The movement of soil, mud and rock due to the downward movement of wind, water or ice.

This process is called Erosion

Explanation:

Erosion is the movement of soil or rock or dissolved materials from the surface of the earths crust due to the effect of water, wind or ice to another location completely. erosion is completely a surface action is doesn't affect the core of the earth.  while in the case of weathering it is the removal of soil or rock particles or dissolved material caused also by water or ice but without displacing the removed particles i.e no movement as seen in the case of Erosion.

Erosion caused by wind is as common as erosion caused by water,because water especially flood water causes most of the erosion like Gully erosion which is a very dangerous erosion if not checked on time.

c.) the country needed a stronger central government.