Wednesday, December 4, 2013

Climate

Climate in the Western Ghats varies with altitudinal gradation and distance from the equator. The climate is humid and tropical in the lower reaches tempered by the proximity to the sea. Elevations of 1,500 m (4,921 ft) and above in the north and 2,000 m (6,562 ft) and above in the south have a more temperate climate. Average annual temperature here are around 15 °C (60 °F). In some parts frost is common, and temperatures touch the freezing point during the winter months. Mean temperature range from 20 °C (68 °F) in the south to 24 °C (75 °F) in the north. It has also been observed that the coldest periods in the south western ghats coincide with the wettest.

During the monsoon season between June and September, the unbroken Western Ghats chain acts as a barrier to the moisture laden clouds. The heavy, eastward-moving rain-bearing clouds are forced to rise and in the process deposit most of their rain on the windward side. Rainfall in this region averages 3,000–4,000 mm (120–160 in) with localised extremes touching 9,000 mm (350 in). The eastern region of the Western Ghats which lie in the rain shadow, receive far less rainfall averaging about 1,000 mm (40 in) bringing the average rainfall figure to 2,500 mm (150 in). Data from rainfall figures reveal that there is no relationship between the total amount of rain received and the spread of the area. Some areas to the north in Maharashtra while receiving heavier rainfall are followed by long dry spells, while regions closer to the equator receiving less annual rainfall, have rain spells lasting almost the entire year.

Mountains of Western Ghats

Hill ranges

The Western Ghats extend from the Satpura Range in the north, go south past Maharashtra, Goa, through Karnataka and into Kerala and Tamil Nadu. Major gaps in the range are the Goa Gap, between the Maharashtra and Karnataka sections, and the Palghat Gap on the Tamil Nadu and Kerala border between the Nilgiri Hills and the Anaimalai Hills.


Sahyadhris

The major hill range starting from the north is the Sahyadhri (the benevolent mountains) range. This range is home to many hill stations like Matheran, Lonavala-Khandala, Mahabaleshwar, Panchgani, Amboli Ghat, Kudremukh and Kodagu. The range is called Sahyadri in Maharashtra, Karnataka and Sahya Parvatam in Kerala.


Nilgiris

The Nilgiri Hills,also known as the Nilagiri malai, are in northwestern Tamil Nadu. The Nilgiri Hills are home to the hill station Ooty. The Bili giri rangana Betta southeast of Mysore in Karnataka, meet the Shevaroys (Servarayan range) and Tirumala range farther east, linking the Western Ghats to the Eastern Ghats. In the South, the range is or Nilgiris in Tamil Nadu.


Anaimalai Hills

South of the Palghat Gap are the Anaimalai Hills, in western Tamil Nadu and Kerala. Smaller ranges are further south, including the Cardamom Hills.
In the southern part of the range is Anamudi peak 2,695 metres (8,842 ft) in Kerala the highest peak in Western Ghats. Chembra Peak 2,100 metres (6,890 ft), Banasura Peak 2,073 metres (6,801 ft), Vellarimala 2,200 metres (7,218 ft) and Agasthya mala 1,868 metres (6,129 ft) are also in Kerala. Doddabetta in the Nilgiri Hills is 2,637 metres (8,652 ft). Mullayanagiri is the highest peak in Karnataka 1,950 metres (6,398 ft). The Western Ghats in Kerala and Tamil Nadu is home to many tea and coffee plantations.
The northern portion of the narrow coastal plain between the Western Ghats and the Arabian Sea is known as the Konkan Coast or simply Konkan, the central portion is called Kanara and the southern portion is called Malabar region or the Malabar Coast. The foothill region east of the Ghats in Maharashtra is known as Desh, while the eastern foothills of the central Karnataka state is known as Malenadu.The largest city within the mountains is the city of Pune (Poona), in the Desh region on the eastern edge of the range. The Biligirirangan Hills lies at the confluence of the Western and Eastern Ghats.
The mountains intercept the rain-bearing westerly monsoon winds, and are consequently an area of high rainfall, particularly on their western side. The dense forests also contribute to the precipitation of the area by acting as a substrate for condensation of moist rising orographic winds from the sea, and releasing much of the moisture back into the air via transpiration, allowing it to later condense and fall again as rain.
 

Geology of Western Ghats

The Western Ghats are not true mountains, but are the faulted edge of the Deccan Plateau. They are believed to have been formed during the break-up of the super continent of Gondwana some 150 million years ago. into being somewhere around 100 to 80 mya after it broke away from Madagascar. After the break-up, the wesGeophysicists Barron and Harrison from the University of Miami advocate the theory that the west coast of India came tern coast of India would have appeared as an abrupt cliff some 1,000 m (3,300 ft) in elevation.
 
 
 
Basalt is the predominant rock found in the hills reaching a depth of 3 km (2 mi). Other rock types found are charnockites, granite gneiss, khondalites, leptynites, metamorphic gneisses with detached occurrences of crystalline limestone, iron ore, dolerites and anorthosites. Residual laterite and bauxite ores are also found in the southern hills.
 
 
 

Introduction to Western Ghats

The Western Ghats or the Sahyādri constitute a mountain range along the western side of India. It is a UNESCO World Heritage Site and is one of the eight "hottest hotspots" of biological diversity in the world. It is sometimes called the Great Escarpment of India.The range runs north to south along the western edge of the Deccan Plateau, and separates the plateau from a narrow coastal plain, called Konkan, along the Arabian Sea. A total of thirty nine properties including national parks, wildlife sanctuaries and reserve forests were designated as world heritage sites - twenty in Kerala, ten in Karnataka, five in Tamil Nadu and four in Maharashtra.


The range starts near the border of Gujarat and Maharashtra, south of the Tapti river, and runs approximately 1,600 km (990 mi) through the states of Maharashtra, Goa, Karnataka, Tamil Nadu and Kerala ending at Kanyakumari, at the southern tip of India.


These hills cover 160,000 km2 (62,000 sq mi) and form the catchment area for complex riverine drainage systems that drain almost 40% of India. The Western Ghats block rainfall to the Deccan Plateau. The average elevation is around 1,200 m (3,900 ft).


The area is one of the world's ten "Hottest biodiversity hotspots" and has over 5000 species of flowering plants, 139 mammal species, 508 bird species and 179 amphibian species; it is likely that many undiscovered species live in the Western Ghats. At least 325 globally threatened species occur in the Western Ghats.