This document provides an overview of the geography and climate of Tripura, India. Some key points: - Tripura has a tropical humid climate (Koppen classification Aw) with four main seasons: winter, pre-monsoon, monsoon, and post-monsoon. - The state has hilly terrain with five mountain ranges running north to south. Elevation ranges from 50-3,080 feet. Major rivers include the Gomati, Khowai, and Manu. - Temperature ranges from 13-27°C in winter and 24-36°C in summer. Most rainfall occurs April-September during the monsoon season. Annual rainfall varies from 1,922-

1. CHAPTER-I
INTRODUCTION
1.1 JUSTIFICATION OF THE STUDY
climate is an important element of the physical environment of man for which all of his
activities depends on it .The word “climate” is derived from Greek word ‘kilma’ which means
‘inclination’ and is defined as the average weather condition over a longer period of time
.According To koppen and De long ‘climate is a summary, a composite of weather condition
over a long period of time; truly portrayed, it includes details of variations-extremes,
frequencies, sequences of the weather elements which occur from year to year, particularly
in TEMPERATURE and PRECIPITATION. Climatology is the science that seeks to describe
and explain the nature of the climate, why it differs from place to place and hoe it related to
other elements of the natural environment and to human activity.
TRIPURA is one of the seven states in North-eastern part of India. It is bounded on the
north, west; south and south east by Bangladesh where as in the east with Assam and
Mizoram. It has Hot humid type of climate (koppen),(Aw). The undulating topography leads
to local variations, particularly in the hill ranges.] The four main seasons are winter, from
December to February; pre-monsoon or summer, from March to April; monsoon, from May
to September; and post-monsoon, from October to November. The month of October is
comparatively pleasant as regards weather. Winter season elongates from November to
February, where the average minimum temperature remains 10.5°C. In summers, light
cotton clothing is required to stay cool in hot and humid surroundings; while heavy woollens
are essential in winters.
1.2 LITRATURE REVIEW:
Literature review is an integral part o f the research process and makes a valuable
contribution to almost every operational step. It provides a theoretical background to
your study. It helps you establish the links between what you are proposing to examine and
what has already been studied.
According To H.J Critchfield (2002) in his book “general climatology”, explains the
processes of exchange of heat and moisture between the earth and the atmosphere over a
period of time, results in conditions which we called climate. It is the aggregate of the
atmosphere conditions involving heat, moisture and air movement. Climate both exhibits
both spatial and temporal variations throughout the world.
C.S Thornthwaite (1961) in his article “The Task Ahead”. He had given a comprehensive
and systematic analysis of climate. He was of the opinion that the climatic characteristics of
a region of the world depends on the nature of exchange of momentum, heat as well as the

2. moisture of the earth’s surface and atmosphere. Thus the climate or locality represented
the equilibrium between the receipt and the expenditure of the radiant heat as well as
moisture. According to him, it is the heat and moisture of the area that explains the climate.
In accordance to A.P.M Baede (2001) in his book “THE CLIMATE SYSTEM: AN OVER
VIEW”, weather and the climate profoundly influence life on the earth. Human experience
them everyday .As both climate and weather are essential for health ,food production, and
well being not only weather but also human induced climate change can a matter of some
concern. Climate varies from place to place and depends on altitude, distance from the sea,
vegetation, and presence or absence of mountains, or other geographical factors.
W.G Kendrew (1957) in his book “CLIMATOLOGY”, he describe that climate is a
composite idea, a generalisation of the manifold weather condition from day to day through
the year. He aptly remarked that the climate is the most fundamental and far reaching of
the elements which controls life. According to him vegetation of the earth is closely depends
on it.
According to Anandeshwari Awasthi - Climatology studies the spatial distribution of
average values of the climatic elements e.g. Temperature, rainfall, pressure, and wind,
humidity and evapotranspiration, and their relation to man’s activities, weather is the state
of atmospheres. Its consists of the short-term variation of the atmospheric conditions.
Ellsworth Huntington, considered in his book “THE CLIMATE HYPOTHESIS OF
CIVILISATION” that climate is the most dominant and essential factors in the development
of civilisation. He emphasised the historical fact that many advances civilisation in the past
have grown up and flourished in the different region of the world having dissimilar climatic
regime ranging from hot and barren cold to cold highlands. But as when the climate
conditions changes to become adverse, that civilisation decayed and prised. However, some
of the climatic effects are so such a great consequences and significance that they deserve a
careful consideration.
The climate of a specific area is represented by the statistical collection its weather
condition during a specific interval of time usually (30 years or more).
1.3 STATEMENT OF THE PROBLEM:
As we know that, weather is a dynamic phenomenon. It keeps on changing; and frequently
changes. These changes are from one day to other, one place to other. These are mainly due
to the variation in quantity, intensity, distribution of the elements of the weather and
climate. Similarly, there are variations in climatic conditions from one place to another. The
factors that control the elements include altitude, altitude, unequal distribution of land and
water, ocean currents, air pressure and winds, mountain barrier, nature ground water.

3. With all these factors the main significance of the study is to attempt to show and find the
variation of elements of climatic conditions in the past century and to analyse it. As we
know, that Tripura falls under tropical type of climate, CYCLONE, STORMS and
Thunderstorms are common in pre-monsoon seasons and all these are affected by the
factors, it is on a changing track of its climatic and weather condition, years after years; with
the climate change of the earth. This is the main environment issue of the contemporary
world.
1.4 OBJECTIVES TO FULFILL:
1. To understand the climatic characteristics of the region, and to show the relation
between them.
2. To highlight the distributional pattern of RAINFALL and TEMPERATURE of the Districts.
1.5 (LOCATION) STUDY AREA:
Tripura is a blocked-in hilly state with elevation ranging from 50 to 3080 ft above sea level. It
shares its borders with Assamand Mizoram on the east and Bangladesh on the north, west,
and south. It is only accessible through the Cachar district of Assamand Aizawl district of
Mizoram to the rest of the country. Tripura is situated between the latitudes of 22°56'N -
24°32'N and the longitudes of 90°09'E - 92°10'E. With an area of 10,492 sq. km Tripura is the
third smallest state of the country. It measures about 184 km from north to south and 113
km from east to west. The physiography is characterised by hill ranges, valleys and plains.
The stat has five anticline ranges of hills running north to south, from Baromura in the west.
1.6 DATA BASE AND METHODOLOGY:
With the aspects of climatic conditions of the area, the main focus of the research is
to elaborate the general results from the secondary data collected from different
sources.
 The data base has to be rigoursly checked and put into represented forms
and calculated in order to get rid of the erroneous data.
The profile of yearly data recorded for temperature and precipitation has to be
prepared and analyzed.
 The data recorded will be analysed through decades and,

