Last month, north of Rio de Janero in Brazil was overcome with mudslides that seems to have been triggered by heavy rainfall. It is being said that this is the greatest natural disaster in Brazil's history. It is estimated that greater than 1300 people were killed in these landslides and severe flooding.
Mudslides outside Rio de Janero, Brazil Source: The Seattle Times
Houses being built in the areas where these landslides occurred also contributed to the slides by putting more force on the unstable earth. This goes to show that there needs to be studies done before constructions of houses or buildings are built. These engineering studies should show that the land was not stable and houses or other buildings probably should not have been Other techniques besides aviodance include building a wide range of barriers at the bottom of the slopes. There are three main ways to help stablize a slope including:
- Changing to shape of the slope
- Lowering the level of the groundwater or lowering the amount of water present in the earth material by drainage
- Mechanical methods such as barriers or anchors (see the picture below)
Stabilizing the slope. Source: The full wiki.
For more pictures of the flooding and landslides in Brazil: Disasterous photos from 2011 Brazilian landslides