Landslides

Soil Themes > Landslides

Principles
Impacts
Landslides in Europe
Landslides and the EU Soil Thematic Strategy
JRC role and expertise
Online publications
Contact points

Principles

A landslide is the gravitational movement of a mass of rock, earth or debris down a slope. Landslides are usually classified on the basis of the material involved (rock, debris, earth, mud) and the type of movement (fall, topple, avalanche, slide, flow, spread). Thus, the generic term landslide also refers to mass movements such as rock falls, mudslides and debris flows. Volcanic mudflows and debris flows are also called lahars.

Shallow landslides usually involve only the soil layer and upper regolith zone, while deep-seated landslides additionally involve bedrock at higher depth. Landslide volume can vary from some tens of cubic metres to several cubic kilometres for giant landslides, while landslide speed may range from a few centimetres per year for slow-moving landslides to tens of kilometres per hour for fast, highly destructive landslides. According to the state of activity or movement, existing landslides can be classified as active, dormant (potentially reactivated) or inactive (often relict or fossil).

Landslides are generally induced when the shear stress on the slope material exceeds the material’s shear strength. The occurrence and reactivation of landslides is conditioned by a number of terrain and geo-environmental factors related to bedrock and soil properties, weathering conditions, jointing and structure, slope morphology, land cover/use, surface and ground water flow, etc.

Landslides can be triggered by natural physical processes such as heavy or prolonged rainfall, earthquakes, volcanic eruptions, rapid snow melt, slope undercutting by rivers or sea waves and permafrost thawing. They can also be triggered by man-made activities such as slope excavation and loading (e.g. road and buildings construction, open-pit mining and quarrying), land use changes (e.g. deforestation), rapid reservoir drawdown, irrigation, blasting vibrations, water leakage from utilities, etc, or by any combination of natural and/or man-induced processes.

Landslide in Veneto, Italy

Impacts

Landslides are a major hazard in most mountainous and hilly regions as well as in steep river banks and coastlines. Their impact depends largely on their size and speed, the elements at risk in their path and the vulnerability of these elements. Every year landslides cause fatalities and result in large damage to infrastructure (roads, railways, pipelines, artificial reservoirs, etc.) and property (buildings, agricultural land, etc.).

Large landslides in mountainous areas can result in landslide dams blocking river courses. These natural dams cause valley inundation upstream and can be subsequently breached by lake water pressure, hence generating deadly flash floods or debris flows downstream. Submarine and large coastal cliff landslides can trigger tsunami, as can landslides in lake and reservoir shores.

Landslides can also affect mine waste tips and tailings dams and landfills, causing fatalities and contaminating soils and surface and ground water

In areas affected by landslides, these are a major source of soil erosion and sediment yield to valleys and rivers.

Landslides in Europe

Landslide occurrence

Landslides occur in many different geological and environmental settings across Europe. For example, large rockfalls, rockslides, rock avalanches and debris flows dominate in the Alps and steep slopes in other mountain ranges; slides and flows abound in flysch belts of Slovakia, Czech Republic, Poland, Italy, Spain, France and other countries; slides of various types are numerous on cliffs and steep slopes in Southern and Eastern England’s coast and Bulgaria’s Northern Black Sea coast; shallow slides and mudflows occur on Ireland’s peat slopes; slides and lateral spreads do as well on gentle slopes in quick clays in Sweden and Norway; flows and slides also typically occur in clay-rich sediments and sedimentary sequences in Tertiary basins as well as on river banks, etc.

Intense and/or long-lasting rainfall represents the most frequent trigger of landslides in continental Europe. However, earthquakes are also responsible for some large landslides. Human activities are also the cause of many slope failures in infrastructure and built-up areas.