4.  Methods like statistical techniques, cartographic techniques, flow charts, bar
diagram, line diagram and maps are to be applied.
1.7 CHAPTER PLAN/SCHEME:
 INTRODUCTION
 GEOGRAPHICAL BACKGROUND
 PHYSICAL SET-UP OF THE STUDY AREA(location)
 THERMAL CHARACTESICS (TEMPERATURE) analysis.
 MONSOONAL CHARACTERSTICS (PRECIPITATION) analysis.
 FINDINGS OF THE RESEARCH TOPIC.
 CONCLUSIONS
 REFERENCES.

5. CHAPTER- II
GEOGRAPHICAL BACKGROUND OF TRIPURA
2.1 LOCATION:
Tripura State lies in the eastern part of India, bordered by Bangladesh to the west, south
and north, by Assamto the north-east, and by Mizoram to the east. It is bounded by
latitudes 22°56’N and 24°32’N, and longitudes 91°10’E and 92°21’E. It has an area of 10,477
sq. km., and is a rugged and geologically a younger terrain. It has a link with Assamand rest
of the country through the adjoining Cachar district, lying to the northeast. It is connected
through National Highway (NH-44) and takes around 2(two) – 3(three) hours to reach the
District headquarter from Agartala.
2.2 SIZE AND SHAPE:
Tripura the third‐smallest state in the country is one of the eight north eastern states
covering an area of 10,491 km2 and is bordered by Bangladesh to the north, south, and
west, and the Indian states of Assamand Mizoram to the east. As of 2011, the state had
3,671,032 residents. The state is a part of the Burma Valley characterized by alternate ridges
and valley. Its maximum extent measures about 184 km (114 mi) from north to south, and
113 km (70 mi) east to west. At an altitude of 939 m, Betling Shib in the Jampui range is the
state's highest point.
2.3 PHYSIOGRAPHY OF TRIPURA:
The physiography is characterised by hill ranges, valleys and plains. The
state has five anticlinal ranges of hills running north to south.
The intervening synclines are the Agartala–Udaipur, Khowai–Teliamura, Kamalpur–Ambasa,
Kailasahar–Manu and Dharmanagar–Kanchanpur valleys. At an altitude of 939 m
(3,081 ft), Betling Shib in the Jampui range is the state's highest point. The small isolated
hillocks interspersed throughout the state are known as tillas, and the narrow fertile alluvial
valleys, mostly present in the west, are called lungas. A number of rivers originate in the hills
of Tripura and flow into Bangladesh.
The terrain is mostly undulating & hilly with small water streams (chharas),
rivers and fertile valleys intervening. Major rivers originating from Dhalai are Dhalai, Khowai,
Gomati& Manu. Major hills are Atharamura, Longtharai, Kalajhari& part ofSakhan. The
topography is immature. The major geomorphic elements observed in the area are both
structural and topographic ‘highs’ and ‘depressions’, ‘flats’ and ‘slopes’, sculptured on
the topographic surface in a linear and areal fashion.
2.4 GEOLOGICAL STRUCTURE:
The geology of the state is represented by sedimentary rocks with range in age from
Miocene to loosely consolidated sediments of recent age. The climate is humid sub-tropical

6. characterized by high rainfall. The state of Tripura represents the western fringes of typical
“ridges and valleys” province of the Tertiary fold mountain belt, commonly known as Indo-
burman ranges (purvanchal range). The general elevation varies between 780 m in the north
east part to 15m in the western part above sea level. Five prominent roughly north to south
trending anticline strikes ridges treaverse the states from east to west; these are jampui,
sankhantlang, longtarai,Atharamurra, and abaramura. This strike ridges from watershed of
the meghna basin of Bangladesh fed by khowai, haora, juri, manu, dhalai, deo, muhuri, feni,
gomati rivers.
2.5 SOIL:
Soils are one of the most precious natural resource. It is, therefore, important to maintain
soils.In a State of high productivity on sustainable basis.
The soils belong to 5 orders, 7 suborders, 9 great groups and 19 subgroups. The soil orders
are Inceptisols, Entisols, Ultisols, Alfisols and Histosols which occupy 80, 9, 7, 5 & 0.2
percent respectively.
2.5.1 Types of soils:
a. reddish yellow brown sandy soil (3468)sq.km(33.6)%
b.red loam and sandy loam soil (4514) sq.km (43.07)%
c.older alluvial soil (1019)sq.km(9.71)%
d. younger alluvial soil(980)sq.km(9.34)%
e. laterite soil (510)sq.km (4.86)%
2.6 CLIMATE:
The State of Tripura experiences Humid Sub-tropical type of climate. The features of
climate, however, vary between its different parts of the State. There are only two
Meteorological Observatories at Agartala and Kailasahar in Tripura having the facility to
record temperature and other weather information. Designated Aw under the Köppen
climate classification. The undulating topography leads to local variations, particularly in the
hill ranges.
The four main seasons are:
A. Winter- from December to February. , temperatures range from 13 to 27 °C
B.Pre-monsoon or summer- from March to April, temperatures is between 24 and 36 °C
c. Monsoon-from May to September, the south west monsoon brings heavy rains, which
cause frequent floods.
D.Post-monsoon -from October to November. The month of October heralds the onset of
autumn, the post-monsoon period. During this month, the South West Monsoon starts to
withdraw and there are intermittent spells of rain.
2.4.1 WEATHER PHENOMENAOF TRIPURA

