Which statement is true regarding the transport of overland flow?

The statement that overland flow reduces velocity is correct because as water flows over land surfaces, it encounters various forms of resistance, such as vegetation, soil roughness, and topography. These elements collectively slow down the movement of water. The irregularities of the surface cause friction and turbulence, which impede the flow and ultimately lead to a decrease in its velocity.

In addition, as the flow interacts with plants, their roots and leaves can capture some of the flowing water, leading to its temporary retention before it continues its journey. Moreover, the presence of sediment and debris along the flow path can further contribute to the reduction in water speed. Together, these factors work to minimize the overall velocity of overland flow.

While some might consider the potential for increased velocity in specific scenarios—such as when water pools or channels narrow—on the whole, the diverse natural elements and conditions encountered during overland flow typically serve to reduce its speed. Understanding this concept is essential for implementing effective erosion and sedimentation control practices, as managing flow velocity can minimize soil erosion and surface runoff.