Geoenvironmental Changes in the Northern Part of Atharamura Hill Ranges and it’s Impact on this Area

 

Mandira Shaw

Guest Lecturer of Shirakole Mahavidyalaya, Shirakole, South 24 parganas, Pin-743513, West Bengal, India

*Corresponding Author Email: mandirashaw01@gmail.com

 

ABSTRACT:

Geoenvironment factors or properties of the landscape like topography, drainage network. soil erosion, rockmass strength are more significant in identifying the cause of degradation. This region has great geological and geomorphological peculiarities, beyond being a place with large human interventions because of its quickly economic growth. Geoenvironment zones were obtained from a weighted integration by multieriteria analysis of physiographic units with land-use classes.

 

KEYWORDS: Village wise population, land use changes in different year, conclusion.

 

 


1. INTRODUCTION:

Geo-environmental change of the northern part of Atharamura hill ranges are most crucial events which causes high loss to the environment as well as socio-economic setup of this area. Geo-environmental change take place of the northern part of Atharamura hill ranges by Anthropogenic caused like hill slope cutting, jhum cultivation, forest cutting, road construction, destruction of tilla- lungaetc and it causes natural disasters & hazard (land slide, soil erosion).

 

Tripura State lies in the eastern part of India, bordered by Bangladesh to the west, south and north, by Assam to 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 Assam and rest of the country through the adjoining Cachar district, lying to the northeast. There are many rivers in the state which rise from the six principal hill ranges and, after being fed by innumerable small cherras, flow through the valleys into the mighty rivers of East Bengal.

 

They are fed only by rain water and most of them drying up during winter and swelling dangerously during monsoons, causing destructive flood.

 

Northern part of Atharamura hill range area is my study area. It belongs to the northern part of Dhalai. Total geographical area of this district is 19745 ha. In 19745 ha, 11327ha fall in forest area that is indicated this region is very reach in vegetation cover.

 

Location of study area:

Total geographical area of my study area (northern part of Atharamura hill range area) is 235 sq. miles. It is situated between 24° 14ˊ47.95ˊˊ north to 23° 49ˊ08.77ˊˊ north and 91° 44ˊ37.67ˊˊeast to 91° 57ˊ52.88ˊˊ and it is surrounded by the Bangladesh, West Tripura district, Manu and Chamanu sub district of the Tripura.

 

Importance of the study:

The purpose of the inventory is to collect information that will help in understanding the change of the geo-environment of the northern part of Atharamura hill ranges, timing and what area the processes take place in this area.

 

This understanding will guide the creation of a land use, Landover map, Identification Information of what type of geo-environmental changes take places, triggering factors etc.

2. PROBLEM OF THE STUDY:

·       Firstly, geo-environmental changesare needed to beidentified, and find the causes of the changes.

·       The changes in geo environmental condition are due to anthropogenic factors or natural.

·        Impact ofgeo-environmental change on socio economic setup of the concerned area.

 

3. OBJECTIVE:

·       To identify the nature and extent of geo-environmental changes in the study area.

·       To analyze the impact of such changes on the nature and extent of land use/land coverchanges in Northern part of Atharamura hill range area during the last 30 years.

·       To assess the impact of such changes on the socio-economic set-up of the study area.

 

4. MATERIALS:

Data from the individual parameters have been generated from the multi-temporal satellite data set observed by thematic mapper (TM) Landsat 5, Landsat 7, Landsat MMS satellite data, SRTM satellite data, survey of  India toposheet map drawn on 1:63360 scales , Google earth map, thematic maps prepare by ICAR, watershed map prepare by Tripura Space Applications Centre.

 

5. PARAMETERS:

Although different physical and anthropogenic parameters are responsible for geo-environmental change of Atharamura hill ranges but for the present study few parameters have been considered due to lack of time: land use, land cover, vegetation cover, rive migration characteristics, climate changes, occurrence of drought, population changes etc.

 

6. METHODOLOGIES:

The present work is an attemp:t to focus into the geo-environmental impact on the Northern part of Atharamura hill ranges. Any study relating to explore the historical and analytical perspective of a given sector needs to rely on collection of information in a scientific manner and analysis of the same using tools widely recognized and effective in social science. In order to reach the desired goal of the dissertation, survey has been conducted in two Blocks of Dhalai district in Tripura that is Ambassa and Salema Block, Salema.The study is mainly based on the secondary data collected from various offices and departments. For doing this each of the sub-division are considered as strata. From each strata sample tappers are selecting using the random sampling. The secondary source of the information were different official documents, rules and regulations published by the different Government and semi government organizations and such other institutional documents relevant to the present study. This is also enabled talking about the objective of this study to arouse people’s interest as well as cooperation. Google maps of various years are taken into concern to locate the various changes in the geo environmental changes in the area.

 

7. VILLAGE WISE TOTAL POPULATION DISTRIBUTION MAP OF AMBASSA:

The above map shows the total population distribution and male female distribution of the Ambassa Block. Purbanalicharra acquires the highest population in the block with the population ranging from 6597 to 8246. The second highest populated area is Kamalcharra and Kulai with the population range of 4948 – 6596 persons. Kanchanpur, Bagmara, Balarampur, Shikaribari is on the 3rd zone, Lalcharra on the 4rth and rest all the villages lies in the 5th zone of population where the population ranges from 0 to 1459 persons. Thus we can make out that Purbanalicharra is the most densely populated village of the Block and the male and female population of that area is equal.

