In a river, the water surface typically has less current or flow velocity compared to the water deeper inside the river. This difference in flow velocity can be attributed to the frictional effects and the interaction of the water with the riverbed and banks.


Near the river surface, the water encounters more resistance from the air, vegetation, and any obstacles present, which slows down its flow. This phenomenon is known as "boundary layer" effects, where the water in direct contact with the river surface experiences more friction and moves at a slower speed compared to the deeper layers of the river.


As we move deeper into the river, away from the boundaries, the effects of friction decrease, and the water experiences less resistance. The deeper layers can flow more freely and at a higher velocity due to reduced frictional forces acting on them.


This variation in flow velocity from the water surface to deeper inside the river is also influenced by other factors, such as the river's shape, the presence of rocks or obstacles on the riverbed, and the overall river topography.


In summary, the water surface in a river has less current than inside the water due to the frictional effects with the surroundings, resulting in slower flow near the boundaries. As we move deeper into the river, the friction decreases, allowing the water to flow more freely and at a higher velocity.