., 1998, Mount Rainier;living w ith peri lous beauty: U.S.Geological Survey Fact SheetFS06597, 4 p. and Hobl it t, R.P.,Walde r, J.S., Driedger, C.L., Scot t,

K.M., Pringle, P.T., and Vallanc e, J .W.,1998 (rev.), Volcano hazards f romMount Rainier, Washington: U.S.Geological Survey Open-File Report98428, 11 p., 2 oversize sheets.

23

Highlight 9Alerting the Public to theHazards of M ount Rainier

Figure 11. Hazard zones from lahars, lava flows, and pyroclastic flows from Mount

Rainier. FromScott, K.M., Wolfe, E.W., and Driedger, C.L., 1998, Mount Rainier; living

with perilous beauty: U.S. Geological Survey Fact Sheet FS06597, 4 p.


31/64

Efforts to encourage mitigation action will be led by FEMA, Statedepartments of emergency services, and professional societies. A successfulstrategy for reducing landslide losses must also include a mitigation compo-nent. Mitigation actions generally fall to State and local governments, busi-nesses, and individuals. As a result, societal attitudes and perceptions can

present formidable obstacles to landslide hazards reduction. Few communi-ties have considered the full range of mitigation options despite their feasi-bility and cost effectiveness. Mitigation measures at the local level includea range of tools and techniques, such as land-use planning, regulation ofdevelopment, engineering controls, building codes, assessment districts,emergency planning and warning, and private financial and insurance incen-tives and disincentives. The following actions will facilitate and encourageimplementation of appropriate and effective mitigation measures that aretailored to local needs:

Evaluate impediments to effective planning and controls on develop-

ment and identify approaches for removing those impediments. Develop an education program for State and local elected and appoint-

ed officials that sensitizes them to the risk and costs of landslide haz-ards and encourages them to develop legislation and policies that sup-port effective landslide hazard mitigation

Develop and disseminate prototype incentives and disincentives forencouraging landslide mitigation to government agencies, the privatesector, and academia

Evaluate engineering and construction approaches to mitigate landslidehazards and develop a national plan for research to improve these tech-niques

Encourage implementation of successful landslide mitigationtechnologies

Element 8.

Implementation of Loss

Reduction M easures

24


32/64

Landslides are a significant prob-lem in several areas of Ohio, andCincinnati has one of the highest percapita costs due to landslide damageof any city in the United States.Landslides have been known to occur

in the Cincinnati area in southwesternOhio and the adjoining States ofKentucky and Indiana since beforethe 1850s, but the damage caused bylandslides has become increasinglyexpensive as urban developmentencroaches more and more on theareas hillsides. The city of Cincinnatispent an average of $550,000 per yearon emergency street repairs for dam-age due to landsl ides betw een 1983and 1987 (fig. 12).

In 1974, the Cincinnati City

Council passed an excavation and fillordinance to help reduce landslidedamage in areas of new construction.In 1989, Cincinnati c reated a geo-technical offic e within its Departmentof Public Works. The office, whic h isstaffed by a geotechnical engineer, anengineering geologist, and two tech-nicians, carries out a mitigation pro-gram. Since 1989, members of thegeotechnical staff have worked inseveral ways to reduce landslidedamage in the cit y; their work

includes engineering geologic map-ping of selected parts of the cit y,inspecting retaining walls that affectpublic right-of-w ay, reviewing pro-posed construction in hillside areas,inspecting and arranging for repair oflandslide areas that affect city prop-erty, and compiling geologic andgeotechnical data on landslide areaswithin the ci ty. In 1990, HamiltonCounty also adopted an excavationand fill ordinance to help reduce thedamage due to landslides in areas ofnew construction.

FromHansen, M .C., 1995, Geofacts:

Ohio Department of Natural

Resources, no. 8 andBaum, R.L., and

Johnson, A.M., 1996, Overview of

landslide problems, research, and

mitigation, Cincinnati, Ohio, area: U.S.

