Structure and Physiography

Correct Answer: (c) 10° Channel

Justification: The 10° Channel (so named because it lies along the 10° North latitude) separates the Andaman Islands (to the north) from the Nicobar Islands (to the south). The 11° Channel, on the other hand, separates the Little Andaman from Car Nicobar.

Correct Answer: (a) Nilgiri hills

Justification: Dodabeta (also spelled Doddabetta) is the highest peak of the Nilgiri Hills, standing at an elevation of 2,637 m. It is located in Tamil Nadu and is the highest point in the Western Ghats south of the Palakkad Gap.

Given: Lakshadweep is a group of islands located in the Arabian Sea.

Answer: A person travelling to Lakshadweep would prefer to travel from the Malabar Coast (Western Coastal Plain), specifically from ports such as Kochi (Cochin) in Kerala. This is because:
1. Lakshadweep lies in the Arabian Sea, which is on the western side of India.
2. The western coastal ports, especially Kochi, are the nearest and most well-connected to the Lakshadweep islands.
3. Regular ship and air services operate between Kochi and the Lakshadweep islands, making it the most convenient point of departure.

Given: India has diverse physiographic regions including high-altitude cold deserts.

Answer: A cold desert is found in the Ladakh region of the Union Territory of Jammu & Kashmir (and Ladakh). It lies to the east of the Great Himalayas and is characterised by extremely low temperatures, scanty rainfall, and sparse vegetation.

Important mountain ranges of this region include:
1. Karakoram Range — contains K2 (Godwin Austen), the second highest peak in the world.
2. Ladakh Range — runs between the Indus and Shyok rivers.
3. Zaskar Range — lies to the south of the Indus valley.
4. Kailash Range — located further east in the Trans-Himalayan zone.

Given: The Western Coastal Plain lies between the Western Ghats and the Arabian Sea.

Answer: The western coastal plain is devoid of any delta because of the following reasons:
1. The rivers flowing westward from the Western Ghats are short, swift, and have a steep gradient. They flow rapidly and do not carry much sediment load.
2. Due to their short length and fast speed, these rivers do not have enough time to deposit sediment at their mouths to form a delta.
3. The western coast is a submerged coastline (coastline of submergence), which means the sea has encroached upon the land, creating estuaries and lagoons rather than deltas.
4. The narrow continental shelf on the western side also does not favour delta formation.

Thus, instead of deltas, the western rivers form estuaries (e.g., the Narmada and Tapi rivers).

Given: India has two major groups of islands — Lakshadweep in the Arabian Sea and Andaman & Nicobar Islands in the Bay of Bengal.

Comparison of Island Groups:

| Feature | Lakshadweep (Arabian Sea) | Andaman & Nicobar (Bay of Bengal) |
|---|---|---|
| Location | Arabian Sea, west of Kerala coast | Bay of Bengal, southeast of Indian mainland |
| Number of islands | 36 islands (small) | 572 islands (large group) |
| Origin | Coral origin (atolls and coral reefs) | Elevated portions of submarine mountains; partly volcanic origin |
| Size | Very small; total area ~32 sq. km | Much larger; total area ~8,249 sq. km |
| Topography | Flat, low-lying | Hilly and undulating; Andaman group is hilly |
| Highest point | Very low elevation | Saddle Peak (737 m) in North Andaman |
| Separation | 10° Channel separates Andaman from Nicobar (not applicable here) | 10° Channel separates Andaman from Nicobar Islands |
| Vegetation | Tropical vegetation, coconut palms | Dense tropical rainforests |
| Volcanic activity | No active volcanoes | Barren Island has India's only active volcano |
| Administration | Union Territory; capital — Kavaratti | Union Territory; capital — Port Blair |

Conclusion: While Lakshadweep is a group of small coral islands with flat terrain, the Andaman and Nicobar Islands are larger, hilly, and of structural/volcanic origin. Both groups are ecologically sensitive and rich in biodiversity.

Given: River valley plains are formed by the depositional work of rivers over millions of years.

Important Geomorphological Features of River Valley Plains:

1. Alluvial Fan: When a river descends from mountains to plains, it deposits coarse sediment in a fan-shaped form called an alluvial fan.

2. Bhabar: A narrow belt (8–16 km wide) along the foothills of the Himalayas where rivers deposit pebbles and coarse material. Streams disappear underground here.

3. Terai: A marshy, swampy zone south of the Bhabar where underground streams re-emerge. It is covered with dense forests.

4. Bhangar: The older alluvial deposits forming upland terraces above the floodplain. The soil is less fertile and contains calcareous nodules called kankar.

5. Khadar: Newer, younger alluvial deposits found in the floodplains. It is renewed almost every year by floods and is very fertile.

6. Meanders: Sinuous, S-shaped curves formed by rivers on flat plains due to lateral erosion.

7. Ox-bow Lakes: Crescent-shaped lakes formed when a meander is cut off from the main river channel.

8. Floodplains: Low-lying areas on either side of the river that are periodically flooded and covered with fine alluvial deposits.

9. Delta: A triangular landform at the mouth of a river where it deposits sediment before meeting the sea (e.g., Sunderbans delta of the Ganga-Brahmaputra).

10. Levees: Natural embankments formed by deposition of sediment along the banks of a river during floods.

These features together make the river valley plains among the most fertile and densely populated regions in the world.

