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.
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.
CLIMATE, RAINFALL, TEMPERATURE AND
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.
The rocks of Darjeeling
district were sub-divided by Mr.Mallet into five groups, viz,Gneiss,
the Daling Series Gondwanas and the Tertiary system.
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
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.
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.
(A) NATURAL FOREST :
The natural forests of Darjeeling
district may be grouped into following broad categories:
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.
(B) MANMADE FOREST:
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.
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.
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.
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.