drrr

• Landslide


  The mass movement of rock, soil, and debris down a slope due to gravity
• Landslides


  • Downward movement of geological materials such as soil and rock
• Types of landslide


  • Debris slides and flow
  • Rockfall and topples
  • Creep
  • Mudslides
• Debris slides and flow


  When debris from rockfalls and slumps mix with water, they can transform into debris slide that can travel great distances
• Rockfall and topples


  Involved rocks, are extremely rapid and can travel great distance. They usually occur in a cliff or steep slopes where rocks basically fall out or roll over in great speed
• Creep


  Generally slow, involve soil, and travel short distances. Creeps create soil ripples that looks like miniature folds or small wave-like figures along the slopes. Aside from that, you will also notice that trees, fences and electrical post on the areas tend to lean or tilt to the downward direction of the slope, implying that area is affected with geological creep movement. Usually occur on gentle to moderate slopes
• Mudslides


  Generally involved saturated soils moving at extremely rapid velocities and travel great distance
• Sinkhole


  Depressions or openings in the ground surface as the result of a collapse in the ceiling of an underground cavity or cavern
• Sinkholes


  • Areas of ground that have no natural external surface drainage – when it rains, all the water stays inside the sinkhole and typically drains into the subsurface
  • Can vary from a few feet to hundreds of acres and from less than 1 to more than 100 feet deep
  • Can develop slowly or form suddenly when a collapse occurs
• Types of Sinkholes


  • Dissolution sinkholes
  • Cover-subsidence sinkholes
  • Cover-collapse sinkholes
• Dissolution sinkholes


  Occur where there is little soil or vegetation over the soluble rock. Aggressive dissolution occurs where flow is focused in pre-existing openings in the rocks, such as long joints, fractures, and bending planes, or in the zone of water table fluctuations where the ground water is contact with the atmosphere. They typically develop gradually
• Cover-subsidence sinkholes


  Tend to develop gradually where the covering sediments are permeable and contain sand
• Cover-collapse sinkholes


  Tend to develop abruptly and cause catastrophic damages. They occur where the covering sediments contain significant amounts of clay