Landslides'++Cause+(Before)

=~CAUSES OF LANDSLIDES!~=

Landslides can be very dangerous or they can be very minor. Landslides can happen on there own and with out warning. People who live on hillsides have to aware of when and where a landslide might strike. All landslides have two things in common - they are the result of failure of the soil and rock materials that make up the hill slope and they are driven by gravity. They can vary in size from a single boulder in a rock fall or topple to tens of millions of cubic metres of material in a debris avalanche. Landslides can be triggered by natural causes or by human activity. One big cause of landslides is rain. The night or week before a landslide there might have been a lot of rain. For example in the La conchita landslide, the night before water was pouring from the sky. All that water was sucked into the hillside, the water just kept being sucked in. Until one day (the day after) the hillside just couldn't take it anymore. So it just let it out and there's a landslide. 1179417274

Geologists use a variety of classification schemes to describe causes of landslides. Because of wide variety of causes, no single scheme has yet been developed that address or describe all types of landslides. Even the terms assigned to types of landslides are undergoing standardization among geological and scientific international agencies. Some of these will be illustrated in the guidebook, but for an example of a classification scheme that has been widely used outside the U.S. see the following: =External= 1. Gradient 2. Height 3. Slope length 1. Natural 2. Human-induced 1. Natural 2. Human-induced 1. Single 2. Multiple/continuous =Internal= 1. Expansion, swelling 2. Fissuring 3. Strain softening 4. Stress concentration 1. Physical property changes, swelling 2. Chemical changes 1. Removal of cements 2. Removal of fines 1. Saturation 2. Rise in water table 3. Excess pressures 4. Drawdawn 1181792494Soraya Yousefi
 * 1) Geometrical change
 * 1) Unloading
 * 1) Loading
 * 1) Shocks and Vibrations
 * 1) Progressive failure (internal response to unloading, etc.)
 * 1) Weathering
 * 1) Seepage Erosion
 * 1) Water Regime Change