Water Erosion

Water erosion is usually caused by rainfall and runoff down a slope. However, the magnitude of impact differs according to the type of soil. We know the following 4 types of water erosion: sheet erosion is defined as a collective removal of soil in thin layers each time raindrops hit the surface, dislodging it. Even though the effects show gradually, their cumulative impact is enormous. Most vulnerable is a land with little or none vegetation. Mildly eroded flows of water, no more than 30 cm (12 inches) deep in the soil, are caused by rill erosion. This form of erosion occurs when surface water accumulates in narrow points and consequently erodes soil. This is common in bare soil. Significantly deeper and wider drainage channels are known as gully erosion. They start to form when surface water is trapped in small, accumulated streams and are deeper than 30 cm (12 inches). The last form of water erosion is known as bank erosion. It occurs continuously as banks, rivers and streams are naturally worn away.