Drainage System | Geography for UPSC 2026 (Pre & Mains) PDF Download

 Page 1


 
 DRAINAGE SYSTEM 
BASIC TERMINOLOGIES: 
The flow of water through well-defined channels is known as drainage and 
the network of such channels is known as drainage system. 
 
 
The drainage pattern of an area is the result of the geological time period, 
nature, and structure of rocks, topography, slope, etc.  
 
 
 
 
 
Page 2


 
 DRAINAGE SYSTEM 
BASIC TERMINOLOGIES: 
The flow of water through well-defined channels is known as drainage and 
the network of such channels is known as drainage system. 
 
 
The drainage pattern of an area is the result of the geological time period, 
nature, and structure of rocks, topography, slope, etc.  
 
 
 
 
 
 
RIVER BASIN 
A river basin is the portion of land drained by a river and its tributaries.  
 
 
 
 
 
 
 
 
 
 
Page 3


 
 DRAINAGE SYSTEM 
BASIC TERMINOLOGIES: 
The flow of water through well-defined channels is known as drainage and 
the network of such channels is known as drainage system. 
 
 
The drainage pattern of an area is the result of the geological time period, 
nature, and structure of rocks, topography, slope, etc.  
 
 
 
 
 
 
RIVER BASIN 
A river basin is the portion of land drained by a river and its tributaries.  
 
 
 
 
 
 
 
 
 
 
 
WATERSHED: 
A watershed is simply the area of land that catches rain and snow and 
drains or seeps into a marsh, stream, river, lake or groundwater. 
 
Both river basins and watersheds are areas of land that drain to a 
particular water body, such as a lake, stream, river or estuary. 
 In a river basin, all the water drains to a large river. The term watershed is 
used to describe a smaller area of land that drains to a smaller stream, lake 
or wetland. There are many smaller watersheds within a river basin. 
 
 
 
 
 
 
 
 
 
Page 4


 
 DRAINAGE SYSTEM 
BASIC TERMINOLOGIES: 
The flow of water through well-defined channels is known as drainage and 
the network of such channels is known as drainage system. 
 
 
The drainage pattern of an area is the result of the geological time period, 
nature, and structure of rocks, topography, slope, etc.  
 
 
 
 
 
 
RIVER BASIN 
A river basin is the portion of land drained by a river and its tributaries.  
 
 
 
 
 
 
 
 
 
 
 
WATERSHED: 
A watershed is simply the area of land that catches rain and snow and 
drains or seeps into a marsh, stream, river, lake or groundwater. 
 
Both river basins and watersheds are areas of land that drain to a 
particular water body, such as a lake, stream, river or estuary. 
 In a river basin, all the water drains to a large river. The term watershed is 
used to describe a smaller area of land that drains to a smaller stream, lake 
or wetland. There are many smaller watersheds within a river basin. 
 
 
 
 
 
 
 
 
 
 
DISTRIBUTARY vs TRIBUTARY 
Distributary is a strean /river which flows away from a large river.It 
decreases the volume of water of the main river. 
 
 
 
 
 
 
 
 
 
 
 
 
 
Page 5


 
 DRAINAGE SYSTEM 
BASIC TERMINOLOGIES: 
The flow of water through well-defined channels is known as drainage and 
the network of such channels is known as drainage system. 
 
 
The drainage pattern of an area is the result of the geological time period, 
nature, and structure of rocks, topography, slope, etc.  
 
 
 
 
 
 
RIVER BASIN 
A river basin is the portion of land drained by a river and its tributaries.  
 
 
 
 
 
 
 
 
 
 
 
WATERSHED: 
A watershed is simply the area of land that catches rain and snow and 
drains or seeps into a marsh, stream, river, lake or groundwater. 
 
Both river basins and watersheds are areas of land that drain to a 
particular water body, such as a lake, stream, river or estuary. 
 In a river basin, all the water drains to a large river. The term watershed is 
used to describe a smaller area of land that drains to a smaller stream, lake 
or wetland. There are many smaller watersheds within a river basin. 
 
 
 
 
 
 
 
 
 
 
DISTRIBUTARY vs TRIBUTARY 
Distributary is a strean /river which flows away from a large river.It 
decreases the volume of water of the main river. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
DRAINAGE PATTERNS: 
Consequent Streams: Those streams whose courses are the direct 
consequence of the initial topography are called consequent streams. 
Subsequent Streams: These are developed after the master consequent. 
Obsequent streams: These flow in opposite direction to the master 
consequent. 
Resequent Streams: A resequent stream flows in the same direction as that 
of the initial consequent stream, but which develops in response to a new 
base level formed due to inversion of relief.