By going through these Maharashtra State Board Class 11 Geography Notes Chapter 3 Agents of Erosion students can recall all the concepts quickly.

Maharashtra State Board Class 11 Geography Notes Chapter 3 Agents of Erosion

Agents of Erosion:

  1. Running Water(River)
  2. Sea Waves
  3. Wind
  4. Glaciers
  5. Ground Water

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion 1

→ Agents of erosion cause various processes when they pick up, move and deposit rock particles. These processes lead to erosional and depositional landforms.

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion

Processes of Erosion:

River-

  • Attrition
  • Solution
  • Downcutting
  • Drilling
  • Headward erosion
  • Lateral erosion

Sea Waves-

  • Abrasion
  • Attrition
  • Solution
  • Lateral erosion

Wind-

  • Abrasion
  • Attrition
  • Deflation

Glacier-

  • Plucking
  • Abrasion
  • Downcutting
  • Headward erosion
  • Lateral erosion

Ground Water-
Solution

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion 2

Processes of Transportation :

  • Traction : The material acquired by the agents is transported by rolling, pushing and dragging along the surface.
  • Saltation : Often the rock materials move forward by leaps and bounds through this process.
  • Suspension : Fine light material is carried along with water or air in the upper layer.
  • Solution : The material is carried in water in a dissolved state.

Processes of Transportation :

River-

  • Traction
  • Saltation
  • Suspension
  • Solution

Sea Waves-

  • Traction
  • Saltation
  • Suspension
  • Solution

Wind-

  • Traction
  • Saltation
  • Suspension

Glacier-
Traction

Ground Water-
Solution

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion 3

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion

Processes of Erosion :

  • Plucking : The process by which moving ice exerts pressure on majority portion of rocks on bed or along the bank.
  • Abrasion : It involves the scratching and polishing of the surface or bedrock by the particles which are moving onto it.
  • Attrition: It is when rocks and pebbles bump into each other and break up into smaller fragments.
  • Solution : It is when certain types of rocks get eroded as a result of acids in the sea or river water.
  • Deflation : The particles which are loosened on the surface are blown away by the wind.
  • Drilling : Bedload moves along the running water. As and when this flow encounters an obstacle due to relief on the bed or joints in the bed, the flow tends to develop a circular pattern. This leads to development of a whirl.
  • Downcutting : Also called downward erosion is a process of hydraulic action that deepens the channel of a stream or valley by removing material from the stream’s bed or the valley’s floor.
  • Headward erosion : It is the backward erosion by river in the source region.
  • Lateral erosion : It is the erosion that occurs on the sides of valleys of a river or glacier.

Agents of erosion and landforms :
Factor affecting formation of landforms – climate, type of rocks, intensity of erosion, slope of land and obstacles.

River as an Agent of Erosion:

  1. Erosional Features
  2. Depositional Features

1. Erosional Features

  • Gorges and Canyons
  • V-shaped valley
  • Cliffs
  • Waterfalls
  • Rapids
  • Potholes

2. Depositional Features

  • Alluvial fans
  • Meanders
  • Oxbow lakes
  • Flood plains
  • Natural levees
  • Islands
  • Deltas
  • Estuaries

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion 4

Sea Water as an Agent of Erosion:

Erosional Features-

  • Sea cliffs
  • Sea caves
  • Sea arch
  • Sea stack
  • Wave cut platforms

Depositional Features-

  • Sea beach
  • Lagoon
  • Headlands
  • Sand spits

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion 5

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion

Conditions necessary for wind erosion :

  • Aridity – In such areas, rate of evaporation is greater than rate of precipitation.
  • Sparse vegetation cores or absence of trees.
  • Presence of dry loose materials at the surface.
  • A wind velocity high enough to pick up and move sediments.

Wind as an agent of Erosion:

  1. Erosional Features
  2. Depositional Feature

1. Erosional Features:

  • Deflation Hallows
  • Ventifacts
  • Mushroom Rocks
  • Yardangs

2. Depositional Feature

  • Loess
  • Barchans
  • Sand Dunes

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion 6

Karst topography needs three important factors to develop:

  1. Carbon dioxide
  2. Active movement of underground water
  3. Joints

Work of Ground Water:

  1. Erosional Features
  2. Depositional Features

1. Erosional Features

  • Sink Holes
  • Caves

2. Depositional Features:

  • Stalactite
  • Stalagmite
  • Columnor Pillars

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion 7

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion

Work of Glaciers:

  1. Erosional Features
  2. De positional Features

1. Erosional Features:

  • Roche mountonnees
  • Cirque
  • Arete
  • Horn, Matterhorn
  • U-Shaped valley, hanging valley

2. De positional Features:

  • Drumlin
  • Eskers
  • Erratic rock

Maharashtra Board Class 11 Geography Notes Chapter 3 Agents of Erosion 8