7. The temperature shows declining trends from west to east. The daily maximum
temperature and minimum mean temperature are 30.70 °c and 19.50° c respectively during
summer months. The cold weather starts from about the end of the November when the
temperature of the body day and the night decreases steadily. January is the coldest month
when daily minimum temperature is only 8.9°c and maximum temperature is 25.°c.
A more sensitive element of climate is the variation in rainfall. It
varies not only from place to place or from year to year, but also between seasons. Annual
rainfall ranges from 1922mm to 2855mm. the rainfall generally increases from south west to
north east. There is a big gap in the rainfall in the southern central part around Amarpur,
which is surrounded by 1500mm most of the rain comes during the month of April-June and
july-sept. This period is generally referred to as Kharif season this is the major agriculture
season of the whole state. The factors governing rainfall are the seasonal changes in the
direction of the wind and the presence of the cool upper air current over the given parts of
the state.
2.7 DRAINAGE:
The State of Tripura is well endowed with surface water resources. All rivers are rainfed and
ephemeral in nature. All major rivers originate from hill ranges and show a typical drainage
pattern called trelis, except a few instances of dendrite pattern.Rivers originating in the hill
ranges can cause flood in heavy rainfall. Flood level of at least five of the major rivers show
that the danger may vary from 1.48 meter for Haora River near Agartala to 31.50 meter for
Dhalai river near Kamalpur.
There are 10 (ten) major rivers in the state. They are generally ephemeral in nature and
their flow is directly related to the rainfall, being in spate in rainy season and running almost
dry during summer months.
The purity and sustained and regular discharge of water is directly proportional to intensity
of vegetative cover in the river systems. Due to deforestation in the catchment areas of such
river systems all the navigable rivers have become almost dry during lean seasons. The
water are muddy during rainy season and bitterly polluted during lean periods.
The burima,gomati, khowai,howrah, longai, dhalai, muhuri, feni, juri, manu are
the major rivers .Besides, there are many small lakes and ponds in the state. There are as
many as 13 lakes inside trishna wildlife sanctuary, and 2 inside sepahijala wildlife sanctuary.
Many migratory birds visit these lakes. Special mention may be made of a clear water lake "
devtapukur" at the source of muhuri river which can be a beautiful tourist spot in future.
Gomati is the largest river. Like the Ganges in North India, the Gomati is
considered to be the most sacred of all the rivers in Tripura. The source of the river is taken to

8. be Tirthamukh where lies the beautiful Dumbar falls - one of the most important holy places.
The rivers Khowai, Doloi, Manu, Juri and Langai are flowing towards the north and those
flowing towards west are the Gomati, Muhuri and Feni
2.8 NATURAL VEGETATION:
Forest resources play significant role in both socio-economic development and environment
of any area. The Forest ecosystemis now known to serve a multiple function in absorbing
Carbon load, generation of oxygen, moderating climate, preventing soil erosion, recharging
Groundwater, etc. The forest in Tripura may be classified into three different types of
classificatory system.
A. Climatic Types
1. Evergreen forest
2. Moist deciduous forest
i. Sal forest
ii. Mixed forest
B. Seral Types
3. Swamp vegetation
C. Edaphic Types
4. Bamboo forest
5. Cane forest
6. Garjan forest
7. Savannah forest
8. Grass land vegetation

9. GEOGRAPHICALBACKGROUND (MAPS)

10. Fig. DRAINAGE MAP
Fig:
FOREST COVER

11. CHAPTER- III
PHYSICAL SET-UP OF THE STUDY AREA
(LOCATION)
Tripura is one of the states of north eastern India, lies at the (CTFB) Chittagong Tripura fold
belt. It is the 3rd smallest state of India and covers an area of 10,486 square km. nearly 70%
of the total area is hilly, leaving very little cultivable land. About 59% of the total area is
classified as forest and under the ambit of the Forest Conservation Act. Flood and droughts
are the normal phenomena of the state. The streams and rivers almost become dry during
winter season while in rainy season however, these are uncontrollable. Most of the rainfall
is received from April to September. Due to the heavy rainfall and undulating topography,
soil is susceptible to erosion. Erosion is influence by a number of meteorological and
environmental factors, such as the amount and intensity of rainfall, the degree, direction
and the length of the slope, vegetation cover, and inherent capacity of the soil to erode and
the bad management of cultivated lands.
3.1 LOCATION and EXTENT:
Tripura is located in the south-west extreme corner of the north-eastern region. Despite
being geographically the smallest state in the region, it is the second most populous state
after Assam, with a population density of 304 per Sq Km. Backwardness of the state arises
primarily due to its geographical isolation. This problem which is common to all north-
eastern states, assumes the most difficult dimension in case of Tripura. In the north-eastern
region, Agartala, the state capital, is located at the farthest distance from Shillong,
headquarter of the North Eastern Council (487 KM), as compared to other state capitals Of
the region.
Tripura has 84% of its border common with Bangladesh. Promotion of trade with
Bangladesh including border trade will open a vast market, which will in turn catalyse
development of agriculture and industry in the state.
3.2 SIZE:
As per the 2011 census, the population of the state is 36, 73,032. It constitutes around 0.3% of the
total population of the country. The indigenous communities that are known as ST (Scheduled
Tribes) in India form 30% of the population in Tripura.
Area 10,491.69 km2(4,050.86 sq mi)
Density 350/Km2
Total Population (2011) 3,671,032
Males Population (2011) 1874376
Females Population (2011) 1799541

