Project Report / Essay on "Monsoon in India"
INDIA'S Monsoon
Introduction
This is Project Report/Essay on Monsoon of India - Our country is a land of
great diversity in climate. There are wide seasonal variations as well as
variations between day and night. These variations are observed in
temperature. A word of monsoon use derived from the Arabic word 'mousam'
which means season.
There are four season of Monsoon in India
- Cold weather season
- Weather season - Monsoon season
- Retreating monsoon season.
The zone of high
temperature shift north words owing to the apparent north word movement of
sun. Minimum temperature exceeds 400C
over most part of North India during May. During the cold weather season.
Low temperature conditions brevaid in the Northern plains. This result in
the formation of a high pressure in the northern plains. Cold and dry winds
blow out from this high pressure. North east trade winds prevail over the
Bay of Bengal and the peninsula most parts of India have fine weather with
clear skies. Parts of North-West. India are affected by western disturbances
which originate in the medi terranesn sea. These disturbances give rainfall
and snow fall to parts of Jammu and Kashmir, Punjab, Himachal Pradesh and
Haryana parts of Tamil Nadu cost also get rain fall from north east winds
blowing over the Bay of Bengal.
Advancing Monsoon season
is a blessing if it rains in time. It gives peace and pleasure to all.
Monsoon season in summer gives us great relief. It lessens the heat the
temperature comes down. The air becomes cool. Men, animals and birds all
feel refreshed. The leaves of trees have a glistening shire. The gardens
look charming. Monsoons season in winter is dreaded by all. Then we are
remained of saying. 'Lay by something for a rainy days. Except for
ultimately or excessive rains a monsoon season in India are greeted Is
equally useful to animal and plant life. It is important to men life also.
Monsoon in India
The four months namely June, July, August, September form the core of the
rainy season almost all over India. This duration of the rainy season.
However goes on decreasing from south to north and from east to west. In the
extreme north west it is barely two months. Between three-fourths and
nine-tenths of the total rain fall is concentrated over his period. This may
gives us an idea of how unevenly it is distributed over the year. The low
pressure conditions over the north - western plains get further intensified
By early June they are powerful enough to attract the trade winds of
southern Hemisphere. These south-east trade winds are of oceanic origin
coming from the Indian ocean they cross the equator and enter the Bay of
Bengal and the Arabian sea, only to be caught up in the air circulation over
India. Passing over the equatorial worth currents they bring with them
moisture in abundance. After crossing the equator they follow a south -
westerly direction. This is why they are known as south west monsoon. Thus
the north east-trades of winter, originating on the land are replaced by
diametrically opposite south west monsoons laden with a moisture. The
monsoon unlike the trades are not steady winds. They are essentially
pulsating in nature. The rain bearing winds are strong. They blow at an
average speed of 30 KM per hour barring the extreme north west they over run
the country in a month's time the sudden approach of the moisture - laden
winds is associated with violent thunder the lighting. This us known as
'break' or 'burst' of the monsoon. It is of interest to note that these
monsoon winds follows a south-westerly direction. But as they approach the
land their direction is modified by the relief and thermal low pressure over
north-west India. To begin with, the Indian peninsula divides the monsoon
into two braches. They are the Arabian sea branch and the Bay of Bengal
branch. The Arabian sea branch of the monsoon is obstructed by the western
glades. The wind are side of the sahyadris receive very heavy rains.
Crossing the ghats they overrun the ocean bateau and Madhya Pradesh causing
fair amount of rainfall. Thereafter they enter the Ganga-plains and mingle
with the Bay of Bengal branch. Another part of the Arabian sea branch
strikes the saurashtra peninsula and the kachchh. It then passes over west
Rajasthan and along the Araballis, causing only a scanty rainfall. In Punjab
and Haryana, it too joins the Bay of Bengal branch. These two branches. The
Bay of Bengal branch is naturally directed towards the coast of myaninsar
and part of south-east Bangladesh. But the Arabian Hills along the coast of
Myamar are good enough to defect a big chunk of this branch, enabling it to
enter the Indian subcontinent. The monsoon, there fore enter west Bengal and
Bangladesh from south and south east instead of the south westerly
direction. There after this branch splits into two under the influence of
the one branch moves west ward along the Ganga plains reaching as far as the
Punjab plains. The other branch moves up the Brahmaputra vally in the north
and north east coursing widespread rains in the North eastern India. Its
sub-branch strikes the Garoand Khasi Hills of Meghalaya Mawsyntain located
on the crest of the sough tern range of khasi Hills, receives the highest
average annual rainfall in the world. Cherapunji, located 16 km east of
Mawsynrain holds some other rainfall records. Distribution of rainfall
received from south west monsoon is very largely governed by the relief or
orography for instance, the wind ward side of the Western Ghats registers a
rainfall of over 250 centimeters. On the other hand the leeward side of
these ghats is hardly able to receive 50 cm. Again the heavy rainfall in the
north eastern states can be attributed to their hilly ranges and the eastern
Himalayas. The rainfall in the northern plains goes on decreasing from east
to west During this particular season Calcutta receive about 120 cm, Patna
102 cm, Allahabad 91 cm and Delhi 56 cm.
