Structure and Physiography
EXERCISES
1. Choose the right answer from the four alternatives given below.
(i) Which one of the water bodies separates the Andaman from the Nicobar?
(a) 11° Channel (c) 10°Channel
(b) Gulf of Mannar (d) Andaman Sea
Ans: (c) 10°Channel.
(ii) On which of the following hill range is the ‘Dodabeta’ peak situated?
(a) Nilgiri hills (c) Cardamom hills
(b) Anaimalai hills (d) Nallamala hills
Ans: (a) Nilgiri hills.
2. Answer the following questions in about 30 words.
(i) If a person is to travel to Lakshadweep, from which coastal plain does he prefer and why?
Ans: Malabar Coast, near Kochi in Kerala. It's the closest mainland point to Lakshadweep, offering convenient access via flights and ships. Other coasts involve longer, expensive journeys.
(ii) Where in India will you find a cold desert? Name some important ranges of this region.
Ans: The cold desert of India is nestled within the mighty Himalayas in Ladakh, Jammu and Kashmir state.
Two major mountain ranges frame this breathtaking region:
*Karakoram Range: Home to K
(iii) Why is the western coastal plain is devoid of any delta?
Ans: Steep rivers, narrow plain & strong ocean currents hinder sediment build-up, preventing delta formation on India's west coast.
3. Answer the following questions in not more than 125 words.
(i) Make a comparison of the island groups of the Arabian Sea and the Bay of Bengal.
Ans: Island Gems of the Arabian Sea and Bay of Bengal: A Quick Comparison
Location & Size:
*Arabian Sea: Lakshadweep Islands, a string of 36 coral atolls scattered off India's southwest coast. Total area: 32 sq km.
*Bay of Bengal: Andaman & Nicobar Islands, two archipelagos with 572 islands. Andaman group closer to mainland India, Nicobars farther southeast. Total area: 8,249 sq km.
(ii) What are the important geomorphological features found in the river valley plains?
Ans: River valley plains, sculpted by the erosive and depositional forces of rivers, boast a diverse array of geomorphological features. Here are some key ones:
1. Floodplains: Flat, fertile lands flanking the river channel, built from sediment deposited during floods.
2. River meanders: Winding bends in the river channel caused by erosion and deposition, creating horseshoe-shaped landforms.
3. Oxbow lakes: Cresent-shaped lakes formed when meanders are cut off due to changes in the river course.
4. River terraces: Elevated remnants of former floodplains, marking past river levels.
5. Deltas: Triangular landforms at river mouths, where sediment accumulates as the river slows down and spreads out.
6. Alluvial fans: Fan-shaped deposits formed where mountain streams lose velocity and spread out onto flatter plains.
These features not only influence landform and soil fertility but also shape human settlements, agriculture, and flood risks. Understanding these geomorphological wonders helps us appreciate the dynamic interplay between rivers and the landscapes they create.
(iii) If you move from Badrinath to Sunderbans delta along the course of the river Ganga, what major geomorphological features will you come across?
Ans: Journeying alongside the mighty Ganga from its Himalayan birth in Badrinath to the sprawling Sundarbans delta is a mesmerizing trek through diverse geomorphological wonders. Here's a glimpse of what awaits you:
1. Mountain Valleys: In the early stages, the Ganga carves its path through steep, V-shaped valleys carved by glacial erosion. Think towering peaks, rushing rapids, and dramatic drops in elevation.
2. Gorges and Canyons: As the river descends, it cuts through resistant rock formations, creating deep, narrow gorges with sheer cliffs and plunging waterfalls. Imagine the thrill of witnessing the Ganga's fury at places like Rishikesh and Haridwar.
3. River Terraces: Further downstream, the gradient eases, and the Ganga deposits sediments along its banks, forming elevated plains called river terraces. These fertile lands support agriculture and human settlements.
4. Floodplains: As the river enters the vast Indo-Gangetic Plain, it meanders through expansive floodplains. These flat, fertile lands, enriched by regular floods, are the lifeblood of agriculture in India.
5. Oxbow Lakes: Abandoned meanders of the Ganga transform into crescent-shaped oxbow lakes, adding a touch of tranquility to the landscape. These havens for flora and fauna provide scenic spots for recreation and birdwatching.
6. Sundarbans Delta: Finally, the Ganga reaches its majestic culmination in the Sundarbans delta, a maze of interlacing channels, mangrove forests, and mudflats teeming with life. This UNESCO World Heritage Site is a testament to the river's immense power and ecological significance.
So, prepare to be awestruck by the Ganga's journey, as it sculpts and shapes the land, leaving behind a legacy of breathtaking geomorphological wonders. Each feature tells a story of erosion, deposition, and the relentless flow of time, etching itself into the very fabric of India's landscape.
Project/Activity
(i) Make a list of major Himalayan peaks from the west to the east with the
help of an atlas.
(ii) Identify the major landforms of your state and analyse the major economic
activity practised by the people in each landform.
