Landslides
What is Landslide?
Landslides is a geological phenomenon which includes a wide range of ground movements. They can occur on any terrain given the right conditions of soil, moisture,and angle of slope. Landslides sere to redistribute soil and sediments in a process that an be in abrupt collapses or in slow gradual slides. It is also known as mud flows, debris flows, earth failures.
http://www.ussartf.org/landslides.htm
Landslides usually occurs on a mountainous places or elevated places. This is due to heavy rains,earthquakes,deforestation,etc. Many people were greatly affected by this kind of disasters. Many crops and roads were destroyed and many lives were affected.
What causes landslides?
Landslides can be triggered by gradual processes such as weathering or by external mechanisms including:
-
Undercutting of a slope by stream erosion, wave action, glaciers, or human activity such as road building,
-
Intense or prolonged rainfall, rapid snow melt, or sharp fluctuations in ground-water lees,
-
Shocks or vibrations caused by earthquakes or construction activity, and
-
loading on upper slopes.
Once a landslide is triggered,material is transported by various mechanism including sliding, flowing and falling. Landslides often occur along planes of weakness that may parallel the hill slope.
What are the effects of landslides?
Landslides may result directly or indirectly from the activities of people. Slope failures can be triggered by construction activity that undercuts or overloads dangerous slopes, or that redirects the flow of surface or ground-water. Landslides kill people, destroy trees, crops and other plantations.
This catastrophe could drastically affect everyone who lives near an elevated area. A single but relatively strong rainfall, thunderstorm, hurricane / tropical depression could make the soil erode, which will cause immense flooding, and will, definitely rage on the residents below.
However, all this can be prevented if illegal logging, and other unscrupulous practices against mother nature could be checked and controlled.
http://www.em.gov.bc.ca/mining/GeolSurv/Surficial/landslid/Is1.htm
<Back Next>