Forms of Precipitation
Common forms of precipitation are rainfall, drizzle, snow fall, sleet, and
hail.
(1)
Rainfall -
This is the most common form of precipitation. It consists of
water falling in drops from the clouds. The size of rain-drops varies from
0-5 mm to 6 mm in diameter. The ascent of large masses of air is essential
for rainfall to occur. The ascent may be brought about in three ways.
corresponding to these there are three main types of rainfall :
Convectional, cyclonic and orographic.
(a) Convectional rainfall :-
Convectional rainfall is caused by the process of convection in the
atmosphere the sun reads the earth’s surface which, in turn heats air near
the ground. The warm cur rises in fast convection currents. The rising air
is cooled till it's dew point is reached now the water vapor condenser I
clouds form, and rainfall occurs. Convectional rainfall is common in
equations region. It occurs as heavy downpour, often accompanied by thunder.
Cyclonic rainfall :-
This type of rainfall is also called frontal rainfall. It is associated with
the passage of a cyclone. It occurs when a warm air mass overrides a damson
mass of cold air along a front condensation takes place, with cloud
formation and rainfall ahead of the front.
Orographic rainfall :- This type of rainfall is caused by
mountains standing in the path of moisture- laden air the air is forced to
rise and is thereby cooled. Clouds form and rain fall on the wind ward slaps
of the mountain. The air is almost free of moisture when it descends over
the other side of the mountain. This side, called the leeward slope,
receives relatively light rain, or no rain. It is, therefore, an area of dry
climate and is often called a rain shadow area.
(2) Drizzle :-
Rainfall in fine raindrops of less than 0-5 mm diameter is called drizzle.
The fine droplets of drizzle appear to float following the lightest movement
of air. The Drizzle falls continuously from law, thin - layered clouds. It
is often associated with fog and poor visibility.
(3) Sleet :-
Rain that is Frozen or partially frozen is called sleet. It is produced when
rainfalls through a cold layer of air near the earth's surface.
(4) Snowfall :- Precipitation in the form of minute ice crystals is
called snowfall. It occurs when water vapor condenses at temperatures below
00C.
and the lower atmosphere is sufficiently cool. These conditions are
essential for ice crystals to reach the ground without melting. Snowfall is
common in middle and high latitude.
(5) Hail :-
The roundest pellets of ice that fall from esdense cumulus
clouds of immense vertical height are called hail or hailstones. Hailstones
range from 5 mm to 5 cm in diameter. These are formed when there are strong
vertical currents of air. Condensation then occurs at very high altitudes at
very low temperatures. The pellets of ice formed within the clouds
repeatedly rise and fail with draughts. They keep colliding with super
cooled water droplets which instantly freeze on them. They grow larger and
heavier by deposition of ice layers. Where as they are too heavy to be
sustained by an up draught, they fall to the ground. The internet structure
of hail reveals several concentric layers of clear ice alternating with
milky layers of ice.
Regional distribution of Monsoon in India
Regional distribution of rainfall in general. The amount of rainfall
decreases (a) away from the quarter on either side up to 30. north and
south, and (b) from the coasts to wards the interior of continents.
According to the amount of annual rainfall. There are five broad rainfall
regions :
(1) Region of heavy rainfall (above 200 cm) which includes four distinct
areas :
(i)
Equatorial zone of doldrums where the temperature are very high through the
year. The sun-warmed earth causes the humid surface air to rise in
convectional currents resulting in heavy. Convectional rainfall. The maximum
of heating is usually in the early afternoon. At this time there is a sudden
downpour, often accompanied by thunder and lightning. During the season of
heaviest precipitation, rain falls almost every day. There is no definite
dry season. However, there is often a less wet season, particularly in these
portions of the region which are further away from the equator.
(ii)
Western coasts of continents in the zone of westernizes in cool temperature
zone where the westernizes blowing from sea to land bring heavy rainfall.
