The term landslide or, less frequently, landslip,refers to several forms of mass wasting that include a wide range of ground movements, such as rockfalls, deep-seated slope failures, mudflows and debris flows. Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients: from mountain ranges to coastal cliffs or even underwater, in which case they are called submarine landslides.
Gravity is the primary driving force for a landslide to occur, but there are other factors affecting slope stability which produce specific conditions that make a slope prone to failure. In many cases, the landslide is triggered by a specific event (such as a heavy rainfall, an earthquake, a slope cut to build a road, and many others), although this is not always identifiable.
Natural causes of landslides include:
- saturation by rain water infiltration, snow melting, or glaciers melting;
- rising of groundwater or increase of pore water pressure (e.g. due to aquifer recharge in rainy seasons, or by rain water infiltration);
- increase of hydrostatic pressure in cracks and fractures;
- loss or absence of vertical vegetative structure, soil nutrients, and soil structure (e.g. after a wildfire – a fire in forests lasting for 3–4 days);
- erosion of the toe of a slope by rivers or ocean waves;
- physical and chemical weathering (e.g. by repeated freezing and thawing, heating and cooling, salt leaking in the groundwater or mineral dissolution);
- ground shaking caused by earthquakes, which can destabilize the slope directly (e.g. by inducing soil liquefaction), or weaken the material and cause cracks that will eventually produce a landslide;
- volcanic eruptions
Landslides are aggravated by human activities, such as:
- deforestation, cultivation and construction;
- vibrations from machinery or traffic;
- blasting and mining;[8]
- earthwork (e.g. by altering the shape of a slope, or imposing new loads);
- in shallow soils, the removal of deep-rooted vegetation that binds colluvium to bedrock;
- agricultural or forestry activities (logging), and urbanization, which change the amount of water infiltrating the soil.
ELIF KOC
FATIH BILIM VE SANAT MERKEZI
BIANCA GIANGRANDE
IC Sante Giouffrida
Catania
Pupil GIULIA N.
CATANIA TEAM
STUDENT: MARCO C
CHRISTINA KOKOTI
PRIMARY SCHOOL TEMENI EGIO
STUDENTS: KONSTANTINA- LOYKI -ANDROMAXI
-VASILIS-KELA
MEHTAP OZCE COMERTOGLU
TEVFIK YARAMANOGLU PRIMARY SCHOOL ELAZIG
STUDENT ARDA GURBUZ
NAMIK KEMAL ORTAOKULU
TURKEY
MELTEM SEVIM KAYAOGLU
STUDENT SELIN
Hazards are mitigated mainly through precautionary means—for instance, by restricting or even removing populations from areas with a history of landslides, by restricting certain types of land use where slope stability is in question, and by installing early warning systems based on the monitoring of ground conditions such as strain in rocks and soils, slope displacement, and groundwater levels.
Published: Jun 28, 2019
Latest Revision: Jun 28, 2019
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