Which of the following statements is correct regarding Drainage pattern? 1. Antecedent Drainage cut through the newly formed landform and maintain the same path. 2. Superimposed Drainage cut deeper through the existing landform and maintain the same path.
The flow of water through well-defined channels is known as ‘ drainage ’ and the network of such channels is called a ‘ drainage system ’. Discordant drainage A pattern of drainage that bears no relation to the structure of the underlying rock. It can be Superimposed or Antecedent drainage. Superimposed Drainage System The drainage pattern developed on rock strata that have been removed by erosion is known as superimposition . Superimposed Drainage cut deeper through the existing landform and maintain the same path. Hence, Statement 2 is correct. The Superimposed drainage is also known as Epigenetic or Superinduced Drainage. Examples : The Damodar , the Subarnarekha , the Chambal , the Banas , and the rivers flowing at the Rewa Plateau, rivers of the eastern USAand southern France . Antecedant Drainage System The drainage pattern was already present before a period of uplift and folding . During an uplift , the rivers were able to cut down at the same rate and so maintain their courses . Hence, Statement 1 is correct. This process is called antecedence and the drainage system thus developed is called antecedent drainage . TheHimalayan rivers have antecedent origin i.e. these rivers existed even before the Himalayan ranges were uplifted . Example : The Indus , Satluj , Alaknanda , Gandak , Kosi , Brahmaputra all have an antecedent origin. They run transverse to the mountain ranges cutting deep V-shaped, steep-sided valleys, deep gorges, etc.