12. 3.3 PHYSIOGRAPHY:
The Tripura was known as “Hill Tipperah highest” and the very nomenclature is suggestive
of its hill nature of undulating surface made uneven by inter-pressed low hills. The
physiography tends to flatten towards west. However, in some places the terrain is
inaccessible and highly undulating. The lungas(Longitudinal valley) lands are juxtaposed in
between the numerous Tilla(hillocks) Lands, which are the fertile agricultural lands. They are
well known for paddy cultivation and recharge capacity of groundwater resource. A series of
hills ranges running north south divide the terriorty into broad parallel valleys, consisting of
undulating tillas(hillocks) covered with jungles and meandering streams. There are six
principal ranges in the state increasing in height as one moves towards east. Of the six
ranges Baramura, Deotamura, and Atharamuar ranges partly falls within West Tripura.The
heightest point of the state is Betling Shib that is located in Jampui range. The altitude of
Belting Shib is 3,081 feet or 939 meters. The isolated hillocks that are scattered throughout
this state are called tillas. The narrow alluvial valleys that are located on the western side
are known as lungas. The alluvial plains of Tripura include the narrow valleys, locally known
as lungas, that lie mainly in the western part of the State. The lungas are fertile and rice is
cultivated here. There are very few flood plains in Tripura; they are mostly located in the
west and south, and form the main agricultural lands of the State.

13. 3.3.a PHYSIOGRAPHIC UNITS OF TRIPURA:
 Steeping slopping and slightly dissected high relief structural hills and ridges
exemplified by areas like Kailashahar, Panisagar, Baramura,Teliamura.
 Moderately slopping with moderately dissected medium relief parallel ridges
present in north and north eastern part of Tripura.
 Moderately to gently sloping and moderately dissected flat topped denuded
hill occurring in western, central and southern part of Tripura.
 Low lying residual hill with valley represented by gonda charra area of south
eastern Part of Tripura.
 Moderately to gently sloping inter-hill valleys with alluvial upland plains.
 Kumarghat-Chailengta area as alluvial deposit of river Manu.
Flood plain constitutes important area rerolled by rivers of Tripura.
3.4 GEOLOGY:
State of Tripura exhibit an wide array of sedimentary rocks characteristics of marine-mixed-
fluvial type origin ranging age from upper most Oligocene (38 million years from present
time) to Recent period, the Surma basin during Tertiary age (which lasted for 65 million
years) in an wide range of environmental conditions governed by local tectonic movement.
Tectonically, the region now comprises a series of sub-parallel arquate, elongated, doubly
plunging folds arrange in north south direction. These folds for anticlines separated by wide
flat synclines. Tripura forms part of the Tertiary Naga-ArakanYoma basin and is located to
the southwest of Palaeogene fold belt of Naga Hills. Neogene belt is broadly confined by
Haflong-Dawki Fault to north and Barisal Chandpur High to west and northwest. Post Barail
upheaval of Palaeogene sediments swallowed distal south-western part of the basin
wherein Neogene sediments of Tripura (Cachar-Mizoram) were deposited. Relationship
between Palaeogene and Neogene sediments in Tripura have not been established as Barail
Group is not exposed in Tripura. It is likely that Neogene sediments were deposited on the
folded, but not uplifted, Palaeogene sediments and were subsequently co-folded with the
latter.
The intensity of folding and structural complexities: increase  eastward. Sedimentation
and tectonic activity of the area: initiated from the  east and gradually migrated towards
the  west .

14. TABLE:
STRATIGRAPHIC LITHOLOGY AGE
UNIT
KHOWAI FORMATION - Alluvium valley fills sand, silt and clay recent
DUPLITILA FORMATION - mostly clay, consolidated to mostly
Unconsolidated sands, and silt containing
Ferruginous nodules.
TIPAM FORMATION - medium to coarse grained consolidated
To less unconsolidated current bedded sandstone
With fossils wood altering at places with siltstone. Pliocene
SURMA - BOKABIL FORMATION UPPER -predominantly thick pile miopliocene
FORMATION
of thin bedded grey shale, mudstone
And siltstone occasionally altering with
Sandstone bands.
BHUBAN FORMATION UPPER- grey siltstone andsoft sandstone, Oligomiocene
Often micaceous.
LOWER- well bedded hard grey sandstone,
At places altering with siltstone. Barails not eXposed.
SOURCE: NRSA (1979) - national remote sensing agency.
3.5 CLIMATE and WEATHER:
The climate of Tripura isinfluencedbyitslocationinthe northeasternpartof India.The climate in
Tripura displays characteristics that are typical of the hilly and mountainous region. The
change in the topographical features of the region also causes a change in the climatic
conditions in Tripura. The state of Tripura influences a monsoonal climate with the well
demarcated sub tropical and temperate zones.

