Explanation: Potholes are variously shaped depressions of different dimensions that are developed in the riverbed by excessive localized erosion by the streams.

Explanation: A valley may be defined as a low land surrounded on sides by inclined hill slopes and mountains. Every major river is associated with a valley of its own.

Explanation: Waterfalls are magnificent jumps made by a stream or river water at certain specific parts of their course where there is a sudden and considerable drop in the gradient of the channel.

Explanation: Convex flood plains are the most common type and are associated with many major rivers of the world.

Explanation: Deltas are defined as alluvial deposits of roughly triangular shape that are deposited by major rivers at their mouths, i.e., where they enter a sea.

Explanation: A typical simple delta is commonly made of three layers of which only the top layer may be sub aerial, that is exposed on the surface.

Explanation: The fore-sets are the intermediate layers and often show very steep inclination. The fore-set beds are made up of thick layers of sand and clay.

Explanation: Three conditions necessary for the formation and growth of a delta are: absence of any strong sea currents; presence of good quality of load in the stream and the slope of seashore where the stream enters the seawater must necessarily be quite gentle and wide.

Explanation: Kickpoints are actually places of steep drops in elevation in the course of a river. These are very often caused due to presence of rocks of unequal hardness at those places.