DRRR GEOLOGICAL Flashcards
are gradual or sudden natural earth processes which cause injury, loss of life, property damage, loss of livelihood and services, social and economic disruption, or environmental changes
geological hazards
is a ground movement on a sloping terrain
landslide
Southwest Monsoon that brings heavy rainfall during the months of June-October
Habagat
Trade Winds from NorthEast hardly brings any rainfall
Amihan
3 major causes of landslides
- Geology
- Morphology
- Human Activity
– refers to the material of the soil or rock in an area or can be the layers of
earth have weakened or stiffened in some part.
geology
– refers to the structure of the land. The soil or rock has weakened through
loss of vegetation or root system which holds the soil in place. Another is prolonged rainfall or heavy water leakage that increases the weight of the land mass therefore
as the water flows, sediments and soil comes with it
morphology
– to make way for agriculture and construction, trees are needed to be cut down, irrigation, deforestation, and excavation can weaken the integrity of the
earth.
human activity
3 basic types of landslides
- Fall
- Flow
- Slide
when soil, or rock, or both starts to detach from a steep slope along a surface on which little or no shear
displacement has occurred.
fall
is recognized as the forward rotation out of a slope of a mass of soil or rock material around a point or axis below the center of gravity of the
displaced mass
topple/tumble
occurs when the head of the displaced material may move almost vertically downward, and the upper surface of the displaced material may tilt backwards toward the scarp
slide
a rotational slide where you can observe several parallel planes
slump
occurs due to liquefaction or flow or extrusion of the underlying softer material
spread
s a spatially continuous movement in which the surfaces of shear are
short-lived, closely spaced, and usually not preserved. The component velocities in the displacing mass of a flow resemble those in a viscous liquid.
flow
are essentially large, extremely rapid, often open-slope flows formed when an unstable slope
collapses and the resulting fragmented debris is rapidly transported away from the slope
debris avalanche
can occur on gentle to moderate slopes, generally in fine-grained soil,
commonly clay or silt, but also in very weathered, clay-bearing bedrock. These types of landslides can range from very
slow (creep) to rapid and catastrophic
earthflow
is the informal name for a slow earthflow and consists of the imperceptibility
slow, steady downward movement of slope-forming soil or rock
creep
a landslide that occurs due to prolonged or heavy rainfall, increasing the weight of the land mass
rain-induced landslide
is a depression or hole in the ground caused by some form of collapse of the surface layer
sinkhole
4 types of sinkholes
- solution dissolution
- cover subsidence
- cover collapse
- artificial sinkholes
It occurs in areas where calcareous is exposed on the ground or where thin layers of soil and permeable sand are also covered
solution dissolution sinkhole
This occurs when the bedrock is covered with deep layer of soil and earth. A crack starts once the bedrock begins to get eroded. Weak points begin to form in the layers of soil above. The weak points
eventually become a large hole within the bedrock that cannot support the
weight above it.
cover collapse sinkhole
This occurs when the bedrock is covered with
soil ad materials that are not well-knitted together. The soil in these areas are
mostly made of clay or sand. Once the bedrock starts to erode, the clay or
sand starts to enter through the cracks and settles into the space left behind,
creating a cavity on the surface of the soil. I
cover subsidence sinkhole
