Physical geography of Assam
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This article discusses the
Geology
Geomorphic studies also conclude that the
Some say that the "flow" is usually neutral. The flow includes water, land, air, and other resources too. Entering the Assam region, the Brahmaputra becomes a braided river, and, along with its tributaries, creates the flood plain of the Brahmaputra Valley.
Physiography
The state of Assam comprises three physiographical divisions, namely, the Brahmaputra Valley, the Barak Valley and the Karbi-Anglong and the North-Cachar hills.[1]
The Brahmaputra Valley in Assam is approximately 80 to 100 km wide and almost 1000 km long. The width of the river itself is 16 km at many places within the valley.
The hills of
The southern Barak Valley is separated by the Karbi Anglong and North Cachar Hills from the Brahmaputra Valley in Assam. The Barak originates from the Barail Range in the border areas of Assam, Nagaland, and Manipur and flowing through the district of Cachar, it converges with the Brahmaputra in Bangladesh. Barak Valley in Assam is a small valley with an average width and length of approximately 40 to 50 km.
Mineral resources
Assam is endowed with
. A small quantity of iron ore is also available in western parts of Assam.The Upper Assam districts are major reserves of oil and gas. Petroleum was discovered in Assam in 1889. It is estimated that Assam and surrounding region possess around 150 million tonnes of petroleum reserves. Presently, Assam is the 3rd largest producer of petroleum (crude) and natural gas in the country accounting for 16% and 8% respectively of the total production of this mineral in the country.
A Tertiary coal belt is located in
Assam has rich limestone reserves. The major reserves of limestone are in Dima Hasao and Karbi Anglong districts. A total reserve of 97 million tonnes of limestone has been found in these two districts and almost half of the reserve is of cement grade. Moreover, there is an estimated reserve of 365 million tonnes of limestone near Umrangshu in Dima Hasao district. Among the minor minerals, there are quartzite reserves in the
Climatic characteristics
With the 'Tropical Monsoon Rainforest Climate', Assam is a temperate region and experiences heavy rainfall and humidity. Winter lasts from late October to late February. The minimum temperature is 6 to 8 degrees Celsius. Nights and early mornings are foggy, and rain is scanty. Summer starts in mid May, accompanied by high humidity and rainfall. The maximum temperature is 35 to 38 degrees Celsius, but the frequent rain reduces this. The peak of the monsoons is during June. Thunderstorms and frequent storms known as Bordoisila are frequent during the afternoons during the Bihu season.
Biogeography and biodiversity
Assam is a part of the Biodiversity Hotspot area. There are a number of tropical
Apart from the rhinoceros and the tiger, the spotted deer or
A few of the major birds in Assam are: the
Assam is also known for
Natural disasters
The region is also prone to natural disasters. High rainfall, deforestation, and other factors which have resulted in annual floods. These often cause widespread loss of life, livelihood and property. The region is also prone to earthquake, mild tremors are common, but strong earthquakes are rare. There have been three strong earthquakes: in 1869 the bank of the Barak sank by 15 ft. In 1897 there was a tremor which measured 8.3 on the moment magnitude scale, and another in 1950 which measured 8.6.
References
- ^ Saikia, Partha. "Physiography of Assam and Assam Physiographical Divisions". North East India Info. Retrieved 2020-10-12.
External links
- Department of Geography, Gauhati University
- Department of Geological Sciences, Gauhati University - Profile and Contacts
- "Brahmaputra Valley Semi-evergreen Forests". Terrestrial Ecoregions. World Wildlife Fund.