Dry soils can act like a sponge to bring groundwater to the surface. An area of land supplying water to a watercourse bounded by hills or ridges which direct the flow of water. An area in the lowest portion of a catchment where water is released. Discharge is maximised where the watertable is at or very close to the soil surface, where there is little vegetation, or where soil properties tend to encourage water to move towards the surface. The process whereby soils separate into their constituent particles in water.
Dispersible soils are highly erodible.
A large area draining to the base of a catchment. A typical situation occurs following the tree clearing from hillslopes, which reduces transpiration and allows an increase in rainfall intake beyond the root zone and a rise in watertables lower down the slope. Increased subsurface seepage dissolves salts in the soil and, with lateral flow through the landscape, moves from hillslopes to valley floors. Salty water surfaces in patches depending on the geomorphology and topography of the site. The salt becomes concentrated by evaporation at these locations and the normal vegetation is killed.