Post on 05-Jan-2016
EROSI
Types of Erosion
1. Water Erosion
2. Wind Erosion
3. Gravitical erosion
4. Frozen melt Erosion
Water Erosion
Raindrops washes out seed and splashes soil into the air
If the fields are on a slope the soil is splashed downhill which causes deterioration of soil structure. Soil that has been detached by raindrops is more easily moved than soil that has not been detached.
Sheet erosion
Types of Water Erosion
Sheet erosion the uniform removal of soil in thin layers from sloping land
the loose soil merely runs off with the rain RAINDROPS
Rill erosion It occurs when soil is removed by water from little streamlets that run through land with poor surface draining.
Gully erosion an advanced stage of rill erosion, just as rills are often the result of sheet erosion
Sheet erosion
Rill erosion
Gully erosion
Wind erosionWind erosion is the movement and deposition of soil particles by wind
Wind erosion occurs when soils bared of vegetation are exposed to high-velocity wind. When its velocity overcomes the gravitational and cohesive forces of the soil particles, wind will move soil and carry it away in suspension
Occurring mostly in flat, dry areas and moist sandy soils along bodies of water, wind erosion removes soil and natural vegetation, and causes dryness and deterioration of soil structure.
Surface texture is the best key to wind erosion hazard potential
Gravitical erosion
mass movement of soil - slides, slips, slumps, flows and landslides - gravity is the principal force acting to move surface materials such as soil and rock
occurs when the weight (shear stress) of the surface material on the slope exceeds the restraining (shear strength) ability of that material
Factors increasing shear stress include erosion or excavation undermining the foot of a slope, loads of buildings or embankments, and loss of stabilizing roots through removal of vegetation.
Frozen-melt erosion
When water freezes, it expands suddenly and with tremendous force
When water inside a crack in a rock freezes, its expansive strength may be sufficient to crack the rock and to break parts off it.