CBSE Class XI Geography Drainage System Concepts

Scroll down for PDF

CBSE Class XI Geography Drainage System Concepts. Learning the important concepts is very important for every student to get better marks in examinations. The concepts should be clear which will help in faster learning. The attached concepts made as per NCERT and CBSE pattern will help the student to understand the chapter and score better marks in the examinations.

DRAINAGE SYSTEM

The flow of water through well-defined channels is known as ‗drainage‘

The network of such channels is called a ‗drainage system‘.

The drainage pattern of an area is the outcome of the geological time period, nature and structure of rocks, topography, slope, amount of water flowing and the periodicity of the flow.

class_11_Geogeaphy_concept_21

Drainage system Important Drainage Patterns

(i) The drainage pattern resembling the branches of a tree is known as ―dendritic‖ the examples of which are the rivers of northern plain.

(ii) When the rivers originate from a hill and flow in all directions, the drainage pattern is Known as ‗radial‘. The rivers originating from the Amarkantak range present a good example of it.

(iii) When the primary tributaries of rivers flow parallel to each other and secondary tributaries join them at right angles, the pattern is known as ‗trellis‘.

(iv) When the rivers discharge their waters from all directions in a lake or depression, the pattern is know as ‗centripetal‘.

The boundary line separating one drainage basin from the other is known as the watershed.

The catchments of large rivers are called river basins while those of small rivulets and rills are often referred to as watersheds.

There is, however, a slight difference between a river basin and a watershed. Watersheds are small in area while the basins cover larger areas.

They are accepted as the most appropriate micro, meso or macro planning regions.

Indian drainage system may be divided on various bases.

On the basis of discharge of water

(orientations to the sea), it may be grouped into:

(i) the Arabian Sea drainage; and

(ii) the Bay of Bengal drainage.

class_11_Geogeaphy_concept_22

They are separated from eachother through the Delhi ridge, the Aravalis and the Sahyadris (water divide is shown by a line in Figure

3.1). river basin

77 per cent of the drainage area consisting of the Ganga, the Brahmaputra, the Mahanadi, the Krishna, etc. is oriented towards the Bay of Bengal 23 percent comprising the Indus, the Narmada, the Tapi,the Mahi and the Periyar systems discharge their waters in the Arabian Sea.

On the basis of the size of the watershed,

the drainage basins of India are grouped into three categories:

(i) Major river basins with more than 20,000 sq. km of catchment area. It includes 14 drainage basins such as the Ganga, the Brahmaputra, the Krishna, the Tapi, the Narmada, the Mahi, the Pennar, the Sabarmati, the Barak, etc.

(ii) Medium river basins with catchment area between 2,000-20,000 sq. km incorporating 44 river basins such as the Kalindi, the Periyar, the Meghna, etc.

(iii) Minor river basins with catchment area of less than 2,000 sq. km include fairly good number of rivers flowing in the area of low rainfall.                                                                                                                                                      North Indian rivers are originating from Himalayas peninsular rivers are originating from Western ghats

The Narmada and Tapi are two large rivers which are exceptions originating form central highlands.

the Indian drainage may also be classified into the Himalayan drainage and the Peninsular drainage.

THE HIMALAYAN DRAINAGE

1. The Himalayan drainage system has a long geological history.

2. the important rivers are Ganga, the Indus and the Brahmaputra rivers.

3. Since these are fed both by melting of snow and precipitation, rivers of this system are perennial.

4 .rivers form giant gorges V-shaped valleys, rapids and waterfalls in their mountainous course.

5. While entering the plains, they form depositional features like flat valleys, ox-bow lakes, flood plains,

EVOLUTION OF THE HIMALAYAN DRAINAGE

1.Geologists believe that a mighty river called Shiwalik or Indo-Brahma traversed the entire longitudinal extent of the Himalaya from Assam to Punjab and onwards to Sind, and finally discharged into the Gulf of Sind near lower Punjab during the Miocene period some 5-24 million years ago

2. The remarkable continuity of the Shiwalik and its lacustrine origin and alluvial deposits consisting of sands, silt, clay, boulders and conglomerates support this viewpoint. in due course of time Indo– Brahma river was dismembered into three main

drainage systems:

(i) the Indus and its five tributaries in the western part;

(ii) the Ganga and its Himalayan tributaries in the central part; and

(iii) the stretch of the Brahmaputra in Assam and its Himalayan tributaries in the eastern part. The dismemberment was probably due to the Pleistocene upheaval in the western Himalayas, including the uplift of the Potwar Plateau (Delhi Ridge), which acted as the water divide between the Indus and Ganga drainage systems. Likewise, the down thrusting of the Malda gap area between the Rajmahal hills and the Meghalaya plateau during the mid-pleistocene period, diverted the Ganga and the Brahmaputra systems to flow Towards the Bay of Bengal.

