Physical Geography: Geomorphology, Climatology and Oceanography
Physical Geography for this elective brings together geomorphology, climatology and oceanography. Questions test process understanding, landform identification and explanation of Odisha and Bay of Bengal examples rather than isolated definitions.
Core rules and concepts
- Endogenic processes such as plate movement, volcanism and folding build relief; exogenic processes such as weathering, erosion, transport and deposition sculpt it.
- Weathering is in-situ breakdown; erosion involves removal and transport. A V-shaped valley indicates vertical fluvial incision; a broad floodplain indicates lateral erosion and deposition.
- The normal lapse rate is about 6.5°C per 1,000 m. Pressure belts shift with the apparent movement of the Sun; Coriolis deflection is to the right in the Northern Hemisphere.
- The Indian monsoon is a seasonal reversal of winds: south-west monsoon in June–September, north-east monsoon in October–December. Odisha receives most rain from the Bay of Bengal branch and cyclonic depressions.
- Ocean salinity averages about 35 ppt. The Bay of Bengal is fresher than the Arabian Sea because of heavy river discharge and rainfall. Currents and tides are driven by winds, density differences and gravitational pull.
Worked example
A hill station at 1,200 m records 24°C. Using the normal lapse rate, sea-level temperature = 24 + (1.2 × 6.5) = 31.8°C. Reasoning: temperature normally falls with height, so descending means adding heat. The answer is an average; local inversions can reverse it.
Traps that cost marks
- Calling weathering erosion without transport.
- Placing the south-west monsoon in winter.
- Saying Chilika is a freshwater lake; it is a brackish lagoon connected to the sea.
- Assuming the Mahanadi delta is a simple triangle; waves, tides and channels shape it.