The Himalayan Drainage | Geography for UPSC 2024 (Pre & Mains) PDF Download

 Page 1


 
THE HIMALAYAN DRAINAGE  
  
It mainly includes the Gangs, the Indus and the Brahmaputra river 
basins.  
Since these are fed both by melting of snow and precipitation, rivers of 
this system are perennial.  
These rivers pass through the giant gorges carved out by the erosional 
activity carried on simultaneously with the uplift of the Himalayas.  
Besides deep gorges, these rivers also form Vshaped valleys, rapids and 
waterfalls in their mountainous Course. While entering the plains, they 
form depositional features like flat valleys, oxbow lakes. flood plains. 
braided channels, and deltas near the river mouth.  
In the Himalayan reaches, the course of these rivers is highly tortuous, but 
over the plains they display a strong meandering tendency and shift their 
courses frequently.  
for example, River Kosi, also known as the 'Sorrow of Bihar' has been 
notorious for frequently changing its course.  The Kosi brings huge 
quantity of sediments from its upper reaches and deposits it in the 
plains. The course gets blocked, and consequently, the river changes its 
course. 
 
Page 2


 
THE HIMALAYAN DRAINAGE  
  
It mainly includes the Gangs, the Indus and the Brahmaputra river 
basins.  
Since these are fed both by melting of snow and precipitation, rivers of 
this system are perennial.  
These rivers pass through the giant gorges carved out by the erosional 
activity carried on simultaneously with the uplift of the Himalayas.  
Besides deep gorges, these rivers also form Vshaped valleys, rapids and 
waterfalls in their mountainous Course. While entering the plains, they 
form depositional features like flat valleys, oxbow lakes. flood plains. 
braided channels, and deltas near the river mouth.  
In the Himalayan reaches, the course of these rivers is highly tortuous, but 
over the plains they display a strong meandering tendency and shift their 
courses frequently.  
for example, River Kosi, also known as the 'Sorrow of Bihar' has been 
notorious for frequently changing its course.  The Kosi brings huge 
quantity of sediments from its upper reaches and deposits it in the 
plains. The course gets blocked, and consequently, the river changes its 
course. 
 
 
EVOLUTION OF THE HIMALAYAN DRAINAGE  
There are difference of opinion about the evolution of the Himalayan rivers 
However, geologists believe that a mighty river called Shiwalik or 
Indo- Brahma traversed the entire longitudinal extant of the Himalaya 
from Assam to Punjab and onwards to Sind.  
 
If Is opined that in due course of time Indo- Brahma river was 
dismembered into three main drainage systems  
- The Indus and its five tributaries in the western part  
- The Gangs and its Himalayan tributaries in the central part  
- The stretch of the Brahmaputra in Assam and its Himalayan 
tributaries in the eastern part  
 
REASON: 
The dismemberment was probably due to the Pleistocene upheaval in 
the western Himalayas. including the uplift Of the Potwar Plateau 
along the Delhi Ridge which acted as the water divide between the 
Indus and Gangs drainage systems  
 
Page 3


 
THE HIMALAYAN DRAINAGE  
  
It mainly includes the Gangs, the Indus and the Brahmaputra river 
basins.  
Since these are fed both by melting of snow and precipitation, rivers of 
this system are perennial.  
These rivers pass through the giant gorges carved out by the erosional 
activity carried on simultaneously with the uplift of the Himalayas.  
Besides deep gorges, these rivers also form Vshaped valleys, rapids and 
waterfalls in their mountainous Course. While entering the plains, they 
form depositional features like flat valleys, oxbow lakes. flood plains. 
braided channels, and deltas near the river mouth.  
In the Himalayan reaches, the course of these rivers is highly tortuous, but 
over the plains they display a strong meandering tendency and shift their 
courses frequently.  
for example, River Kosi, also known as the 'Sorrow of Bihar' has been 
notorious for frequently changing its course.  The Kosi brings huge 
quantity of sediments from its upper reaches and deposits it in the 
plains. The course gets blocked, and consequently, the river changes its 
course. 
 
 
EVOLUTION OF THE HIMALAYAN DRAINAGE  
There are difference of opinion about the evolution of the Himalayan rivers 
However, geologists believe that a mighty river called Shiwalik or 
Indo- Brahma traversed the entire longitudinal extant of the Himalaya 
from Assam to Punjab and onwards to Sind.  
 