Geological Survey Bulletin 2059A,

p. A1A33.

Highlight 10Cincinnati, Ohio A Leaderin Landslide Loss ReductionMeasures

25

Figure 12. Earthflow material being

removed by a highway crew along the

Columbia Parkway, Cincinnati, Ohio. Hamil-

ton County, in the metropol itan Cincinnati

area, experienced an average annual eco-

nomic loss of $5.80 per person (1975 dollars)

between 1973 and 1978, the highest calculat-

ed per capita loss of any municipality in the

United States. Photograph courtesy of the

U.S. Geological Survey.


33/64

Efforts to develop resilient communities will be led by FEMA and Statedepartments of emergency services. Despite improved landslide hazard mitiga-tion, disasters will occur. For this reason, governments at all levels, the privatesector, and the public will need to be able to adequately prepare for, respondto, and recover from disasters involving landslides. Governments will need to

better plan for landslide emergencies. Scientists, engineers, and emergencyresponse professionals will need to be trained in the best practices to employduring a response, and public officials responsible for recovery from disasterswill need to be informed of options that will reduce future landslide losses.Incorporating the following actions in a national landslide mitigation strategywill improve the Nations ability to respond to and recover from landslide dis-asters:

Provide training for Federal, State, and local emergency managers onlandslide hazards preparedness, response, and recovery

Develop a coordinated landslide rapid response capability to assist

local, State, and Federal emergency managers in determining thenature of landslide hazards and the extent of ongoing risks

Provide dedicated landslide expertise and equipment required for rapidemergency deployment of real-time data to emergency managers, aswell as the ability to successfully transfer monitoring technology toother agencies

Element 9. Emergency

Preparedness,

Response, and

Recovery

26


34/64

Active landslides pose an increas-ing problem to older communities. Anexample of this dilemma came to ahead in April 2000, when 21 late-1950sera homes in Daly City, California,were condemned because of contin-

ued landsliding along Westline Drive.The homes w ere deemed permanentlyuninhabitable, and the c ity had nochoice but to remove their inhabitantsfrom imminent danger. By May, all res-idents had moved.

The Westline Drive landslide firstcame to the attention of Daly City res-idents in 1966, when sliding forcedthe removal of homes from a subdivi-sion developed just 7 years earlier.One more home w as removed in 1980.The movement lessened until the El

Nio w inter of 199798, one of thewettest rainy seasons on record,caused the landslide to reactivate(fig. 13). As a result, Westline Drivedropped as much as 4 feet in someareas.

The decision by the c ity to con-demn the houses was in react ion tothe local gas utili tys decision to shutoff gas service in February to theaffected area of Westline drive afterfinding numerous irreparable leaks.The utility feared that pipe ruptures

would cause an explosion. In addi-tion, the city closed off the street totraffic , including garbage and emer-gency vehicles, after discovering a10-foot-square cavity beneath thepavement.

Assisting the homeowners w as achallenge because no insurance w asavailable. The Federal EmergencyManagement Agency offered to buythe homes, but funds covered onlypart of the previous value of thehomes. The Federal Small BusinessAdministration offered mortgageloans at 4 percent, but only for areduced value of the homes, and thehomeowners had to pay off theirexisting mortgages. Daly City and SanMateo County planned to supplementthe Federal Governments $6.5 million

offer of assistance w ith housingfunds totaling $1 million. Daly Cityplanned to take over the deeds fromthe homeowners and turn the landinto open space.

FromSan Francisco Chronicle,M arch 30 and May 2, 2000, AngelicaPence, staff w riter, and RussellGraymer, U.S. Geological Survey.

