Solution is a transport mechanism that occurs only in aqueous environments. Solution involves the eroded material being dissolve and carried along in water as individual ions. Particle weight, size, shape, surface configuration, and medium type are the main factors that determine which of these processes operate. The erosional transport of material through the landscape is rarely continuous. Instead, we find that particles may undergo repeated cycles of entrainment , transport , and deposition .
Transport depends on an appropriate balance of forces within the transporting medium.
A reduction in the velocity of the medium, or an increase in the resistance of the particles may upset this balance and cause deposition. Reductions in competence can occur in a variety of ways. Velocity can be reduced locally by the sheltering effect of large rocks, hills, stands of vegetation or other obstructions. Normally, competence changes occur because of large scale reductions in the velocity of flowing medium. For wind, reductions in velocity can be related to variations in spatial heating and cooling which create pressure gradients and wind.