It forms gullies and canyons. The movement of ground water is controlled largely by the porosity and permeability of the rocks through which it flows. The water table is the surface below which all pore spaces in the rocks are saturated with water. Inartesian systems, it is moved by hydrostatic pressure. The natural discharge of ground water is generally into streams, marshes, and lakes.
Artesian water is confined under pressure, like water in a pipe.
It occurs in permeable beds bounded by impermeable formations. Erosion by ground water produces karst topography, characterized by sinkholes, solution valleys, and disappearing streams. Water flows from high to low due to pressure difference 3. Constant motion though slow 4. Glaciers are systems of flowing ice that form where more snow accumulates each year than melts.