15. The state of Tripura influences four distinguishable seasons. Summer, monsoon, autumn
and winter.
I. WINTER SEASON :DECEMBER TO FEBRUARY (cold)
II. PRE- MONSOON : MARCH TO APRIL (HOT)
III. MONSOON : MAY TO SEPTEMBER( rainy)
IV. RETREATING MONSOON: OCTOBER –NOVEMBER
From the month of March the day and night temperatures rise rapidly, the highest
temperature being in April. During this hot spell strong winds are experienced, sometimes
accompanied by thunderstorms. By the end of May, the south West Monsoon arrives, giving
respite to all. Temperature drops, more than sixty per cent of the annual rainfall takes place in
the summer months, from March to May, when there are thunderstorms. The post-monsoon
period. During this month, the South West Monsoon starts to withdraw and there are
intermittent spells of rain. Both day and night temperatures decrease slowly. By the end of
November, winter sets in. day and night temperatures slowly but surely start to decrease.
January is the coldest month in Tripura during which time the temperature hovers between
25.5 and 10.4°C. The state records an average annual rainfall of 2100 mm. Kamalpur in
Tripura receives the maximum amount of rainfall of 2855 mm while Sonamura receives the
lowest average of 1811 mm.
Humidity is generally high throughout the year. In the summer season the relative humidity
is between 50% to 74%, where as in the rainy season it is over 85%.
3.6 DRAINAGE:
Rivers are natural water bodies having various beneficial uses for mankind. Each valley
contain a stream, in which smaller hills streams join, carrying ware from the hill side and
follows all sorts of directions. The hills and the hill slopes are well drained but the valley
with very little slope mostly suffer from impeded drainage are marshy and in the lower
contours are logged and swampy. The flow in a river helps in dilution of effluents and in self
purification. The drains are divided into three categories – ‘high’, ‘medium’, & ‘low’. This is
done to differentiate the different drains according to their dilution capacity, which may be
based on the flow characteristics in a particular district. In Tripura there are no rivers having
high flow. The State is drained by as many as 10 rivers which originate in the hill ranges and
flow either in a northerly or westerly direction through the narrow valleys. These rivers are
Longai, Juri, Deo, Manu, Dhalai, Khowai, Haora, Gomti, Muhuri and Fenni.However, all rivers
are rain-fed and ephemeral in nature, their flow is directly related to rainfall.
3.5. a Name of the River (Origin& Flow)
1. Longai river - Jampui Hill Northerly flow 98 km long.
2. Juri river- Jampui Hill Northerly flow through Dharmangar valley.

16. 3. Deo river- Jampui Hill Northerly flow through Kanchanpur valley, meets Manu
River 98 km long.
4. Manu- Sakhan range Northerly flow via Kailasahar to Bangladesh 167 km long
5. Dhalai- Longtharai range Northerly flow via Kamalpur to Bangladesh 117km
Long
6. Khowai- Longtharai range North-west flow and then northerly via Khowai town
To Bangladesh 70km long
7. Haroa- Baramura range Westward flow via Agartala to Bangladesh 53 km long
8. Gumti- Longtharai and Atharamura range Flow westward via Amarpur,
Sonamura to Bangladesh
9. Muhuri-Deotamura range Westward flow via Belonia to Bangladesh 64 km long
10. Fenni- Originate at the border by confluence of three streams, of which
As along is the main channel.
The Drainage pattern in the state is in conformity with the topography, supporting
the sub parallel drainage system. The Anticlincal hill ranges forms watersheds from which
the various drainage channels emerge. The common drainage patterns in the state are of
dendritic parallel to sub parallel and rectangular type and are of 1st order and 2nd order. The
major rivers of the state are Gumti, haora, khowai, manu, deo feni, and mahuri. The
drainage system of the state forms a part of Meghna Basin. Trellis drainage pattern is also
observed in few places.
3.7 SOIL:
The soil may be considered as an aggregate of solid particles separated by air and water. But
it is also important factors in determining the climate. Dark coloured soils and surfaces
absorb more of sun’s heat than the lighter coloured ones. The study of soil types enables us
to make quantitative estimation of infiltration in the soil, water storage capacity,
percolation, and surface and sub surface run off, traction ability of the material and plant
growth. Soils develop as a result of the interplay of 5 factors; Parent material, Climate,
organisms, relief and time. Relief is not static; it is a dynamic system. Relief influences soil
formation in several ways. It influences soil profile thickness i.e. as angle of slope increases
so Does the erosion hazard. It has an effect on climate which is also a soil forming factor
Gradient affects run-off, percolation and mass movement; it influences aspect which creates
microclimatic conditions. The soil types of Tripura can be classified under five major groups,
of which Red loam and sandy loam soil occupies 43.07 percent of the total area followed by
Reddish yellow brown sandy soils (33.06%), the other three groups occupy less than 10
percent each.
Types of soil:
3.6a Reddish Yellow Brown sandy Soil:
This soil type covers nearly one third of the total geographical area of the State, mostly

17. Distributed along north south axis. Poor in nutrient, the sandy soil due to leaching under
Heavy rainfall, the soil type shows a resilience process through utilization of ground biomass
of Leaf litters. Tropical evergreen forest of Tripura largely grow in sandy soil but clear felling
of Trees in the hill forest can cause serious erosion problem to these soil resources.
3.6b Red Loam and sandy Loam:
About 43-45 percent of total geographical area of Tripura is covered by the red loam and
sandy loam soils. Such soil is normally associated with forest ecosystem and is rich in
nutrient. In heavy rain fall area, such soil is prone to heavy erosion, especially in slope areas.
3.6c Older Alluvial Soil:
About 10 percent of the State is covered by older alluvial soil. Normally located in river
terraces and high plains, the soil is rich in organic nutrient and suitable for arable farming.
Much of older soil however remains under tropical forest cover. Due to possibility of gully
erosion in uplands, slopes and river terraces, older alluvial soil need special soil conservation
measures.
3.6d Younger Alluvial Soil:
About 9 percent of the State of Tripura is covered by younger alluvial soil, confined to the
flood plains of river (e.g. Khowai, Haora, Gumti and Muhari, etc.). This composed of clay
loam and loam and is extremely rich and fertile due to impact of annual flooding. While
assured cultivation of Jute and Paddy in such soil regime is known, the danger of erosion by
lateral cutting and bank collapse has to be kept under consideration to avoid wash-down to
Bangladesh plains from the State of Tripura.
3.6d Lateritic Soil:
Along the western boundary, recognise upland with lateritic soil can be recognized.
Approximately 5 percent of the total land in Tripura can be classified under “lateritic soil”.
Coarse in texture and very poor in nutrients, this soil type can support scrubland and wild
Bushes.
TABLE:2