The rainfall is mainly associated with the passage of mid-latitude cyclones.
(iii)
Coastal areas of monsoon lands which receive heavy rainfall from strong
winds blowing from the Indian ocean towards low pressure areas in the
interior of Asia during summer. The rainfall is particularly heavy on the
windward slopes of mountains where it is orographic rainfall.
(iv)
Windward slops of mountain ranges which intercept ocean winds causing heavy
rainfall on their wind ward slopes. These ocean winds are the south-west
monsoon in the western ghats, Himalays, and Araban Yoma, and westerlies in
the Rockies, Alps, and Andes.
2. Region of moderate rainfall covering the castern coastal
lands of the sub tropical belt. Main areas are most of the Brazilian
Highlands in south America, most of central Africa, central north-east
India, most of the central basins of lrrawady, Mekong, sikiang and yongize
rivers, north Australia and south-east USA. These area surround the areas of
heavy rainfall. The receive rainfall from trade sends and monsoons which
have already shed much of their moisture in the high- rainfall areas. As
such, these areas receive only moderate amounts of rainfall.
3. Region of low rainfall (50 cm to 100 cm) which includes-
(i) Interiors of continents in tropical latitudes - central- west
south Americal, Central - west India, central - north and east Australia and
central - east Africa ; and
(ii) West interior and east interior margins of continents in the
temperature latitudes - Hwang No plain and surrounding lands in eastern
Asia, west - central Europe, Central - east U.S.A., and north east Canada.
These areas receive rainfall from winds which have greatly exhausted
themselves on wass. As such, the amounts of rainfall received are law.
4. Region of scanty rainfall (25 cm to 50 cm) which includes-
(i) Margins of tropical zone - central - west Australia, central
southern south America, central - southern Africa, borderland of Sahara, and
parts of central - west Asia ; and
(ii) Northern margin of cool temperature zone - central USSR; west - central
USA ; and central Canada.
The prevailing winds become relatively dry by the time they enter these
areas. Hence only scanty rainfall is received.
5. Region of very scanty rainfall. The various areas in this
region are all called deserts.
Deserts are of three types :
Hot deserts, mode - latitude deserts, and cold deserts.
Hot deserts along the western margins of continents in the trade wind belt.
These are also called tropical deserts. They receive very scanty rainfall as
the coins blocking in from landmasses are almost dry. Principal hot deserts
are the Sahara desert in north Africa; Kalahari desert in south Africa,
Arabian desert in south west Asia ; West Australian desert in Australia, and
Atacama desert in south America.
Mid - latitude deserts are located in the interior regions of large
containments, for away from the range of rain-bearing winds from the oceans.
Principal mid-latitude deserts are the Gobi-desert in south America. cold
deserts die in the Eurasian and Canadian tundra and in the lands around the
north and the south poles. Precipitation in these deserts occurs as
snowfall. 11-2. Seasonal distribution of rainfall. Rainfall is very unevenly
distributed over the Earth's surface, and different places have chief rains
occurring at different seasons. Seasonal distribution of rainfall may be
summarized under the following categories :
1. Areas having rainfall at all seasons. These are -
(i) Equatorial low pressure belt, extending for a few degrees on
either side of the equator, which has two very wet seasons and two rather
lese wet seasons in the year.
2. Western margins of continents in the coal temperature zone
which lie in the rack of the westernizes. These winds bring moisture - laden
winds from oceans at all times. Further, depressions causing cyclonic rains
occur throughout the year. However, more rain falls in autumn and winder
than in the rest half of the year.
tropical deciduous forests
These are called the monsoon
forests between 200 cm. & 75 cm. These forests easily catch fire. They are
divided into two groups :
(i) Noist which are found on the slopes of
western ghats having took as an important species.
(ii) The most deciduous forest found in north-eastern
part of the Peminsula i.e. around chhotanagpers plates covering cast Madhya
Pradesh, South Bihar and West Orissa along with Shivalias in the north
having sat as the most important tree.
The Thorn and Scrus Forests :
These forests are found in region of 75 cm. rainfall, spreaded over
north-western part of the country from saurashtra in the south to Punjab
plains in the north, alongwith northern Madhya Pradesh, South-West Uttar
Pradesh and Bundelkhand plateau, in the last having Kikar, Babul, Khair,
Date palsns as most useful trees. They gradually fack away into scrubs and
thorny bushes, which constitute the typical desert vegetation.
This is Project Report on Monsoon in India.
