Western Ghats..

The Western Ghats also known as Sahyadri mountains, is a mountain range in the west of peninsular India. It runs north to south along the western edge of the Deccan Plateau, and separates the plateau from a narrow coastal plain along the Arabian Sea. The range starts near the border of Gujarat and Maharashtra, south of the Tapti River, and runs approximately 1600 km through the states of Maharashtra, Goa, Karnataka, Tamil Nadu and Kerala ending at Kanyakumari, at the southern tip of the Indian peninsula. About sixty percent of the Western Ghats are located in the state of Karnataka.

The Western Ghats mediates the rainfall regime of peninsular India by intercepting the southwestern monsoon winds. The western slopes of the mountains experience heavy annual rainfall (with 80 percent of it falling during the southwest monsoon from June to September), while the eastern slopes are drier; rainfall also decreases from south to north. Dozens of rivers originate in these mountains, including the peninsula’s three major eastward-flowing rivers..Thus, they are important sources of drinking water, irrigation, and power. The wide variation of rainfall patterns in the Western Ghats, coupled with the region’s complex geography, produces a great variety of vegetation types. These include scrub forests in the low-lying rainshadow areas and the plains, deciduous and tropical rainforests up to about 1,500 meters, and a unique mosaic of montane forests and rolling grasslands above 1,500 meters.

The extent of the ghats The Western Ghats, also known as the Sahyadri Hills, are well known for their rich and unique assemblage of flora and fauna. Norman Myers included the Western Ghats amongst the 25 biodiversity hot-spots identified in the world. Geologically the Western Ghats may be divided into two segments. The hills north of the Krishna basin (largely Maharashtra and Gujarat) with fragile basaltic rocks are results of the same processes that gave rise to the Deccan trap. Isolated, conical, flat-topped hills occur here with steep sides, marked with striations. They seldom rise beyond 1500 m. South of the Krishna basin is the region of precambrian archean crystalline hard rocks (nearly 2000 million years old granites, schists, gneisses, quartzites, etc). Soils vary from humus rich peat in the montane areas to laterite in the lower elevation and high rainfall belts. Soils are generally acidic.Arising abruptly from the narrow Konkan and Malabar coasts, these hills run 1600 km north-south between the river Tapti in Gujarat and Kanyakumari in Tamilnadu covering an area approximately equal to 160,000 sqkm. In the east, they slope gently towards the Deccan Plateau. The northernmost segment that extends into Gujarat merges in the east with the Surat Dangs. In the Nilgiris, Palanis and parts of Karnataka, the Western Ghats extend considerably eastwards, locally merging with the Eastern Ghats. Towards the south, the hill chain is divided into two by the Palghat Gap (a mere 13 km gap at its narrowest) rendering a physically homogeneous high altitude plateau into two rather distinct biogeographic units viz., the Nilgiris complex in the north and the Anaimalai-Palnis complex in the south.

Here are found the highest peaks viz., Anaimudi (Anaimalai Hills) and Doddabetta (Nilgiri Hills), reaching well over 2695 and 2637m ASL respectively. Apart from these, a number of peaks reaching heights of over 2000 m are present in the southern half as that in Tamilnadu (Palnis) and Kerala (eg. Highy Wavy Mountains and Grass Hills). Climatic conditions in the Western Ghats vary with the altitude and physical proximity to the Arabian Sea and the equator. Although the Western Ghats experience a tropical climate - being warm and humid during most of the year with mean the temperature ranging from 20oC in the south to 24oC in the north, the higher elevations experience subtropical climates and on occasions frost. Further, it has been observed that the coldest periods in the southern Western Ghats coincide with the wettest.

Whereas rainfall peaks of 9000 mm and above per year, are known locally, annual rainfall as low as 1000 mm are frequent in the east bringing the average to around 2500 mm. Interestingly, the total amount of rainfall received and the spread are not often correlated. Areas in the northern Western Ghats (in the State of Maharashtra) receiving the highest rainfall (locally over 9000 mm) experience dry weather over more than half the year. On the contrary, areas receiving much less rainfall in Kerala and closer to the equator experience rain almost all through the year. Much of the rainfall is received during the southwest monsoon season. Peak period of rainfall is July-August.

Flora and Fauna Four thousand species of flowering plants are known from the Western Ghats.Fifty-six genera of flowering plants are considered endemic to the Western Ghats. Recent studies have suggested that there could be 1500 species of flowering plants endemic to the Western Ghats. Although the exact number keeps varying with the author and time, what is of interest is that nearly 38% of all species of flowering plants in the Western Ghats are endemic. Sixty three per cent of India’s evergreen woody plants are endemic to the Western Ghats. Scientific research on the invertebrates of the Western Ghats has largely been restricted to a few groups of organisms..There are around 218 species of primary and secondary freshwater fishes in the Western Ghats.One hundred and twenty one species of amphibians and a similar number of mammals are known from the Western Ghats.The largest population of India's Tigers outside the Sundarbans is in the unbroken forests bordering Karnataka, Tamil Nadu and Kerala. The largest numbers and herds of vulnerable Gaur are found here with the Bandipur National Park and Nagarahole together holding over five thousand Gaur.To the west the forests of Kodagu hold sizeable populations of the endangered Nilgiri Langur. Bhadra Wildlife Sanctuary and project tiger reserve in Chikmagalur has large populations of Indian muntjac. Many Asian Elephant, Gaur, Sambar, vulnerable Sloth Bears, Leopard, tiger and Wild Boars dwell in the forests of Kerala.The Western Ghats form one of the three watershed of India, feeding the perennial rivers of peninsular India. Important rivers include the Tambaraparani River,Godavari, Krishna, and Kaveri. These rivers flow to the east and drain out into the Bay of Bengal. These rivers are fast-moving, owing to the short distance travelled and steeper gradient. Important rivers include the Mandovi, Zuari. Many of these rivers feed the backwaters of Kerala and Maharashtra. Rivers that flow eastwards of the Ghats drain into the Bay of Bengal. These are comparatively slower moving and eventually merge into larger rivers such as the Kaveri and Krishna. Smaller rivers include the Chittar River, Bhima River, Malaprabha River, Manimuthar River, Kabini River, Kallayi River, Kundali River, Pachaiyar Riverand the [[Pennar River] and Periyar.