GENERAL GEOLOGY

Detailed explanation-1: -(d) Drainage density: It is defined as the sum of lengths of all the streams divided by the catchment area. In general as drainage density increases, flow velocity increases, infiltration decreases, base period decreases and peak discharge increases.

Detailed explanation-2: -The drainage density is the measure of the length of stream channel per unit area of drainage basin. Mathematically it is expressed as: drainage density = stream length / basin area. A drainage network is a system of interconnected stream channels found in a drainage basin.

Detailed explanation-3: -Drainage density is a measurement of the sum of the channel lengths per unit area. It is generally expressed in terms of miles of channel per square mile. Horton (1945, pp. 283-284) and Langbein (1947, p.

Detailed explanation-4: -The correct option is A Area drained by a river and its tributaries. The area drained by a river and its tributaries is called a drainage basin. The Amazon basin, located in northern South America, was the largest drainage basin in the world.

Detailed explanation-5: -Stream density is the length of all channels within the basin divided by the area of the basin. Stream density is one of the most important characteristics for evaluating potential runoff. A drainage basin with a large number of tributaries has a higher stream density than a basin with very few tributary streams.