Physical Features of Darjeeling

The Darjeeling district with a geographical area of 3,149 sq.kms., is an irregular triangle in shape. The Northern boundary commences on the west at the peak of Phalut nearly 3657.6 meters high,the junction of the boundaries of Nepal and Sikkim. This boundary runs east from Phalut along a ridge descending to the Ramam river. From there , the boundary follows the course of that river until it joins the Rangit and then follows the great Rangit until it reaches the Tista.Proceeding east of that junction, the boundary follows the Tista upstream until its junction with the Rangpochu,thence it proceeds first up the Rongpochu and then up the Rushattchu, thence the Rushattachu and Sikkim and Bhutan boundary as marked by pillars to the Nechu to its junction with the Dochu or Jaldhaka, thence in that river southward until the Jalpaiguri district is reached in the Khumani forest.

On the west , the district is bounded by Nepal. From Phalut, the western boundary follows the southward ridge until it joins the Mechi river which continues as the boundary right upto the plains, thence by the boundary of Nepal the south-western corner of the district. On the south lies the district of Purnea and West Dinajpur intercepted by the Mahananda river and on the east, the district is bounded by Bangladesh and the Jalpaiguri district. The natural features consist of a portion of the outlying hills of lower Himalayas and a stretch of territory lying along the base of the hills known as the Tarai. The Tarai is only 91 meters high above the sea level, but there are parts of the district in the hills which are nearly 3657.6meters high. The hill portion of the district is like a labyrinth of ridge and narrow valleys. There are no open valleys or plains or lakes. Most of the ridges are forest clad and in the lower slopes, tea plantation and crop cultivation are done.

The Darjeeling district presents a great variation of climate. As the district consists of two distinct tracts, the ridges and deep valley of lower Himalayas and the altitude varies between 300 m - 3,600 m. In the Tista valley, the climate is subtropical while in the hills, it is temperate. The bulk of the forest areas witness temperate climate although considerable local changes in the configuration and aspects influence climatic condition which often varies through a wider range. The winter in Darjeeling is extermely cold and extends from December to March. The Summer spreads from April to mid June and during this period Darjeeling is delightfully cool. The rainy months are June to September when most of the rainfall occur with appreciable amounts in May and October as well.

Geology -

The rocks of Darjeeling district were sub-divided by Mr.Mallet into five groups, viz,Gneiss, the Daling Series Gondwanas and the Tertiary system.

Soils -

The soil of the upland is usually red and gritty while that of the plains is dark and more fertile. Red and Yellow soils have developed on the gneisses and schists in the higher slopes of the Darjeeling Himalaya. The soil every where is residual, i.e.,derived by the weathering of the underlying rocks.

Minerals -

The metamorphic rocks of Darjeeling and Daling series contain deposits of copper, nickel, iron and precious stones. Lying south of the metamorphic occur the Gondwana belt passing through Tindharia.

Climate -

Due to tremendous narration of altitude,differences in aspects the climate within the hill areas vary greatly. In general the hill areas enjoy pleasant summer, heavy rain in rainy season due to strong monsoonal winds and cold winter after added with snowfall in higher altitudinal areas. In Darjeeling hill areas, April,May and Sept - October form the peak tourist seasons due to pleasant climatic conditions. Darjeeling receives about 3000mm of rainfall. The mean maximum temperature is approximately 11.1degree celsius and minimum temperature is 1.7 degree celsius.

The natural forests of Darjeeling district may be grouped into following broad categories:

a) Tropical Semi-Evergreen Forest: This type of forest are restricted to foothills. The important species are Michelia champaca, Terminalia myriocarpa. Ailanthus grandis, Phoebe species. All these species yield valuable commercial timbers.

b) Tropical Moist Deciduous Forest: Most deciduous forest have Shorea robust as important species. Among its associates, the species like Michelia champaca, Schima wallichii and Chukrassia velutina which are interspersed with riverain forests of Acacia catechu, Dalbergia sissoo and Bombax ceiba,exist.

c) Sub-Tropical Forest: These forest occur up to an elevation of 1,824 m (refer under sub-tropical broad-leaved hill forests by Champion and Seth, 1968). The common species are Betula cylindrostachys and Alnus nepalensis, Schima wallichii and Engelhardtia spectata etc.

d) Eastern Himalayan Wet Temperate Forest: These forest occurs from about 1,824 m and extend upto 3000m (refer under Montane wet temperate forests by Champion and Seth, 1968). The major species are Michelia excelsa, Abies densa, Tsuga brunoniana and species of Machilus, Acer, Quercus (oaks) etc.

e)Alpine Forest: These forest are found over 3000 m (refer sub-alpine, dry and moist alpine forest of Champion and Seth,1968). The characterstic stunted species are Rhododendron Salix, Berberis,often Junipers, Abies and Tsuga.

The valuable indigenous species form the main component of the plantation in the district. An exotic conifer, Cryptomeria japonica, has done exceedingly well in the hill forests of the Darjeeling district. Other exotic conifers like Pinus petula, Cupressus species etc. have also shown great promise in the region.

A rapid forest cover appraisal using satellite imageries gives a fair idea of forests and forest cover in the district.Forest survey of India has been assessing forest cover of the entire country on a 2 year cycle through interpretation of satellite data.The state wise and district wise data on the extent of the forest cover are also given in the publication named "State of Forest Report".The last such report was published in 1993 which incorporates data interpreted and checked in field during 1990-92. According to this report, extent of dense forests and open forests in Darjeeling district amounts to 1093 sq.km. and 362 sq.km. respectively and the total forest cover is assessed at 1455 sq.km. in the district.

A second set of data has been generated by forest covers mapping by West Bengal State through digital image processing of Indian Remote Sensing satellite and forest change detection studies on nine districts of West Bengal through digital image processing between 1988 and 1991 which were accompolished in joint colloboration between Forest Department, West Bengal and Regional Remote Sensing Centre, Kharagpur Indian Space Research Organisation, Govt.of India.

The river of the district drain ultimately to the south, through the west to ridge across it causes a series of Tista tributaries rising on its northern face to flow northwards and others flow east or west before joining the main river. The rivers of the district are, Tista which rises in glacier, in North Sikkim, 21 000ft above sea level, Great Rangit, Jaldhaka, Mahanadi, Balason and Mechi.