18. 3.8 NATURAL VEGETAION
Climate is the chief control of vegetation types, but they also influence the climate. The
vegetation affects differential absorption of incoming isolation, interferes with air motion,
increases the area to be heated and increases the moisture content in the air as a result of
transpiration. Of the total geographical area of the State of 10,486 sq. km, a total of 6292
sq. km is recorded as forest. The actual forest cover is however is estimated at 5745 sq. km,
constituting 54.78 percent of the total geographical area. Of this, 2228 sq. km is considered
dense forest; 3517 sq. km is recorded as open forest and scrub forest, leaving 4741 as non
forest- area. Forests in the state are mainly tropical evergreen, semi evergreen, and moist
deciduous. Sizeable area is covered with bamboo brakes which virtually form a “Sub climax”
resulting from shifting cultivation from time immemorial.
1. Types of forest:
1. A Evergreen Forest
Characterized by stand in distinct three tier evergreen forests exhibit numerous species of
Trees, with high biodiversity but none of the species may be abundant in population.
Evergreen forests can be seen in Dharamnagar and Kailashahar area, Jampui and Sakhan hill
ranges,and in part of Belonia, Sabrum, Kamalpur and Sadar sub-division. Species of
Dipterocarpus, Artocarpus, Amoora, Elaeocarpus, Syzygium,Eugenea dominated the top
canopy.
1. B Moist Deciduous Forest
1. B.i.Sal forest
The dominant species, Sal or Shorea robusta provides more than 60% of the top canopy in
this type of forest. Found in southern and northern low hills, extending up to the border of
Bangladesh, Sal forest has undergone significant changes in some areas like Sonamura, due
to expansion of paddy cultivation. Locally, Sal forest can still be found in Belonia,
Udaipur,Sonamura and part of Sadar sub-division.
1. B.ii Moist deciduous Mixed Forest
Characterized by absence or scarce, Sal trees, mixed forest offer dense and even canopy
reaching a height of as long as 25 meters. Such forest can be seen in Amarpur, Sonamura,
Udaipur and Sadar areas and in fragmented patches in Dharmanagar, Kailashsahar and
Kamalpur areas.
1. C Bamboo and Cane Forest
Large tract of land in forest area show bamboo forest, often interrupted by evergreen or
deciduous secondary stand. Abandoned Jhum land appear favourable for natural bamboo
growth besides sheltered hollows, etc. Cane grows extensively in the wet hollows and
amidst evergreen, semi-evergreen and moistdeciduous forest. Species of Calamus (guruba,
floribundus, ertectus, leptospadix, vimnialis) dominate the thorny thickets.
1. D Garjan Forest
It is basically a part of evergreen vegetation, and sometimes associated with Sal trees of
moist deciduous forest. Garjan or Dipterocarpus furbinatus forms the dominant species in

19. these forests occuring in Khowai, Muturi, Talatalikona, Chailengta, Deo, Dharmanagar,
Jalaya and other areas.
1. E Grassland
Grasslands are formed as an edaphic climax on wet soils. Besides the natural grassland,
grassland succeeds activities of shifting cultivation, forest fire and areas of other human
activities. Aquatic grasses often occupy silted marshland enriched by silt and organic debris.
1. F Swamp Vegetation
Swamps cover a large part of the geographical area of the State. The swamp areas harbour
harbaceous species, few shrubs and trees dominated by Albizia, Baringtonia, Lagerstroemia,
Macaranga, Mullotis species; herbs and grasses include Clinogyne, Phragmites and
Saccharumspecies.
Forest forms one of the basic source of revenue in Tripura. Once
Tripura was very rich in forest wealth but due to the practice of shifting cultivation
continuously destroyed it. Refugee’s influx had also impact on the forest. Bamboo(muli) is
one of the major vegetation cover associated with densely with ‘san’ and ‘kas’ grasses
which are about 1.8 m high, typic of tarai of Himalayan range. Bamboos are of dwarf variety
and are used mainly for paper pulp and umbrella making. The rich field ‘sal’ is mainly found
in the north sonamura, karchakhola and south sonamura block. The principal deciduous
trees like segun, karai, hargaja, gamair, and wild neem are quite common.bontulsi is found
in abundance associated with ‘san’ and ‘kas’ grasses. In the alluvial tract, kul,palm, date
palm, are common. Mangoes, lichies, jackfruits, blackberries also occupy a good area. In the
steepe slopes pineapple grows in abundance. Besides this, wild banana is also very popular
in the hilly tract of the region.
3.9 AGRICULTURE:
Two types of agriculture practises are very common, a. The usual method of growing aman
and aus paddy and jute in the alluvial tract. B.Shifting cultivation in the upland called
jhumming. Agriculture is the main stay of the people, the land can be divided into three
catogries:
1. Jhum land on steep slope of the hillocks
2. Tilla land
3. River valleys or lungas.
In the flat tillas (uplands) kharif is the amin crop i.e rice, cotton, turmeric, ginger,
maize,and kharif vegetation etc. Are grown where as mustard, paddy , potato, and
winter vegetables are the important rabi crops.In charalands (medium land) refined
wheat, pulses, and oil seeds are becoming popular among farmers.
The state has favourable climatic conditions for cultivation of various fruit and horticultural
crops. It is rich in natural resources such as natural gas, rubber, tea and medicinal plants.
Tripura is endowed with rich and diverse bamboo resources. It is also the second largest

20. natural rubber producer in the country after Kerala and produced 37,277 million tonnes of
rubber in FY 15. Tripura accounts for about 6 per cent of bamboo sticks, used for making
incense sticks in India. Around 21 of the 130 bamboo species known in India are grown in
the state. Tripura holds a strong tea plantation base, with 58 tea gardens covering an area
of over 7,000 hectares in 2014-15. Tea produced in Tripura is famous for its blending
qualities. The good agro-climatic conditions, deep fertile soils, subtropical humid climate
with abundance of rainfall offer tremendous scope for development of Horticulture sector
in the state. Rice is the major crop of the state and is cultivated in 91 per cent of the
cropped area. The state has a wide variety of medical plants having 266 medicinal plants,
379 species of trees, 581 herbs, 320 shrubs and 165 climbers.
Fig. LOCATION MAP OF TEH STUDY AREA (not to scale)
INDIA

