Erosion and Deposition

Erosion is the acquisition and transportation of rock debris. When massive rocks break into smaller fragments through weathering or any other process, erosional geomorphic agents — running water, groundwater, glaciers, wind and waves — remove and transport this material to other places, depending on the dynamics of each agent. The rock debris carried by these agents also aids erosion greatly through abrasion, the grinding and scraping action of particles against surfaces.

By erosion, relief degrades — the landscape is worn down. This means that although weathering aids erosion, it is not a pre-condition for erosion to take place. Weathering, mass-wasting and erosion are all degradational processes, but it is erosion that is largely responsible for the continuous changes the earth's surface undergoes. Denudational processes like erosion and transportation are controlled by kinetic energy.

The erosion and transportation of earth materials is brought about by five agents: wind, running water, glaciers, waves and groundwater. Of these, the first three — wind, running water and glaciers — are controlled by climatic conditions. They represent three states of matter: gaseous (wind), liquid (running water) and solid (glacier). The work of the other two agents, waves and groundwater, is not controlled by climate. In the case of waves, it is the location along the interface of the lithosphere and hydrosphere — the coastal region — that determines their work. The work of groundwater, on the other hand, is determined more by the lithological character of the region. Only if the rocks are permeable and soluble, and water is available, does karst topography develop. …