If Is opined that in due course of time Indo- Brahma river was 
dismembered into three main drainage systems  
- The Indus and its five tributaries in the western part  
- The Gangs and its Himalayan tributaries in the central part  
- The stretch of the Brahmaputra in Assam and its Himalayan 
tributaries in the eastern part  
 
REASON: 
The dismemberment was probably due to the Pleistocene upheaval in 
the western Himalayas. including the uplift Of the Potwar Plateau 
along the Delhi Ridge which acted as the water divide between the 
Indus and Gangs 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 Gangs and the Brahmaputra systems to flow 
towards the Bay of Bengal 
 
  
 
 
 
 
 
 
 
 
 
 
 
Page 4


 
THE HIMALAYAN DRAINAGE  
  
It mainly includes the Gangs, the Indus and the Brahmaputra river 
basins.  
Since these are fed both by melting of snow and precipitation, rivers of 
this system are perennial.  
These rivers pass through the giant gorges carved out by the erosional 
activity carried on simultaneously with the uplift of the Himalayas.  
Besides deep gorges, these rivers also form Vshaped valleys, rapids and 
waterfalls in their mountainous Course. While entering the plains, they 
form depositional features like flat valleys, oxbow lakes. flood plains. 
braided channels, and deltas near the river mouth.  
In the Himalayan reaches, the course of these rivers is highly tortuous, but 
over the plains they display a strong meandering tendency and shift their 
courses frequently.  
for example, River Kosi, also known as the 'Sorrow of Bihar' has been 
notorious for frequently changing its course.  The Kosi brings huge 
quantity of sediments from its upper reaches and deposits it in the 
plains. The course gets blocked, and consequently, the river changes its 
course. 
 
 
EVOLUTION OF THE HIMALAYAN DRAINAGE  
There are difference of opinion about the evolution of the Himalayan rivers 
However, geologists believe that a mighty river called Shiwalik or 
Indo- Brahma traversed the entire longitudinal extant of the Himalaya 
from Assam to Punjab and onwards to Sind.  
 
If Is opined that in due course of time Indo- Brahma river was 
dismembered into three main drainage systems  
- The Indus and its five tributaries in the western part  
- The Gangs and its Himalayan tributaries in the central part  
- The stretch of the Brahmaputra in Assam and its Himalayan 
tributaries in the eastern part  
 
REASON: 
The dismemberment was probably due to the Pleistocene upheaval in 
the western Himalayas. including the uplift Of the Potwar Plateau 
along the Delhi Ridge which acted as the water divide between the 
Indus and Gangs 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 Gangs and the Brahmaputra systems to flow 
towards the Bay of Bengal 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
MEANING ON MAP: 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Page 5


 
THE HIMALAYAN DRAINAGE  
  
It mainly includes the Gangs, the Indus and the Brahmaputra river 
basins.  
Since these are fed both by melting of snow and precipitation, rivers of 
this system are perennial.  
These rivers pass through the giant gorges carved out by the erosional 
activity carried on simultaneously with the uplift of the Himalayas.  
Besides deep gorges, these rivers also form Vshaped valleys, rapids and 
waterfalls in their mountainous Course. While entering the plains, they 
form depositional features like flat valleys, oxbow lakes. flood plains. 
braided channels, and deltas near the river mouth.  
In the Himalayan reaches, the course of these rivers is highly tortuous, but 
over the plains they display a strong meandering tendency and shift their 
courses frequently.  
for example, River Kosi, also known as the 'Sorrow of Bihar' has been 
notorious for frequently changing its course.  The Kosi brings huge 
quantity of sediments from its upper reaches and deposits it in the 
plains. The course gets blocked, and consequently, the river changes its 
course. 
 
 
EVOLUTION OF THE HIMALAYAN DRAINAGE  
There are difference of opinion about the evolution of the Himalayan rivers 
However, geologists believe that a mighty river called Shiwalik or 
Indo- Brahma traversed the entire longitudinal extant of the Himalaya 
from Assam to Punjab and onwards to Sind.  
 
If Is opined that in due course of time Indo- Brahma river was 
dismembered into three main drainage systems  
- The Indus and its five tributaries in the western part  
- The Gangs and its Himalayan tributaries in the central part  
- The stretch of the Brahmaputra in Assam and its Himalayan 
tributaries in the eastern part  
 
REASON: 
The dismemberment was probably due to the Pleistocene upheaval in 
the western Himalayas. including the uplift Of the Potwar Plateau 
along the Delhi Ridge which acted as the water divide between the 
Indus and Gangs 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 Gangs and the Brahmaputra systems to flow 
towards the Bay of Bengal 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
MEANING ON MAP: 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
THE EVOLUTION OF PENINSULAR DRAINAGE SYSTEM 
The Peninsular drainage system is older than the Himalayan one.  
Peninsular rivers are characterised by fixed course. absence of 
meanders and nonperennial flow of water . 
NOTE: 
The Chambal. the Sind. the Betwa. the Ken, the Son, originating in the 
northern part of the Peninsula belong to the Gangs over system  
 
Three major geological events in the distant past have shaped the present 
drainage systems of Peninsular India:  
(i) Subsidence of the western flank of the Peninsula leading to its 
submergence below the sea during the early tertiary period. 
Generally, it has disturbed the symmetrical plan of the river on either 
side of the original watershed. 
 
 
 
(ii)  Upheaval of the Himalayas when the northern flank of the 
Peninsular block was subjected to subsidence and the consequent 
trough faulting.  
The Narmada and The Tapi flow in trough faults and fill the 
original cracks with their detritus materials.  Hence, there is a 
lack of alluvial and deltaic deposits in these rivers.