DRRR 3rd QTR Lessons

• Words associated with DRRM-related laws and policies


  • RISK REDUCTION
  • HYOGO
  • SENDAI
  • RESPONSE
  • MITIGATION
  • REHABILITATION
  • RECOVERY
  • WARNING
  • COORDINATION
  • STAKEHOLDERS
  • COMMUNITY
  • GOVERNMENT
  • CAPACITY
  • PLAN
  • MOBILE ALERT
• The Philippines is highly exposed to natural hazards because it lies along the Pacific typhoon belt and is within the Pacific Ring of Fire
• Landslides


  Occur when masses of rock, earth, or debris move down a slope

  
• Debris flows


  A common type of fast-moving landslide that tends to flow in channels

  
• Types of landslide movement


  • Falls
  • Topples
  • Slides (rotational and translational)
  • Flows

  
• Falls


  • Involve the collapse of material from a cliff or steep slope, usually involving a mixture of free fall, bouncing or rolling, resulting in the collection of rock or debris near the base of a slope

  
• Topple failures


  • Involve the forward rotation and movement of a mass of rock, earth or debris out of a slope, generally occurring around an axis (or point) at or near the base of the block

  
• Talus cone


  A debris or debris cone that forms at the base of a slope after a topple

  
• Rotational slides


  • Have a listric (curved or spoon-shaped) slip surface where the upper surface of the displaced material may tilt backwards toward the scarp
• Translational slides


  • Occur along a distinctive planar surface of weakness such as a fault, joint or bedding plane, can be very rapid where discontinuities are steep, and are not self-stabilising
• Flows


  Landslides that involve the movement of material down a slope in the form of a fluid, often leaving behind a distinctive, upside-down funnel shaped deposit

  
• Types of flows


  • Mud flows
  • Debris flows
  • Rock avalanches

  
• Landslide materials


  • Soil
  • Debris
  • Rock
  • Garbage

  
• Landslide triggers


  • Intense rainfall
  • Weathering of rocks
  • Ground vibrations created during earthquakes
  • Volcanic activity
  • Overloading on the slope

  
• Common signs of impending landslides


  • Tension cracks
  • Fractured rocks and sediments
  • Sliding slope and active slides
  • Soil overburden

  
• Overburden


  The rock or soil layer that needs to be removed in order to access the ore being mined
• Ways to minimize landslide risks


  • Hazard mapping
  • Public information
  • Engineering intervention

  
• Shotcrete


  A method of applying concrete proposed at high velocity primarily on a vertical or overhead surface
• Vetiver grass significantly helps reduce landslides and soil erosion and also improves crop yields
• Sinkholes


  Holes in the ground that form when water dissolves surface rock, often limestone
• Landslide treatment techniques


  • Land use improvement
  • Drainage management
  • Surface erosion control
  • Erosion control in rills
  • Erosion control in gullies
  • Slope failure due to slope cutting or steep slope
  • Slope failure due to heavy load on slope upstream of landslide

  
• Mulching


  The act of covering the soil with organic material such as bark, wood chips, leaves, etc. to preserve moisture and improve soil condition
• Brush layering


  Consists of live cut branches and rooted plants placed in layers into excavated terraces and filled with compacted soil material, for deeper soil stabilization
• Fascines


  Dormant branch cuttings bound together into long cylindrical bundles and placed in shallow trenches on slopes to reduce erosion and shallow sliding
• Contour grass planting


  Plowing and planting across slope contours creates man-made water breaks that allow water to enter the soil and settle the topsoil without washing it down the slope
• Palisade


  A technique used for erosion control in small gullies
• Check dams


  Structures made of brushwood, stone, boulders, gabions, masonry, or concrete, used for erosion control in gullies
• Crib walls


  Walls made of bamboo, poles, or concrete, used to address slope failure due to slope cutting or steep slope
• Retaining or toe walls

  Walls made of stone, gabion, masonry, or concrete, used to address slope failure due to slope cutting or steep slope

  
• Anchoring


  Bolting the rock bed, used to address deep-seated landslides that affect national structures like hydropower or highways

  
• Excavation


  Removing rock and soil from the head of a landslide to reduce the driving force, used to address slope failure due to heavy load on slope upstream of landslide

  
• Filling rock


  At the toe of a landslide to increase resistance against movement, used to address slope failure due to heavy load on slope upstream of landslide

  
• Tropical Cyclone


  (also known as a typhoon or hurricane)

  
• You'll know I'm coming up to a week before I arrive
• I have many names, but you've probably never met me
• Eventually I will slow down and disappear
• I can destroy most things
• I'm a killer; I can crush you, drown you, and make you sick
• I can be hundreds of miles across
• I can be more powerful than a nuclear bomb