Highlight 11Daly City The Human Costof Landslides

27

Figure 13. Gully retreat threatening evacu-

ated houses in Daly City, a suburb of San

Francisco, California, following the storm of

February 23, 1998. Landslide and mudslide

activity was extensively reported in the newsmedia follow ing heavy rains on February 23,

1998. A number of scattered, slow-moving

landslides had been active over the weeks

prior to the storm in San Francisco, Oakland,

and elsewhere in the San Francisco Bay

region. As most of the area experienced

about 200 percent of normal rainfall in the

winter of 1998, these landslides were proba-

bly related more to the wet winter and less to

the effects of this particular storm. However,

based on limited ground reconnaissance,

scattered slope movements directly related

to the storm did occur. Debris flows directly

triggered by the storm affected a number of

homes and properties. FromU.S. Geological

Survey web site http://landslides.usgs.gov/

html_files/landslides/reconrpt .html, 1998,

accessed Ju ly 29, 2002. Photograph by

Steve Ellen, U.S. Geological Survey.


35/64

Landslide hazard mitigation necessitates interactive collaboration amongacademia, industry, government, and the private sector. The following keyaspects of a National Landslide Mitigation Strategy will allow for rapid andsignificant progress toward a sustained mitigation of landslide hazards nation-wide:

Conduct Federal-State and public-private forums to establish regionalpriorities for research, mapping, monitoring, forecasting, and mitigat-ing landslide hazards

Establish new and enhance existing programs to fund research, map-ping, monitoring, and mitigation activities nationwide

Develop Federal-State and public-private programs to delineate land-slide prone areas, to forecast the potential for landslides, and to miti-gate losses

Establish and enhance Federal-State and public-private partnerships toleverage and maximize relevant resources and expertise

Durable and effective solutions to the Nations ground-failure-hazardproblems will require a continuing dialog among and concerted action by allsectors of our society. An effective National Landslide Hazards MitigationStrategy will require a combination of purposeful management to ensurecoordination and consortium-type decisionmaking to accommodate the multi-jurisdictional, cooperative nature of the program. An effective managementplan will include the following:

Establish coordination of the National Landslide Hazards MitigationStrategy under the leadership of the USGS, using the bureaus expert-ise and experience in landslide hazards research, monitoring, mappingand data collection, analysis, archiving, and dissemination

Establish working groups with representatives of Federal, State, andlocal governments, academia, and private industry to help coordinateand guide the National Landslide Hazards Mitigation Strategy

Establish Federal-State public-private cooperative programs to fundand encourage landslide hazard research, mapping, assessment, andmitigation efforts nationwide

Many Federal, State, and local agencies; academia; and private companiesare involved in landslide research and mitigation in the United States (seeappendixes 6 and 7 for more information about Federal, State, and local pro-grams). A National Landslide Hazards Mitigation Strategy offers new opportu-nities for mutually advantageous partnerships relating to hazard assessments,monitoring, and emergency response and recovery.

The national strategy enhances the ability of Federal, State and localagencies to partner effectively with the academic and the private sectors and toleverage shared resources. Table 1 outlines the complementary and supportiveroles and opportunities for new partnerships for each participant in theNational Landslide Hazards Mitigation Strategy.

Action Items for aNational Strategyfor ReducingLosses from

Landslides

Key Steps for

Implementation

Management Plan

New and EnhancedRoles and Partnerships

28


36/64

Table1.

Newrolesandp

artnershipopportunitiesundertheNationalLandslideHazardsMitigationStrate

gy.

Element

Current

Newrolesandpartn

ershipopportunities

status

Federal

State

Local

Private

Academic

1.Research.

Amuchmorecomprehensive

Coordinateresearchpriorities

Developingapredictive

understandingoflandslide

understandingof

processesandmechanismsis

Conductresearch

landslideprocessesand

requiredtoadvanceourability

triggeringmechanisms

topredictthebehaviorof

Useresultsofresearchinpolicy,planning,andmitigationdecisions

differenttypesoflandslides.

2.HazardMappingand

Landslideinventoryand

Maplandslides

Assessments.

landslidesusceptibilitymaps

onFederallands

Delineatingsusceptible

arecriticallyneededinmany

Establishmappingand

areasanddifferenttypes

landslide-proneregionsofthe

assessmentstandards

oflandslidehazardsat

Nation.Ingeneral,thereare

-

Mapandassesslandslidehazards

ascaleusefulforplanning

nostandardsformappingand

Uselandslidehazardmapsandassessmentsinplanning,preparedness,andmitigatio

n

anddecisionmaking

assessments.

