- Category: Uncategorised
- Published: 20 October 2013
The World Landslide Forum (WLF) is a triennial mainstream conference aimed at gathering scientists, stakeholders, policy makers and industry members dealing with the management of landslide risk. The First World Landslide Forum, organized by the International Consortium of Landslides (ICL), UNESCO, WMO, FAO, UNISDR, UNU, UNEP, IBRD, UNDP, ICSU, WFEO, KU and the Japan Landslide Society, was held in 2008 at the United Nations University, Tokyo. The 1st WLF adopted the 2008 Tokyo Declaration “Strengthening the International Programme on Landslides with UNISDR”.
The numerous recent disasters due to landslides show that there is an urgent need to translate science into practical applications to assist communities, governments and disaster-relief organizations avert and mitigate future landslide disasters. For this reason, the explicit theme of the Second World Landslide Forum, being organized for Rome, Italy for 3-9 October 2011, is to connect landslide scientists with landslide stakeholders in a special landslide forum to align future innovations in landslide science and technology with the future needs of humanity and the environment.
Along with earthquakes and floods, landslides constitute one of the more important natural hazards, and in some countries, such as Japan, they are a major cause of natural-hazard deaths. Landslides are perceptible gravitational movements of masses of rock, earth and debris down slopes. Their dynamics depend on the style of movement (mainly falls, slides and flows and, secondarily, topples and spreads) and the materials involved (Cruden & Varnes, 1996). Rapid and slow landslides can be identified, and speed is clearly a major source of danger. Landslide occurrence and reactivation is conditioned by a number of terrain and geo-environmental factors such as rock and soil properties, weathering, jointing and structure, slope morphology, land cover/use, and water flow. Landslides can be triggered by many natural phenomena such as heavy or prolonged rainfall, earthquakes, volcanic eruptions, snow melt and erosion of the base of slopes by rivers or sea waves. They can also be triggered by human activities such as slope excavation and loading, land-use change, blasting vibrations, and water leakage from utilities, or by many combinations of activities and processes.
The Forum will discuss major impacts of landslides on the environment, including effects on people, their homes and possessions, farms and livestock, industrial establishments and other structures, and lifelines, including submarine ones. In addition, the Forum will encourage discussion of the effects of landslides on the natural environment, i.e., on (1) the morphology of the Earth’s surface, particularly that of mountain and valley systems, both on continents and beneath oceans; (2) the forests and grasslands that cover much of the continents, and (3) the native wildlife on the Earth’s surface and in its rivers, lakes, and seas. Also, landslides are a major destroyer of humanity’s cultural heritage, such as at Orongo (Easter Island), Petra (Jordan), Cappadocia (Turkey) and many sites in Italy.
- Category: Landslide
- Published: 20 October 2013
A landslide or landslip is a geological phenomenon which includes a wide range of ground movements, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments. Although the action of gravity is the primary driving force for a landslide to occur, there are other contributing factors affecting the original slope stability. Typically, pre-conditional factors build up specific sub-surface conditions that make the area/slope prone to failure, whereas the actual landslide often requires a trigger before being released.
The Mameyes Landslide, in the Mameyes neighborhood of barrio Portugués Urbano in Ponce, Puerto Rico, which buried more than 100 homes, was caused by extensive accumulation of rains and, according to some sources, lightning.
Landslides occur when the stability of the slope changes from a stable to an unstable condition. A change in the stability of a slope can be caused by a number of factors, acting together or alone. Natural causes of landslides include:
- groundwater (pore water) pressure acting to destabilize the slope
- Loss or absence of vertical vegetative structure, soil nutrients, and soil structure (e.g. after a wildfire(e.g.fire in forests etc.lasting for 3–4 days)
- erosion of the toe of a slope by rivers or ocean waves
- weakening of a slope through saturation by snow melt, glaciers melting, or heavy rains
- earthquakes adding loads to barely stable slope
- earthquake-caused liquefaction destabilizing slopes
- volcanic eruptions
Landslides are aggravated by human activities, such as
- deforestation, cultivation and construction, which destabilize the already fragile slopes.
- vibrations from machinery or traffic
- earthwork which alters the shape of a slope, or which imposes new loads on an existing slope
- in shallow soils, the removal of deep-rooted vegetation that binds colluvium to bedrock
- Construction, agricultural or forestry activities (logging) which change the amount of water which infiltrates the soil.
World Landslide Forum's role is to contribute to landslide research, practice, education and decision making and are willing to strengthen landslide and other related Earth system risk reduction strategies.
This article uses material from the Wikipedia article <a href="http://en.wikipedia.org/wiki/Landslide">"Landslide"</a>, which is released under the <a href="http://creativecommons.org/licenses/by-sa/3.0/">Creative Commons Attribution-Share-Alike License 3.0</a>.