Landslides are a major factor of landscape evolution in mountainous and hilly regions in Europe. In addition to causing extensive erosion and sediment yield in these regions, large landslides have been responsible for the creation of many lakes in the Alps and other mountain ranges by damming river valleys. Examples of this include the lakes of Santa Croce, Antrona (formed in 1642), Alleghe (formed in 1771) and Scanno in Italy, Eibsee and Obersee in Germany, Blindsee in Austria, Vallon in France (formed in 1943), and Sils, Silvaplana, Oeschinen and Davos in Switzerland. Most landslide dams, however, have often formed temporary lakes that have later breached the dam causing catastrophic flash floods and debris flows. Today, hills in some alpine valley bottoms are remnants of large deposits from giant landslides (e.g. from prehistoric rock avalanches with volumes even in excess of 1 km3 such as Flims, Sierre and Tamins in Switzerland, Köfels, Fernpass and Tschirgant in Austria, etc.). Many landslide-dammed lakes have been progressively filled with sediments, thus also modifying the valley environment. Unfortunately, the hazard of river damming from landslides still exists in these regions: outstanding examples are those of La Clapière and Séchilliene rockslides in the French Alps, whose potential movement acceleration threatens communities located far from the unstable slopes. On the other hand, landslides in steep coastal areas including cliffs accelerate erosion and subsequent cliff retreat by sea waves.

Giant subaerial landslides are not exclusive of the Alps. They have also occurred in prehistoric times in areas such as southern Crimea in Ukraine, Isle of Skye in UK, and especially in the Canary Islands, Spain. In the latter, a number of huge debris avalanches entered the ocean triggering tsunami. Evidence of large tsunami are also found in Scotland and other coastal areas bordering the Norwegian Sea, mainly attributed to the Storegga submarine megaslide (ca. 3,500 km3) off the west coast of Norway. In the Mediterranean, landslide-triggered tsunami have been observed dominantly in the Corinth Gulf, Greece, and the Aeolian Islands, Italy. Recent examples include the local tsunami caused by the collapse of the Nice airport embankment in 1979 and the small to moderate tsunami produced by a landslide on the Stromboli Island flank in 2002.

Nowadays, population growth and expansion into landslide-prone areas is raising landslide risk in Europe. In addition, an increase of landslide events is expected in the future due to climate change.

Major historic landslide disasters

There is a long record of landslide disasters in historical and recent times in Europe causing many fatalities and high economic losses. Major disasters include, among others, those of Goldau (1806), Elm (1881) and Gondo (2000) in Switzerland; Piuro (1618), Antronapiana (1642), Roccamontepiano (1765), Monte Antelao (1814, 1925), Vajont (nearly 2000 killed by reservoir wave caused by man-induced landslide, 1963) and, more recently, Valpola (1987) and rainfall-triggered multi-landslide events in Piedmont region (1994), Sarno and Quindici (1998) and Messina (2009) in Italy; Granier (1248) and Plateau d’Assy (1970) in France; Granada province (earthquake-triggered multi-landslide event, 1884) in Spain; Mount Dobratsch (1348) in Austria; Getå (1918) and Tuve (1977) in Sweden; Verdal (1893) and landslide-triggered local tsunami at Loen (1905, 1936) and Tafjord (1934) in Norway.

In addition, landslides occurring in mine waste tips and tailings dams have been the origin of the catastrophes of Sgorigrad, Bulgaria (1966), Aberfan (1966) in Wales, UK, and Stava (1985) in Trento, Italy.

Lessons learnt from the management of a number of landslide disasters occurred in Europe in the 1990s and early 2000s are reported here

Online landslide inventories in Europe

Austria
A subset of the large mass movements database of Austria GEORIOS (GEORIsikenÖsterreich) is available online. This is called the Mass Movements (Massenbewegungen) database, and includes some 860 occurrences.
Website: http://geomap.geolba.ac.at/MASS/index.cfm
Contact: Geological Survey of Austria (GBA)

Belgium
An inventory of landslides in the Flemish Ardennes is available on http://dov.vlaanderen.be/dov/DOVInternet/default.htm
Contact: Flemish Government, Department of Environment, Nature and Energy

France
Landslide inventory data for France are available within the database “Mouvements de terrain” (BDMvt)
Website: http://www.bdmvt.net/
Contact: Bureau de recherches géologiques et minières(BRGM)

Germany
A landslide inventory of the Bavaria Federal State is available online as a layer (“Georisiken – Massenbewegungen”) of the GeoFachdaten Atlas of the Bayerisches Landesamt fur Umwelt
Website: http://www.bis.bayern.de/bis/initParams.do