THE RIVER SYSTEMSOFTHEHIMALAYAN DRAINAGE

The Indus System

1.It is one of the largest river basins of the world, covering an area of 11,65,000 sq. km (in India it is 321, 289 sq. km and a total length of 2,880 km (in India 1,114 km).

2. The Indus also known as the Sindhu, is the westernmost of the Himalayan rivers in India.

3. It originates from a glacier near Bokhar Chu (31°15' N latitude and 81°40' E longitude) in the Tibetan region at an altitude of 4,164 m in the Kailash Mountain range.

4. In Tibet, it is known as ‗Singi Khamban; or Lion‘s mouth. After flowing in the northwest direction between the Ladakh and Zaskar ranges, it passes through Ladakh and Baltistan.

5.It cuts across the Ladakh range, forming a spectacular gorge near Gilgit in Jammu and Kashmir.

6. It enters into Pakistan near Chillar in the Dardistan region. Find out the area known as Dardistan.

7. tributaries such as the Shyok, the Gilgit, theZaskar, the Hunza, the Nubra, the Shigar, the Gasting and the Dras.

9. It finally emerges out ofthe hills near Attock where it receives the Kabul river on its right bank.

10.The other important tributaries joining the right bank of the Indus are the Khurram, the Tochi, the Gomal, the Viboa and the Sangar. They all originate in the Sulaiman ranges.

11. The river flows southward and receives ‗Panjnad‘ a little above Mithankot. The Panjnad is the name given to the five rivers of Punjab, namely the Satluj, the Beas, the Ravi, the Chenab and the Jhelum.It finally discharges into the Arabian Sea, east of Karachi. The Indus flows in India only through the Leh district in Jammu and Kashmir.

The Ganga System

1. The Ganga is the most important river of India both from the point of view of its basin and cultural significance.

2. It rises in the Gangotri glacier near Gaumukh (3,900 m) in the Uttarkashi district of Uttarakhand. 

Please click the link below to download pdf file for CBSE Class XI Geography Drainage System Concepts.

Tags: 


Click on the text For more study material for Geography please click here - Geography

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

Sample Papers for Class 12 Boards 2020

CBSE has released the final sample papers for the class 12 boards exams as per the new pattern as per which the question papers are expected to come in the 2020 board exams for class 12. The sample papers have been for class 12 for all subjects along with the suggested...

CBSE and Microsoft join hands to build capacity for AI learning for schools

Central Board of Secondary Education and Microsoft join hands to build capacity for AI learning for schools : The officials from the Central Board of Secondary Education have announced that they have partnered with Microsoft India to conduct several capacity building...

TIPS: Study habits for success

Being a student is fairly a difficult job. Alongside maintaining your curricular as well as extra-curricular activities adds more to it. Performance in academics is one of the major concerns. Every parent now tries to get their children more indulged in studies. Need...

NCERT NTSE Admit Card 2020 released - know more

Introduction: NTSE 2020 National Talent search examination is conducted by NCERT to take out the students who excel in science. It is organized to measure and let the students with talent outshine in their coming future. This talent search exam is taken in 2 stages....

Extension of dates by CBSE for Single Girl Child Merit (SGC) scholarship

CBSE has announced to extend dates for SGC scholarship. Previously the dates to submit the SGC scholarship form were 18 October 2019. Now dates have shifted. For online submission, the last date is 31st October. Whereas date for submission of hard copies of renewal...

IBM to Set AI Curriculum for CBSE Class IX to XII

The Central Board of Secondary Education has tied up with IBM to develop a course of Artificial Intelligence in the CBSE curriculum. Now CBSE is going to introduce Artificial Intelligence as an elective subject for class 9 to 12th. The CBSE has taken this decision to...

×
Studies Today