On genetic basis, the valleys are classified into the following types:
1. Consequent Valley: The valley formed by the initial streams that originate in a particular region in accordance with the initial slope of the land is called Consequent Valley. These valleys develop mainly in newly formed parts, volcanic regions and coastal plains. These valleys develop on the initial surface of elevated terrain in accordance to the slope.
2. Subsequent Valley: The valley formed by streams originated after the consequent stream and joining the master consequent at right angles is called Subsequent Valley. These valleys are found usually in regions with soft rocks.
3. Obsequent Valley: The valley formed by streams flowing in a direction opposite to that of the dip of the rock strata, i.e. opposite to the master consequent stream is called Obsequent Valley. After the formation of subsequent valleys, river tributaries of the river flowing in them are developed.
4. Resequent Valley: The valley formed by streams which flow in the direction of the initial consequent stream but join the subsequent streams, thereby developing in response to a new base level.
5. Insequent Valley: The river valley that remains unaffected by the regional slope and geological structure is called Insequent Valley.