Given: The journey is along the course of the river Ganga, starting from Badrinath (in the Himalayas) and ending at the Sunderbans delta (in West Bengal).

Geomorphological Features Encountered:

1. Glacial Region (near Badrinath / Gangotri):
- The Ganga originates from the Gangotri Glacier (Bhagirathi). Near Badrinath (Alaknanda tributary), one encounters glaciers, moraines, U-shaped valleys, and hanging valleys.

2. Mountain/Upper Course (Himalayan region):
- V-shaped valleys carved by rapid river erosion.
- Gorges and canyons — the river cuts deep into the mountains.
- Waterfalls — where the river descends over hard rock.
- Rapids — turbulent stretches due to uneven rocky beds.

3. Foothills / Piedmont Zone (Haridwar region):
- Alluvial fans — coarse sediment deposited as the river slows down.
- Bhabar belt — porous, pebbly zone where streams sink underground.
- Terai — marshy zone where underground streams re-emerge; dense forests.

4. Upper Gangetic Plain (Haridwar to Allahabad):
- Bhangar — older alluvial terraces with kankar nodules.
- Khadar — newer fertile floodplain deposits.
- Meanders begin to form as the gradient decreases.

5. Middle Gangetic Plain (Allahabad to Varanasi/Patna):
- Well-developed meanders — the river winds extensively.
- Ox-bow lakes (locally called Tal or Jheel) — cut-off meanders.
- Floodplains — wide, flat, and very fertile.
- Natural levees along the river banks.

6. Lower Gangetic Plain (Bihar to West Bengal):
- Braided channels — the river splits into multiple channels.
- Chars — sandy islands formed in the middle of the river.
- Extensive floodplains with very fine alluvial deposits.

7. Delta Region (Sunderbans):
- Delta — the Ganga-Brahmaputra delta is the world's largest delta, known as the Sunderbans.
- Distributaries — the river splits into many channels (e.g., Hooghly, Padma, Meghna).
- Mangrove forests — the Sunderbans is famous for its mangrove ecosystem.
- Tidal flats and mudflats — formed by tidal action near the sea.
- Estuaries — where distributaries meet the Bay of Bengal.

Conclusion: The journey from Badrinath to the Sunderbans delta takes one through a complete sequence of fluvial geomorphological features — from erosional features in the mountains to depositional features in the plains and finally to the delta at the coast.

Note: This is a project/activity question requiring the use of an atlas. The following is a representative list of major Himalayan peaks arranged from west to east:

| S.No. | Peak | Height (approx.) | Location |
|---|---|---|---|
| 1 | Nanga Parbat | 8,126 m | Western Himalayas (Pakistan-administered Kashmir) |
| 2 | K2 (Godwin Austen) | 8,611 m | Karakoram Range, Ladakh |
| 3 | Nun Kun | 7,135 m | Zaskar Range, J&K |
| 4 | Badrinath Peak | 7,138 m | Garhwal Himalayas, Uttarakhand |
| 5 | Kedarnath Peak | 6,940 m | Garhwal Himalayas, Uttarakhand |
| 6 | Gangotri | 6,672 m | Garhwal Himalayas, Uttarakhand |
| 7 | Kamet | 7,756 m | Garhwal Himalayas, Uttarakhand |
| 8 | Nanda Devi | 7,817 m | Kumaon Himalayas, Uttarakhand |
| 9 | Trisul | 7,120 m | Kumaon Himalayas, Uttarakhand |
| 10 | Dhaulagiri | 8,167 m | Nepal Himalayas |
| 11 | Annapurna | 8,091 m | Nepal Himalayas |
| 12 | Mount Everest | 8,849 m | Nepal-Tibet border |
| 13 | Kanchenjunga | 8,586 m | Sikkim-Nepal border |
| 14 | Makalu | 8,485 m | Nepal-Tibet border |
| 15 | Namcha Barwa | 7,756 m | Eastern Himalayas, Arunachal Pradesh |

Students are advised to verify and supplement this list using a standard atlas.

Note: This is an activity-based question and the answer will vary depending on the student's state. A model answer for a state with diverse landforms (e.g., Uttar Pradesh) is given below. Students should adapt this to their own state.

Model Answer (Uttar Pradesh):

| Landform | Description | Major Economic Activity |
|---|---|---|
| Himalayan Foothills (Terai region) | Marshy, forested zone in northern UP (districts like Lakhimpur Kheri, Pilibhit) | Forestry, tea cultivation, elephant/tiger tourism, rice cultivation |
| Upper Gangetic Plain (Bhangar) | Older alluvial upland terraces | Wheat and sugarcane cultivation, dairy farming |
| Khadar / Floodplain | Newer alluvial deposits along the Ganga, Yamuna, Ghaghra | Intensive agriculture — rice, wheat, pulses, vegetables; fishing |
| Vindhyan Plateau (Bundelkhand) | Rocky, undulating terrain in southern UP | Quarrying (sandstone, granite), jowar/bajra cultivation, cattle rearing |

General Principle:
- Plains and fertile alluvial areas → Agriculture (wheat, rice, sugarcane), trade, and industry.
- Hilly and forested areas → Forestry, horticulture, tourism, and animal husbandry.
- Plateau regions → Mining, quarrying, and dry-land farming.

Students should draw a map of their state, mark the landforms, and write the corresponding economic activities based on local knowledge and atlas.