Understanding Landforms

What is Landform? 

Why it is Important for Water Management?

Landforms are configurations of land in the form of morphological features such as hills, plains and pediments which are governed by some physical processes, and govern land use patterns. Understanding this aspect is important because occasionally due to regional geological conditions it shows the availability of local aquifers. 

What is Geomorphology?

Geomorphology is the study of the nature and history of landforms and the processes which create them. Landforms are produced by erosion or deposition, as rock and sediment is worn away by earth-surface processes like air, water & ice and transported & deposited at different localities. The different climatic environments produce different suites of landforms. As an example dunes are landforms characteristics of deserts, while drumlins are associated with glaciers Geomorphologist map the distribution of these landforms so as to understand better their occurrence.

What is the Geomorphic process?

• Endogenic – Processes which originate within the earth.
  
  • Volcanic eruption
  • Earthquake
  • Plate movement
  • Folding & Faulting
• Exogenic – originate on earth’s surface and within the atmosphere
  
  • Weathering & Erosion (Disintegration & Decomposition)
  • Deposition
  • Evaporations
• Physical agents responsible for different physical process
  
  • Water – river, ocean /marine, moisture, ice
  • Wind
  • Temperature
  • Slope and Gravity
• Classification of Landforms
• Based on shape
  
  • Linear – Scarps, valley, ridges
  • Areal – plains, pediments, hills
• Based on resultant processes
  
  • Erosional landforms – pediment zones
  • Depositional – alluvium plains, colluviums plains/fans
  • Tectonic land – Hills, uplifted rocky uplands

How to Identify and understand Landform?

This will involve field visit to the various areas to see and understand physiography and landform with following steps.

• The theory of landform followed by field exposure to show various landform. Exposure sites should be river channels, hilly terrains, coastal banks, tectonically disturbed areas where an expert will show various landforms originated due to respective processes.
• To teach this the trainer has to organise visits in all surroundings and all physiographic divisions and has to show various dominant landforms in the respective physiographic divisions and explain all the physical processes that played a role to craft landforms.
• After the field visits all trainees should divide into groups and be given a task to look at different aspects of landforms like slope, composition of material from size and shape point of view, location, responsible agent and the process for material/sediment generation.

Landform Map Preparation

To do this exercise toposheet will be used and then a basemap to identify various feature/landforms that exist in the study village/area. 

• To prepare a model of the landform sponge sheet is needed ; thickness of one sheet can consider as interval between two successive contour
• Cut these sponge sheets according to the contour shapes on basemap.
• Lay out each sheet as shown in basemap – use some adhesive to stick the sheet
• Once all sheets are arranged, use a canvas cloth to cover it.
• Spread wooden powder over cloth with adhesive coating to give a natural land texture.
• Draw different features as shown on the basemap such as river channels, settlement areas, roads and other aspects.
• If required, colour some of the features as per their appearance in the field.
• Place entire sponge model on plywood to prevent any damage.

Source : Empowering Village Communities for A Sustainable Water Future - A Resource Book for Jaldoots