Italy
A comprehensive landslide inventory of the country including some 470,000 landslides has been carried out within the project IFFI (Inventario dei Fenomeni Franosi in Italia)
IFFI Project website: http://www.sinanet.apat.it/progettoiffi
Contact: Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA)

Landslides and the EU Soil Thematic Strategy

Landslides are one of the soil threats considered in the EU Thematic Strategy for Soil Protection and the related Proposal for a Soil Framework Directive. The Strategy calls for actions and means for the protection and sustainable use of soils as a physical platform on which human activities are developed. The proposed Directive, in turn, will be the Strategy implementing tool. This will mainly require to identify landslide and other soil threat risk areas in the European Union, set risk reduction targets for those areas and establish programmes of measures by Member States to achieve them.

JRC role and expertise

The JRC Soil Action provides scientific and technical support to the European Commission Services for implementation of the EU Soil Thematic Strategy both through its own work activities and in collaboration with external partners. Our main activities include harmonisation of methods for landslide mapping in Europe (inventory, susceptibility, hazard and risk), development of satellite, airborne and ground-based remote sensing techniques for long term monitoring of landslides, analysis of lessons learnt from management of past landslide disasters, and spatial database management. Find more information here

The JRC coordinates a European landslide expert group and participates in the EU Framework Programme 7 project SAFELAND (Living with landslide risk in Europe: Assessment, effects of global change, and risk management strategies). JRC has also participated in previous EU landslide-related research projects including GALAHAD, MUSCL, RUNOUT, ENVASSO and RAMSOIL.

JRC is a member of the International Consortium on Landslides (ICL). JRC staff are also members of the European Centre on Geomorphological Hazards (CERG).

Landslides Expert Group

The JRC has created in late 2007 a landslides expert group to provide it with advice and assistance regarding its scientific and technical activities in support to EU soil policy making and research. Find more information about:

On-line Publications

Barredo, J.I., Benavides, A., Hervás, J., van Westen, C.J., 2000. Comparing heuristic landslide hazard assessment techniques using GIS in the Tirajana basin, Gran Canaria Island, Spain. International Journal of Applied Earth Observation and Geoinformation, 2: 9-23.
Barredo, J.I., Hervás, J., Lomoschitz, A., Benavides, A., van Westen, C.J., 2000. Landslide hazard assessment using GIS and multicriteria evaluation techniques in the Tirajana basin, Gran Canaria Island. Proc. 5th EC GIS Workshop, Stresa, Italy, 28-30 June 1999. EUR 19018 EN, Office for Official Publications of the European Communities, Luxembourg, pp. 355-365.
Günther, A., Reichenbach, P., Hervás, J., 2008. Approaches for Delineating Areas Susceptible to Landslides in the Framework of the European Soil Thematic Strategy. Proceedings of the First World Landslide Forum, Tokyo, 18-21 November 2008, pp. 235-238.
Herrera, G., Ponce de León, D., Mulas, J., Llorente, M., Hervás, J., Noferini, L., Mecatti, D., Macaluso, G., Tamburini, A., Federici, P., 2007. Ground Based SAR and Terrestrial Laser Scanner data for the analysis of the Formigal landslide; the GALAHAD project test site in the Spanish Pyrenees. 7th Geomatics Week, Barcelona, Spain, 20-23 February 2007, CD-ROM, 2 pp.
Herrera, G., Ponce de León, D., Mulas, J., Llorente, M., Hervás, J., Luzi, G., Mecatti, D., Noferini, L., Macaluso, G., Pieraccini, M., Tamburini, A., Federici, P., 2007. Landslide ground based remote sensing monitoring: Formigal case study (Huesca, Spain). Geophysical Research Abstracts, 9, EGU2007-A-07945.
Hervás, J. (Ed.), 2003. Lessons Learnt from Landslide Disasters in Europe. EUR 20558 EN, European Commission, Ispra, Italy, 91 p.
Hervás, J. (ed.), 2003. Recommendations to deal with Snow Avalanches in Europe. EUR 20839 EN, Office for Official Publications of the European Communities, Luxembourg, 81 pp.
Hervás, J., Barredo, J.I., 2001. Evaluación de la susceptibilidad de deslizamientos mediante el uso conjunto de GIS, teledetección y métodos de evaluación multicriterio. Aplicación al Barranco de Tirajana (Gran Canaria). Proc. V Simposio Nacional sobre Taludes y Laderas Inestables. Madrid, 27-30 November 2001. CEDEX, Ministerio de Fomento, Madrid, pp. 305-316.
• Hervás, J., Barredo, J.I., Rosin, P.L., Pasuto, A., Mantovani, F., Silvano, S., 2003. Monitoring landslides from optical remotely sensed imagery: the case history of Tessina landslide, Italy. Geomorphology, 54: 63-75.
Hervás, J., Bobrowsky, P., 2009. Mapping: Inventories, Susceptibility, Hazard and Risk. In: Sassa, K. and Canuti, P. (Eds.), Landslides - Disaster Risk Reduction. Springer, Berlin, ISBN 978-3-540-69966-8, pp. 321-349.
Hervás, J., Günther, A., Reichenbach, P., Guzzetti, F., Chacón, J., Pasuto, A., Trigila, A., Malet, J.-P., Tagliavini, F., 2008. Towards a common approach for mapping areas susceptible to landslides in Europe. Geophysical Research Abstracts, 10, EGU2008-A-12200.
Hervás, J., Rosin, P.L., 2001. Tratamiento digital de imágenes de teledetección en el espectro óptico para el reconocimiento y control de deslizamientos. Proc. V Simposio Nacional sobre Taludes y Laderas Inestables. Madrid, 27-30 November 2001. CEDEX, Ministerio de Fomento, Madrid, pp. 63-74.
Jelinek, R., Hervás, J., Wood, M., 2007. Risk Mapping of Landslides in New Member States. JRC Scientific and Technical Reports EUR 22950 EN, Office for Official Publications of the European Communities, Luxembourg, 34 pp.
Lomoschitz, A., Hervás, J., Yepes, J., Meco, J., 2008. Characterisation of a Pleistocene debris-avalanche deposit in the Tenteniguada Basin, Gran Canaria Island, Spain. Landslides, 5: 227-234.
Malet, J.-P., Thiery, Y., Puissant, A., Hervás, J., Günther, A., Grandjean, G., 2009. Landslide susceptibility mapping at 1:1M scale over France: exploratory results with a heuristic model. In: Malet, J.-P., Remaître, A., Boogard, T. (Eds), Proc. International Conference on Landslide Processes: from Geomorphologic Mapping to Dynamic Modelling, 6 -7 February 2009, Strasbourg, France. CERG Editions, Strasbourg, pp. 315-320.
Malet, J.-P., Thiery, Y., Puissant, A., Hervás, J., Guenther, A., Grandjean, G., 2009. Landslide susceptibility mapping at 1:1M scale over France. Geophysical Research Abstracts, 11, EGU2009-3274.
Rosin, P.L., Hervás, J., Barredo, J.I., 2000. Remote sensing image thresholding for landslide motion detection. In: Petrou, M. (Ed.), Proc. 1st International Workshop on Pattern Recognition Techniques in Remote Sensing (PRRS 2000), Andorra, 1 September 2000, BMVA Press, pp. 10-17.
Rosin, P.L., Hervás, J., 2002. Image thresholding for landslide detection by genetic programming. In: Bruzzone, L. and Smits, P.C. (eds), Analysis of Multitemporal Remote Sensing Images. World Scientific, Singapore, pp. 65-72.
Rosin, P.L., Hervás, J., 2005. Remote sensing image thresholding methods for determining landslide activity. International Journal of Remote Sensing, 26: 1075-1092.
Schweigl, J., Hervás, J., 2009. Landslide Mapping in Austria. JRC Scientific and Technical Report EUR 23785 EN, Office for Official Publications of the European Communities, Luxembourg, 61 pp. ISBN 978-92-79-11776-3.

Contact Points

Javier Hervas,
Tel: +39 0332 785229; Fax: +39-0332-786394, E-mail: javier.hervas@jrc.ec.europa.eu

Miet Van Den Eeckhaut,
Tel: +39 0332 786289; E-mail: miet.van-den-eeckhaut@jrc.ec.europa.eu

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