Class IX – Drainage

Ans. Drainage describes the river system of an area.

Ans. The area drained by a single river system is called a drainage basin.

Ans. (i) The Himalayan Rivers

(ii) The Peninsular Rivers.

Ans. Perennial rivers are those rivers which receive water from rain as well as from melted snow from the lofty mountains.

Ans. These rivers are non-perennial because they are dependent on rainfall.

Ans. The major Himalayan rivers are the Indus, the Ganga and the Brahmaputra.

Ans. A river along with its tributaries may be called a river system.

Ans. The Zaskar, the Nubra, the Shyok and the Hunza join it in the Kashmir region.

Ans. The Bhagirathi.

Ans. Tributary is a stream flow into the large stream/river and increase the water volume of the main river. Distributary is a stream/river which flows away from a large river. It decreases the volume of water of the main river.

Ans. It is due to the fact that it is a cold and a dry area.

Ans. On reaching the Namcha Barwa (7757 m) Brahmaputra take a ‘U’ turn and enters India in Arunachal Pradesh through a gorge.

Ans. (i) Tibet – Tsang Po

(ii) Bangladesh – Jamuna

Ans. Mahanadi, the Godavari, the Krishna and the Kaveri.

Ans. the Narmada and the Tapi.

Ans. (i) The Marble rocks near Jabalpur

(ii) Dhuadhar falls

Ans. Godavari

Ans. The hard rock bed and lack of silt and sand does not allow any significant meandering. Many rivers, therefore, have straight and linear courses.

Ans. (i) The river Kaveri makes the second biggest waterfall in India, known as Jog falls.

(ii) The hydroelectric power generated from the falls is supplied to Mysuru, Bengaluru and the Kolar Gold field.

Ans. Dal Lake

Ans. Most of the fresh water lakes are in the Himalayan region due to their glacial origin.

Ans. It is introduced in June 2014 for abatement of pollution, conservation and rejuvenation of the Ganga.

Ans. (i) The Himalayan rivers have long courses from their source to the sea.

(ii) They perform intensive erosional activity in their uppoer courses and carry huge loads of silt and sand.

(iii) In the middle and lower courses, these rivers form meanders, Oxbow lakes and many other depositional features in their flood plains.

(iv) They have also well-developed deltas.

Ans. (i) The Himalayan rivers are better placed for irrigation due to their perennial nature and less fluctuation in water discharge. They get water from rain as well as from melted snow from the lofty mountains.

(ii) On the other hand, the peninsular rivers are rain fed. They almost dry up during the wather before and after the rainy season, with the exception of the Kaveri which has enough water throughout the year. These rivers, therefore, do not provide ideal conditions for the irrigation.

Ans. (i) It rises in Tibet near Lake Mansarovar.

(ii) It forms a picturesque gorge in Jammu and Kashmir.

(iii) Its tributaries in the Kashmir region are the Zaskar, the Nubra, the Shyok and the Hunza.

(iv) The Satluj, the Beas, the Ravi, the Chenab, the Jhelum join together and enter the Indus near Mithankot in Pakistan.

(v) The Indus plain has a very gentle slope.

(vi) Its total length is 2900 km and is one of the longest rivers in the world.

(vii) About one-third of Indus basin is located in India in the states of Jammu and Kashmir, Himachal Pradesh and the Punjab and the rest is in Pakistan.

Ans. (i) Some tributaries of the Ganga are major rivers such as the Yamuna, the Ghaghara and Gandak and the Kosi.

(ii) The river Yamuna rises from the Yamunotri Glacier in the Himalayas.

(iii) It flows parallel to the Ganga and as a right bank tributary meets the Ganga at Allahabad.

(iv) The Ghaghara, the Gandak and the Kosi rise in the Nepal Himalaya. These rivers cause floods in parts of the Northern plains every year causing widespread damage to life and property whereas they enrich the soil for agricultural use.

(v) The Chambal, the Betwa and the Son come from peninsular uplands and have shorter course and do not carry much water in them.

Ans. The main features of the Brahmaputra river system are as mentioned below:

(i) Brahmaputra river rises in Tibet, east of Mansarovar Lake.

(ii) On reaching the Namcha Barwa (7757 m) it enters India in Arunachal Pradesh through a gorge. Here it is called the Dihang and joined by its tributaries to form the Brahmaputra in Assam.

(iii) The Brahmaputra has a braided channel in its entire length in Assam and forms many riverine islands.

(iv) In rainy season the river causes widespread devastation due to floods in Assam and Bangladesh.

(v) The river shifts its channel frequently.

Ans. The common features of the Narmada and Tapi rivers are as mentioned below:

(i) Both the rivers flow in rift valleys.

(ii) Both are the only long rivers which flow west

(iii) Both the rivers make estuaries.

Ans. (i) The Godavari is the largest peninsular river.

(ii) It rises from the slopes of the Western Ghats in the Nasik district of Maharashtra.

(iii) Its length is about 1,500 km

(iv) It drains into the Bay of Bengal

(v) Its drainage basin is the largest among the peninsular rivers. It covers parts of Maharashtra, Madhya Pradesh, Orissa and Andhra Pradesh.

(vi) Its tributaries are the Purna, the Wardha, the Pranhita, the Manjra, the Wainganga and the Penganga.

(vii) It is known as the ‘Dakshin Ganga’ due to its length and the area it covers.

Ans. Lakes are of great importance to human beings as given below:

(i) A lake helps to regulate the flow of a river.

(ii) During heavy rainfall, it prevents flooding.

(iii) During the dry season, it helps to maintain an even flow of water.

(iv) Lakes can be used for developing hydel power.

(v) Lakes moderate the climate of the surroundings.

(vi) Lakes maintain the aquatic ecosystem.

(vii) Lakes enhance natural beauty.

(viii) Lakes help in developing tourism.

(ix) Lakes provide recreation.

Ans. The causes for river pollution are as given below:

(i) The growing domestic, municipal, industrial and agricultural demand for water from rivers naturally affects the quality of water. As a result, more and more water is being drained out of the rivers reducing their volume.

(ii) A heavy load of untreated sewage and industrial effluents are emptied into the rivers. This affects not only the quality of water but also the self-cleansing capacity of the river.

(iii) Regarding the Ganga river’s pollution if given the adequate streamflow, the Ganga water is able to dilute and assimilate pollution loads within 20 km of large cities. But the increasing urbanization and industrialization do not allow it to happen and the pollution level increases.

Ans. (i) The river cleaning programme in the country was initiated with the launching of the Ganga Action Plan (GAP) in 1985.

(ii) The Ganga Action Plan was expanded to cover other rivers under the National River Conservation Plan (NRCP) in the year 1995.

(iii) the objective of the NRCP is to improve the water quality of the rivers, which are major water sources in the country through the implementation of pollution abatement work.

Ans. (i) According to the regulations of the Indus Water Treaty (1960), India can use only 20 percent of the total water carried by the Indus river system.

(ii) The water is used for irrigation in Punjab, Haryana and the Southern and the Western parts of Rajasthan.