Here's why:
* Thin sheet of water: This indicates that the water flow is not concentrated in channels or gullies. Instead, it spreads out over a relatively large area.
* Downhill: This indicates that gravity is the driving force behind the water movement.
Sheet erosion is a gradual process where the water slowly removes topsoil and carries it away. It can have a significant impact on soil fertility and can lead to other forms of erosion like rill erosion if left unchecked.