21. FIG: LONGITUDNALand LATITUDNALPROFILES
Fig: GOOGLE MAP OF TRIPURA

22. Fig: DIGITAL ELEVATIOIN MODEL (TRIPURA)
NORTH

23. Fig: land use land cover of the STUDY AREA

24. CHAPTER-IV
Thermal characteristics of the study area (temperature)
Temperature is an independent variable among the climatic elements. Temperature
variation causes corresponding changes in the pressure distribution and consequently in
wind direction and its velocity which controls atmospheric humidity, condensation,
formation of clouds, and their drafting in the sky, precipitation, and storms. Either directly
or indirectly controls the weather elements.
As far as study of climate of an area concerned temperature holds the
key position because it determines the character of the local climate. Hence it becomes
importance to analysis of temperature variations of aits areal and seasonal distribution,
annual variation of its magnitude, temperature anomalies, ranges and extremes. Spatial
variation in temperature is importance as temporal variation. The atmosphere is heated or
cooled by the process such as conduction, convection, terrestrial radiation, latent heat of
condensation.

25. Year (MAX) TEMPERATURE °c (MIN.) TEMPERATURE
1901 28.83039583 17.12739583
1902 28.57079167 16.83202084
1903 28.76135417 17.10114583
1904 28.57120833 16.85316667
1905 28.44389583 16.94633333
1906 28.86610417 17.28633333
1907 28.6643125 16.98295834
1908 28.86952083 17.13
1909 28.952 17.23916667
1910 28.09260417 16.27954167
1911 28.1675625 16.3470625
1912 28.53689583 16.81670833
1913 28.425125 16.5858125
1914 28.45327084 16.88947917
1915 29.02602083 17.45845833
1916 28.42045833 16.85604167
1917 28.11591667 16.4863125
1918 28.32214584 16.6749375
1919 28.69520834 16.94483334
1920 28.641875 17.0053125
1921 28.58235417 17.0919375
1922 28.77841667 17.34210417
1923 28.75377083 17.185625
1924 28.70958334 16.97825
1925 28.01504167 16.5700625
1926 28.44229167 17.3090625
1927 28.44639583 16.94322917
1928 28.89347917 17.285625
1929 28.39566667 16.80152083
1930 28.39825 16.91383333
1931 28.18166667 18.07535417
1932 28.33135417 17.9246875
1933 28.23245833 17.13560417
1934 28.1534375 17.46022917
1935 28.46345833 16.54977083
1936 28.3608125 17.54475
1937 28.27764583 17.33039583
1938 28.525625 17.667125
1939 28.77685417 17.959625
1940 28.58452083 17.55552083
1941 28.65579167 18.35752083
1942 28.31422917 17.20375
1943 28.23802083 16.9244375
1944 28.44625 17.27916667
1945 28.49252083 16.95235417
1946 28.93120833 17.3774375
1947 29.0063125 17.782625
1948 28.63652083 17.19479167
1949 28.21075 15.95722917
1950 29.13172917 16.99270834
1951 29.23966667 18.30216667
1952 28.93035417 17.5284375
1953 29.55966667 18.01241667
1954 29.10235417 17.43935417
1955 28.8881875 16.77691667
1956 29.14252083 17.05575
1957 29.40120834 16.6131875
1958 29.5478125 17.66841667
1959 28.94920833 16.59441667
1960 29.22658333 17.15722917
1961 28.8443125 15.709
1962 29.186 16.2786875
1963 29.04610417 16.9791875
1964 28.92839583 17.56
1965 28.94175 17.80125
1966 28.87491667 17.34552084
1967 29.12464584 16.80002083
1968 28.91652083 16.65020833
1969 28.93720833 16.77333333
1970 28.7611875 17.055875
1971 28.45754167 16.23970833
1972 29.08464583 16.91675
1973 28.09241667 17.37016667
1974 27.99652083 16.42533334
1975 28.40045834 16.60727084
1976 28.38541667 16.90445834
1977 28.04197917 17.26110417
1978 29.10714583 17.04875
1979 29.00564583 18.52254167
1980 29.16270834 17.994625
1981 28.63660417 17.35764583

26. 1974 27.99652083 16.42533334
1975 28.40045834 16.60727084
1976 28.38541667 16.90445834
1977 28.04197917 17.26110417
1978 29.10714583 17.04875
1979 29.00564583 18.52254167
1980 29.16270834 17.994625
1981 28.63660417 17.35764583
1982 28.683875 17.24060417
1983 28.56229167 17.5659375
1984 28.9306875 17.17075
1985 29.18727083 18.3211875
1986 29.27139583 17.4926875
1987 29.5729375 17.51464583
1988 29.43095833 18.64310417
1989 28.79695834 17.1141875
1990 28.56366667 18.80647917
1991 28.74064584 17.12608334
1992 28.79977083 16.99554167
1993 28.9611875 17.5743125
1994 29.05654167 17.37604167
1995 28.82445834 17.51095833
1996 29.29220833 17.57497917
1997 28.61889583 18.62445833
1998 29.23747917 18.94460417
1999 29.42935417 19.23695833
2000 28.65460417 17.5758125
2001 29.15597917 18.23879167
2002 29.4648125 17.9295
2003 30.47639657 20.27302099
2004 31.11527036 20.51783927
2005 30.81713134 20.91027842
2006 32.07155914 20.58370072
2007 30.35946557 20.35022849

