Soil of Bangladesh-IV.
Floodplain soils are developed in floodplain alluvium. Piedmont soils are developed in Piedmont alluvium (at the foot of hills). Thirteen general soil types are included in this group, including peat soils. They occupy about 80 percent of the land area of Bangladesh. Rapidly flowing river water carries a mixture of sand, silt and clay. As the speed of the moving water slackens, first the sand particles are deposited, then the silt and lastly the clay particles. Therefore, sand is deposited on river banks, where the speed of the river current is first reduced. Further away from river banks, flood water deposits silty materials first, then clay. Since sand particles are much bigger than silt and clay particles, the result is that river banks are gradually raised in level relative to the adjoining land.Show more [+] Less [-]