EROSION

Types of erosion comprise the wearing away of the land by running water, rainfall, wind, ice or other geological agents, including such processes as detachment, entrainment, suspension, transportation and mass movement. Geologically, erosion is defined as the process that slowly shapes hillsides, allowing the formation of soil cover from the weathering of rocks and from alluvial and colluvial deposits. Erosion due to human activities as an effect of careless exploitation of the environment results in increasing run-offs, decline of arable layers, siltation in lakes, lagoons and oceans. As a result of erosion, aquatic systems productivity may increase (through intake of nutrients and other growth factors) or decrease (through increase turbiduty, decreased euphotic layer and primary productivity) somtimes leading to death of essential life-support systems (e.g. coral reefs, sea-grass beds) .