27. MEAN ANNUAL (MAXIMIUM) TEMPERATURE

28. TABLE 3 MEAN MONTHLY MAX.and MIN. TEMPERATURE
MONTHS Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1901 MAX 24.9335 27.1195 29.714 31.3525 30.65675 30.02375 29.53725 29.63075 29.95325 29.942 27.658 25.73125
MIN 11.51375 14.367 18.93225 23.628 24.129 25.481 25.32975 25.19775 25.239 23.805 18.05775 13.461
1930 MAX 23.72225 27.561 30.4785 32.00625 31.791 30.0115 30.5205 30.17075 31.346 30.14825 28.16175 25.66025
MIN 10.717 14.42175 19.22725 22.58825 24.3455 24.5545 24.9815 25.19575 26.07925 22.97925 18.611 13.244
1960 MAX 25.55375 29.84625 31.4155 35.0045 34.33525 31.15425 29.421 31.401 30.98175 30.99825 28.171 26.13525
MIN 11.32925 13.6685 17.37975 23.12375 24.82375 25.03075 24.76525 25.20075 24.5235 23.04075 17.5435 13.72775
1990 MAX 25.4985 27.19725 27.794 30.76875 32.38625 31.32975 29.967 30.92575 31.03825 29.6915 29.426 26.338
MIN 13.876 16.4245 19.227 22.27675 25.08975 25.9965 25.13125 25.3285 25.75625 23.10775 21.82075 15.90325
2007 MAX. 24.75161 27.58929 31.46452 32.8 33.65387 31.58667 30.99032 32.62903 32.12333 31.45161 29.30667 25.96667
MIN 9.832258 14.775 16.98065 22.55 24.59161 25.10667 25.37097 25.77419 25.51667 22.65806 18.59667 12.45

29. TABLE: 4 (MEANMONTHLY TEMPERATURE VARIATION OF 30 YEARS)
MONTHS/YEARS Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1901 24.6875 27.6325 30.95625 33.19725 32.32 31.42475 30.74125 30.83825 31.307 31.3345 28.3225 25.73125
1930 23.72225 27.561 30.4785 32.00625 31.791 30.0115 30.5205 30.17075 31.346 30.14825 28.16175 25.66025
1960 24.6605 28.79575 30.886 33.566 33.06925 30.565 29.97875 30.77275 31.13925 30.568 28.146 25.95125
2007 24.7 27.58 31.46 32.8 33.65 31.58 30.99 32.62 32.12 31.45 29.3 25.96

30. TABLE: DISTRICTS- WISE TEMERATURE VARIATION ON THE BASIS OF RELIEF

31. Year NORTH TRIPURA WEST TRIPURA
1901 25.383 30.07333333
1930 25.373 29.51
1960 25.607 30.54133333
1990 25.776 29.51141667
2002 26.672 30.499

33. 1951 317.240125
1952 357.6335833
1953 260.0302917
1954 263.6517292
1955 224.1613542
1956 266.7401042
1957 224.9125
1958 218.8428958
1959 277.61425
1960 220.7487917
1961 210.99425
1962 185.9613542
1963 194.9043958
1964 326.1983125
1965 255.2553333
1966 242.0855209
1967 182.8902292
1968 221.4536667
1969 260.2437708
1970 192.3492708
1971 140.9546667
1972 154.4183334
1973 209.6338125
1974 274.1691459
1975 183.6659583
1976 207.2308542
1977 214.46375
1978 180.6731667
1979 164.3055
1980 206.9530417
1981 228.2052083
1982 215.0177084
1983 239.2140625
1984 251.5277708
1985 174.237375
1986 193.7434792
1987 196.4415833
1988 238.888
1989 168.4689167
1990 199.4595208
1991 223.5019375
1992 205.6720417
1993 250.80875
1994 195.756125
1995 200.5540834
1996 225.4243958
1997 201.3114583
1998 236.9313125
1999 188.8933542
2000 199.1844167
2001 218.3510208
2002 230.4673125
2003 210.5
2004 251.5
2005 192.79
2006 244.43
2007 292.5
Year RAINFALL
1901 217.3755833
1902 222.6235833
1903 211.632375
1904 198.5139583
1905 261.6976042
1906 206.9750625
1907 189.6280625
1908 169.3093125
1909 190.8048959
1910 223.6688333
1911 257.359375
1912 218.5006875
1913 230.8185625
1914 199.3683125
1915 253.4792709
1916 268.0604792
1917 206.8825
1918 228.9027292
1919 209.3283959
1920 193.4565834
1921 237.7862708
1922 219.4884583
1923 197.264125
1924 248.4759792
1925 192.2025417
1926 203.1572084
1927 211.5350625
1928 218.4851875
1929 219.9887083
1930 217.5752292
1931 211.0226458
1932 253.5265834
1933 202.9936875
1934 245.0513333
1935 200.4131042
1936 224.1913958
1937 193.5251667
1938 269.8418334
1939 223.0959584
1940 205.4594584
1941 226.203125
1942 209.5605
1943 209.7445833
1944 190.0744583
1945 208.3199375
1946 221.6101875
1947 272.3912292
1948 306.1508333
1949 342.5568958
1950 204.935625
TABLE: MEAN ANNUALRAINFALLin(cm)

34. Fig:
ANNUAL MEAN RAINFALL OF 30 YEARS

35. TABLE : MEAN ANNUALRAINFALL in (cm)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1901 17.66675 17.6915 15.12175 215.3293 260.5508 442.3423 413.1753 416.7105 341.7 256.9408 209.9038 1.3745
1930 7.727 18.62625 42.0035 83.775 317.6733 604.5828 364.9638 625.012 206.9563 121.7595 216.536 1.2875
1960 0 0.73475 43.536 39.8495 319.9168 438.978 746.2783 391.5623 464.9925 142.2358 60.22475 0.677
2007 0 45 7 458.6 298.1 637 787 207.3 136.2 232 116.9 0

36. TABLE : ANNUALRAINFALLDISTRICTWISE
NORTH TRIPURA WEST TRIPURA
Year
1901 221.45075 201.0423333
1930 219.327 199.9711667
1960 225.6165 200.2968333
1990 206.298 186.0444167
2002 238.266 214.2190833