soil resources

Top layer of soil that contains decayed parts of once living things. 

• clay
• sand
• humus
• silt

Soil erosion means

• The removal of the bottom soil cover by water, wind and human activities

• The removal of the top soil cover by water, wind and human activities

• The removal of the middle soil cover by water, wind and human activities

• The removal of the top soil cover by celestial activities

_______________ leads to Sheet erosion on hilly slopes.

• Afforestation

• Deforestation

• Reafforestation

• Construction of dams

How are Gullies formed?

• Presence of vegetation leads to formation of rills and then during heavy rains Gullies are formed.

• Absence of vegetation leads to formation of rills and then during heavy rains Gullies are formed.

Removal of vegetation for land use like railways, roads, buildings and agriculture has caused

• Rill erosion

• Sheet erosion

• Gully erosion

• All of the above

saltation means

• 0.1-0.7mm– size soil particles bouncing or hopping fashion due to wind

• 0.1-0.6mm– size soil particles bouncing or hopping fashion due to wind

• 0.1-0.5mm– size soil particles bouncing or hopping fashion due to wind

Soil creep is

• greater than 0.5mm– size soil particles moving in rolling fashion due to wind

• greater than 0.6mm– size soil particles moving in rolling fashion due to wind

• greater than 0.7mm– size soil particles moving in rolling fashion due to wind

Wind erosion occurs in areas that have sandy or coarse bare soils(without any vegetation).

• True

• False

Occurs on gentle slopes, and is slow removal of thin layer of Soil.

• Stream erosion

• Sea erosion

• Sheet erosion

• Rill erosion

Continuation of sheet erosion for long finger shaped rills or grooves are formed is called

• Gully erosion

• Rill erosion

• Sea erosion