Glossary and Important Information
1. Tarai Zone: It is a Zone next to the bhabar which is wet and marshy. It has a thick forest cover and a variety of wildlife.
2. Water divide: The upland that separates the flow of two rivers or river system.
3. Delta: It is a triangular deposition of sediment at the mouth of a river. The river become slow at the mouth of the sea, so mud and silt settle down and from the delta.
4. Estuary: It is a narrow deep valley at the mouth of a river where currents or tides are strong or the current of the river itself is swift.
5. Tributary: A river which joins the main river and increase the volume of water.
6. Plate Tectonic: The scientific concept which explains the movements of the different plates of the crust of the earth.
7. Gondwana land: A major portion of the crust which once incorporated Australia, Peninsular India south Africa and south America.
Fig. Fabled continent Gondwana Land
8. Tethys Sea: A narrow sea with a sinking bottom lying between Gondwana land in the south and Angara land in the north.
9. Flood Plain: A plain formed by the sediment deposited by the rivers years after year.
10. Bar: A deposit of sand or mud in the river channel.
11. Levees: An elevated bank flanking the channel of a river and standing above the level of the flood plains.
12. Lagoon: A salt water lake separated from the sea by the sandbars.
13. Glacier: Slow moving rivers of snow & ice.
14. Pass: A gap in mountain range providing a natural route across.
15. Alluvial Plains: Flat low lying lands made of the alluvium.
16. Diverging plate: Plates which are moving away form each other.
17. Converging Plate: Plates which are coming together.
18. Pernnial Rivers: Rivers which flow through out the year.
19. Fold mountain: The fold mountains formed during the most recent major phase of folding in the earth’s crust.
20. Coral Polyps: Coral polyps are short, lived microscopic organisms which live in colonies.
21. A Distributary: A distributary is that river which originates from a main river. It is formed near the river's mouth before it falls into the sea.
22. Gorge: The steep-sided narrow and deep valley of a river formed in its upper course is termed as a Gorge or a Canyon. It is also called an I – shaped valley. For example : The Brahmaputra gorge (5500m), and the Indus gorge.
23. A Rift Valley: A rift valley is the valley which has been formed as a result of the subsidence (sinking) of the landmass between two blocks due to faulting.
24. Sand dune: A mound ridge, or low hill of loose, windblown sand.
Fig. Sand dunes