3.Real-Time

Real-timemonitoringof

Improvereal-timemonitoringcapabilities

Monitoring.

activelandslidesiscritically

Monitoringactive

needednationwide.

landslidesthatpose

Monitorlandslidesandestablishlandslidewarningsystems

substantialrisk

4.LossAssessment.

Lossesarenotconsistently

Est

ablishandimplement

Compilingandevaluating

compiledandtrackedinthe

anationalstrategy

informationonthe

UnitedStates.

for

compilation,

economicandenviron-

maintenance,and

mentalimpactsofland-

eva

luationofdata

slidehazards.

Compileand

sharerecordsoflosses

5.Information

Thereisnosystematic

Developrobustlandslidehazards

Co

llectanddistributeneeded

Developandshare

Collection,

nationwidecollectionor

informationclearinghousesystem

informationtodecisionmakers

information

Interpretation,

distributionoflandslide

forthesystematiccollection,

Dissemination,and

hazardsinformation.

interpretation,archiving,and

Archiving.

distributionofscientificand

Establishingan

technicalinformation,

databases,

effectivesystem

andmaps

forinformationtransfer

29


37/64

Table1.

NewrolesandpartnershipopportunitiesundertheNationalLandslideHazardsMitigatio

nStrategy.

Continued

Element

Current

Newrolesa

ndpartnershipopportunities

status

Federal

State

Local

Private

Academic

6.Guidelinesand

Thereisacriticalneedfor

Developandimplementguidelinesandtrainingcurriculums

Training.

guidelinesandtrainingfor

Developingguidelines

scientists,engineers,planners,

Participateintrainingprograms

andtrainingfor

anddecisionmakers.

scientists,engineer

s,

anddecisionmakers

7.PublicAwarenes

s

Thereislittlepublicawareness

andEducation.

andunderstandingoflandslide

Developandimplementpublicawarenessandeducationprograms,invo

lvingland-use

Developinginform

ation

hazards,impactsoncommuniti

es,

planning,design,andlandslid

ehazardcurriculums;landslidehazardsafety

andeducationprog

rams

oroptionsforreducingrisk.

andcommunityriskreduction

fortheusercommunity

8.Implementation

of

Mitigationnecessarilyoccurs

Developandencouragepolicies

Adoptandimplementpolicies

LossReduction

atthelocallevel;therefore,

thatsupportlandslidehazard

andpracticesthatsupport

Measures.

implementationofloss

mitigation

landslidehazards

Encouragingmitigation

reductionmeasuresvaries

Developfinancialincentives

mitigation

action

fromcommunitytocommunity

.

anddisincentivesthat

supportlandslidehazard

mitigation

Serveasconsult

antsandadvisors

Developandencourage

engineeringandconstruction

approachestomitigate

landslidehazards

9.Emergency

Federal,

State,andlocal

ProvidetrainingforFederal,

Participate

Provideexpertiseduringemergencies

Preparedness,Resp

onse,

governments;the

State,andlocalemergency

intraining

andRecovery.

privatesector;and

managers

Developingresilient

thepublicneedtobeableto

Developacoordinatedlandslide

Effectivelyrespondtolandslide

communities

adequatelyprepare,respondto,

rapidresponsecapability,

emergencies

andrecoverfromlandslide

includinglandslidehazards

emergencies.

expertiseandequipment

Implementpolicies

requiredforrapidemergency

thatreducefuture

deploymentofreal-timedata

landslidelosses

toemergencymanagers

30


38/64

Implementation of the National Landslide Hazards Mitigation Strategywithin the USGS Landslide Hazards Program (LHP) will involve fourprincipal tasks

Expansion of work performed by scientists in the Landslide HazardsProgram

Establishment of new Cooperative Landslide Hazard Assessment andMapping Program

Establishment of a new Cooperative Federal Land ManagementLandslide Hazards Program

Establishment of new partnerships for the Landslide Hazard LossReduction Program

The USGS Landslide Hazard Program is currently funded for $2.26 mil-lion in FY 2002. The changes above will require expansion of and additionalfunding for the LHP.

