Soil erosion is the wearing away, detachment and removal of soil material from one place to another place through the agents like water, wind, ice etc. Soil erosion is a serious challenge which has many effects on social and economic activities. Some of these effects are explained below:-
(i) Loss of productive soil. When the to productive soil is eroded it is lost forever only the unproductive stony soil is left behind the consequently is the lowering of agriculture productivity of land.
(ii) Depict of vegetation cover. The eroded land cannot hold the plants including crops are washed away or are buried in the deposit soil way from their original location.
(iii) Destruction of structures. when erosion takes place bridges can being taken away from their original areas . other structures like road ,railways, as well as buildings can collapse after erosion of soils.
(iv) Pollution to environment. Eroded soil that is carried into rivers lake s and oceans may contain chemical pollutants collected by water from farm and dumping grounds, hence resulting to loss of aquatic organisms.
(v) Provides sand for building and construction activities. sand which is eroded from steep slope is deposited on river bed from where it is scoped when the water flows in the river has diminished or even stopped. The sand is then used for construction purpose this is common in river at Bunju Dar es salaam and most parts of kisarawe II in coastal region.