What are three types of erosion that can affect a river valley?

Three types of erosion that can affect a river valley are hydraulic action, abrasion, and attrition. Hydraulic action refers to the force of moving water eroding the river banks, abrasion is the process of rocks and sediment in the water wearing away the riverbed, and attrition occurs when rocks in the river collide, break down, and become smoother over time.