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(fast-moving slurries of water, soil, and rock) as they travel down steep slopes, especially those that enter stream channels where they may mix with additional water and sediment.
Are a common occurrence in terrain with steep topography and soils that have degradable strength.
RAINFALL-INDUCED HAZARDS
2TYPES OF RAINFALL-INDUCED GEOLOGIC HAZARDS
landslide Sinkhole
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• do not happen on flat grounds.
• Because of the angle on the ground, gravity induces the land to move downward.
• Water is a natural agent for erosion, and if rain or any source of water frequently flows down a sloping area, the gravitational descent of loosened soil makes it possible for landslides to occur.
LANDSLIDE
4• A landslide, also called ______ it is a ground movement on a sloping terrain.
"landslip",
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• Are depression or holes on the ground that resulted from the collapse of the surface layer of the soil.
The rocks can be weakened further by frequent submersion in water, such as when there is repeated rainfall or an unmanaged flood.
The rocks dissolve in water and gradually weaken, carving and forming spaces and underground passages for water.
SINKHOLES
6• It occur in areas where the soil foundation is made of soft minerals and rocks such as limestone, salt beds, or any acidic rocks.
SINKHOLES
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It is used to measure the slope angle, soil compaction, and soil strength of an area.
• The data determine the level of risks to landslides.
• The same data can also be used for future terrain alterations or guide to urban planners to plan a safer structural development in any areas
Abney level or a laser rangefinder
8Abney level or a laser rangefinder parts
Slow-motion Screw
Magnifying Glass
Pinhole
Draw tube
Vernier Scale
Vertical Degree Plate
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- Sinkholes are validated using a GPR to provide images of subsurface ground.
-It can detect the types of objects, changes in material, and voids and cracks under a layer of soil.
-It is why it is a good tool in determining whether sinkholes may occur or not.
Ground Penetrating Radar(GPR)