Definition - What does Sheet Erosion mean?
Sheet erosion is used to describe a form of erosion that takes away surface material in a manner that is more or less even across the surface of a large area. It can be contrasted with erosion, which happens along a well defined channel or line and creates or increases ravines and gullies.
Safeopedia explains Sheet Erosion
Sheet erosion is caused by rainfall, especially the force of raindrops impacting onto bare soil with none or minimal plant life present to absorb impact. This dislodges soil and when spread evenly over the surface of the soil can erode soil in sheets. This can happen with the first impact of rain hitting the soil and can also happen when water does not channel, but rather moves evenly down a slope.