Expanding efforts by USGS scientists in the areas of research, hazardassessment, monitoring, public information, and response will be necessaryto meet the challenges of the national strategy. The Landslide HazardsProgram will also require additional funding to meet new responsibilities tocoordinate activities within the Federal Government to fully implement thestrategy. Approximately $8 million in new funding will be required to supportthe following:

Additional research on landslide processes and triggering mechanisms(element 1) ($1.5 million)

Additional hazard maps and assessments of landslide-susceptible areas,including developing standards and guidelines (element 2) ($2 million)

Additional monitoring of active landslides and improvement of state-of-the-art research and telecommunications technology (element 3)($2 million)

Improved information collection, interpretation, dissemination, andtechnology transfer, including public awareness programs and educa-tion (elements 5 and 7) ($1 million)

Expanded emergency response and recovery capability and activities(element 9) ($1 million)

Coordination of National Landslide Hazard Mitigation Strategy ($0.5million)

A new cooperative program will be established to encourage the under-standing and mitigation of landslide and other ground-failure hazards byStates, Territories, counties, and other local jurisdictions. The program will beadministered by the USGS Landslide Hazards Program. The primary goal ofthis cooperative program will be to reduce hazard losses by increasing theavailability of assessments and maps of landslide- and other ground-failure-prone areas in the United States. This program will address all elements of the

Funding for theUSGS to Implementa National Strategyfor Reducing

Losses fromLandslides

Expansion of the Work

Performed by Scientists

in the Landslide

Hazards Program

Establishment of a New

Cooperative Landslide

Hazard Assessment and

M apping Program

31


39/64

national strategy, with a primary focus on element 2, landslide hazard mappingand assessments. The USGS will provide guidance to encourage standardizedassessment and map products that will be available digitally.

Priorities will be determined annually in consultation with State andTerritory representatives. Grants to States and Territories will be awarded

competitively. States and Territories will determine priorities and the size ofgrants to be distributed to their local jurisdictions in consultation withStatewide and Territorywide advisory committees.

Approximately $8.0 million will be required to support competitive grantsto the States, Territories, and local jurisdictions each year. Each grant will bematched by a 30 percent State or Territory contribution to encourage thedevelopment and use of landslide information in planning and mitigationactions at the State and local levels. It is anticipated that all States andTerritories will participate in such a program and that grants will average$150,000 per State or Territory.

A new program, administered by the USGS Landslide Hazards Program,will be established to increase and encourage the understanding and mitigationof landslide hazards on Federal lands, including assessment and mapping oflandslides, land-use planning and facility siting, emergency management, andpublic education.

The goal of such a program will be to reduce losses from landslide andother ground-failure hazards through more informed and, therefore, betterstewardship of Federal lands under the jurisdiction of the National ParkService, the Bureau of Land Management, the Bureau of Reclamation, theBureau of Indian Affairs, and the U.S. Forest Service. The new program willaddress all elements of the national strategy, with a primary focus on landslide

hazard mapping, assessments, and monitoring (elements 2 and 3).Priorities for scientific and technical assistance for Federal land manage-

ment agencies will be determined annually in consultation with representativesof Federal land management agencies. Approximately $2.0 million will berequired for scientific and technical assistance for Federal land managementagencies. It is anticipated that the program will support approximately 20agreements, averaging $100,000 each. Most of these funds will be used tosupport hazard assessments and procure monitoring equipment, with USGSstaff providing technical assistance

Establishment of a NewCooperative Federal

Land M anagement

Landslide Hazards

Program

32

Documents

Usgs - National Landslide Hazards Mitigation Strategy