Change in the salinity status of the soil. It can be caused by improper management of irrigation schemes, mainly in the arid and semiarid regions covering small areas or it may also occur if seawater or fossil saline groundwater intrudes in coastal regions or in closed basins with aquifers of different salt content when there is an excessive use of groundwater. It usually takes place where human activities lead to an increased evapotranspiration in soils on salt containing parent material or with saline groundwater.