Geomorphology for CSIR NET Earth Science: Landforms, Processes and PYQ Strategy

Geomorphology asks a simple question in many forms: which process made this landform? CSIR NET Earth Science questions on this unit are often diagram- or description-based, so understanding the processes is far more useful than memorising long lists of landform names.

What the syllabus covers

• Weathering and mass wasting: physical, chemical and biological weathering; soil formation; landslides, creep and slope stability.
• Fluvial geomorphology: drainage patterns, stream order, river profiles, base level, meanders, braided channels, deltas and alluvial fans.
• Glacial geomorphology: glacier types and movement, erosional landforms (cirques, U-shaped valleys, arêtes) and depositional landforms (moraines, drumlins, eskers).
• Aeolian geomorphology: wind erosion and transport, dune types (barchan, transverse, longitudinal, star).
• Coastal geomorphology: waves, longshore drift, beaches, spits, cliffs and sea-level change.
• Karst and tectonic geomorphology: limestone dissolution landforms; landforms produced by faulting and uplift.
• Methods: morphometric analysis, remote sensing and topographic map interpretation.

High-yield topics

1. Drainage patterns and what they reveal: dendritic (uniform rock), trellis (folded strata), radial (domes and volcanoes), rectangular (jointed rock), annular (eroded domes).
2. Stream order and morphometry: Strahler ordering, bifurcation ratio and drainage density.
3. River behaviour: how base-level change causes incision or aggradation, and how this produces river terraces.
4. Glacial versus fluvial valleys: U-shaped versus V-shaped, hanging valleys and misfit streams.
5. Dune types and the wind and sand-supply conditions that form each one.

Concepts examiners love

• Davis versus Penck: the cycle of erosion compared with ideas about slope development under ongoing uplift.
• Hjulström diagram: the relationship between flow velocity and the erosion, transport and deposition of different grain sizes. Fine clay needs a surprisingly high velocity to erode.
• Climatic geomorphology: why the same rock forms different landforms in humid and arid climates.
• Himalayan and Indian examples: river terraces, glacial landforms and the Thar Desert.

How to revise in 10 days

• Days 1–2: weathering, mass wasting and soils.
• Days 3–5: fluvial geomorphology and morphometry, the largest share of questions.
• Days 6–7: glacial and aeolian landforms.
• Day 8: coastal and karst landforms.
• Days 9–10: tectonic geomorphology and map interpretation, then a timed set of previous year questions.

Common mistakes

• Learning landforms without the process that formed them.
• Mixing up drainage patterns that look similar, such as trellis and rectangular.
• Misreading the Hjulström diagram’s erosion curve for fine sediment.