 

 

Fig:1 Village wise population distribution

 

The above map shows the total population distribution and male female distribution of the Ambassa Block. Purbanalicharra acquires the highest population in the block with the population ranging from 6597 to 8246. The second highest populated area is Kamalcharra and Kulai with the population range of 4948 – 6596 persons. Kanchanpur, Bagmara, Balarampur, Shikaribari is on the 3rd zone, Lalcharra on the 4rth and rest all the villages lies in the 5th zone of population where the population ranges from 0 to 1459 persons. Thus we can make out that Purbanalicharra is the most densely populated village of the Block and the male and female population of that area is equal.

Land use and land cover change is a major issue in Tripura as well as Northern part of Atharamura hill range area.

 

“Land use refers to man’s activities and the varied uses which are carried on over land and land cover refers to natural vegetation, water bodies, rock/soil, artificial cover and others noticed on the land”-- (NRSA, 1989).

 

Land Cover, defined as the assemblage of biotic and a biotic components on the earth’s surface is one of the most crucial properties of the earth system. Land cover is that which covers the surface of the earth and land use describes how the land cover is modified. Land cover includes: water, snow, grassland, forest, and bare Soil. Land Use includes agricultural land, built up land, recreation area, wildlife management area etc.

 

Table 1: Spatial data sources

Data

Observation Time

Special Resolution/Scale

Landsat-TM

1975-03-26

30m

Landsat-TM

1989-02-22

30m

Landsat-TM

2006-12-06

30m

 

The Land cover reflects the immediate picture of the earth’s surface. It is shows that soil material, vegetation, and water. Land use refers to man's activities on land which are directly related to the land. Land use/ Land cover changes also involve the modification, either directly or indirectly, of natural habitats and natural phenomena on their ecological area. It is also influence to change eco-system of the affected area.

Multi-temporal satellite data set observed by LANDSAT 5 Thematic Mapper (TM), and Survey of India Toposheet map drawn on 1:63360 scales were used for the analysis. The resolution is 30 meters/pixel. Digital land use / land cover classification through supervised classification method, based on the field knowledge is employed to perform the classification ILWIS, Global mapper are tools using for extracting the land use, land cover layer, from Landsat TM. The land use land cover classes include danced forest, degraded forest; agriculture land, water bodies and cloud cover areas.

 

8. RESULT AND DISCUSSION:

Northern part of Atharamura hill ranges area cover with forest. It is the main natural resource of that area. The findings of the present investigation are presented. Most of the forest lands are dense forest. But day by day forest lands are degraded and converted to degraded forest, build up (settlements, road,) and agricultural land. According to SOI toposheet in the year 1932 forest covered almost 80 per cent of the study area. This has decreased to 68.55 per cent in1975 Land Sat (TM) Imageries, 53.67 per cent in 1989 (Land sat, TM data) and 30.29 per cent in 2006 (Land sat, TM data). It is observing that in the 31 years almost 38.26 per cent of the forest lands have got transformed to degraded forest, Agricultural land and Built-up land. Because of human, forest land got converted to forest Plantation, agricultural land, Settlement and Road etc.

 


 


  

 


Fig 2: Land use Land cover map of northern part of Atharamura hill range area from Landsat TM (136/043;1975.1989, 2006; band-3

 


 

Table 2: Northern part of Atharamura hill Area under land use and land cover

 

1975

1989

2006

Sl. No.

Land use /Land cover

Area (Sq.km)

%

Area (Sq.km)

%

Area (Sq.km)

%

1.

Dance Forest

414.81

68.55

324.77

53.67

217.26

30.29

2.

Degraded Forest

117.44

19.41

147.13

24.31

183.05

35.90

3.

Agricultural Land

52.65

8.7

98.61

16.30

160.78

26.57

4.

Water Body

20.24

3.35

34.64

5.72

44.06

7.28

 

Total

605.15

100

605.15

100

605.15

100

 

 



Fig 3: Distribution of land use / land cover in the study area

 


Agriculture land occupies rice are the major agricultural crops and other important fruit are pineapple; watermelon, banana. In the year 1975 the dance is about 68.55 % whereas degraded forest is 19.41% agricultural land 8.7% and water body is only 3.35%, as marked in my study area. But the rates of all these categories are marked to be increasing in the passage of time. That is in the year 1989 and 2006. In 2006 and in 1989 the percentage of dance forest decreased and this result in the gradual rise in the percentage of degraded forest, agricultural land and water bodies.

 

Northern part of Atharamura hill ranges plays a vital role in environment as well as on climate of Tripura (Dhalai). From the Atharamura hill ranges, two important rivers i.e. Dhalai & Khowai originates. The major land use Atharamura hill ranges is forests. But the land under forest cover has declining trend in the past 31 years. Here dense forest land converted to degrade forest, Agricultural land, Built-up land due to human activity. Due to loss of dense forest, stability of soil decrease and the erosion of the soil increasing trend day by day, result sedimentation load increasing in the river bed, river channel depth decreasing, water holding capacity also decreasing. due to this cause, system will be dis-balance. And we will lose our natural ecosystem and biodiversity also. The increase in agricultural land is a welcoming trend. The increase in the area under degraded forest, agricultural land, may lead to a lot of environmental and ecological problems. To sum up it could be stated that Northern part of Atharamura hill ranges one of the major biodiversity zones of the state of Tripura. Hence government should come forward to take initiative measures to protect the land under forest in Northern part of Atharamura hill ranges. Here proper land use planning is needed otherwise we may lose our natural resources that is forest.

 

9. REFFERENCE:

1.      Nandi (2001)on which he showed the details of the geological structure and the bedding structure of the north east India & Tripura.

2.      Bandopadhyay, De andSaha (2012) this paper I can know the details procedure of the Channel Planform Change & natural and anthropogenic impact on it.

3.      Prakasam.C, This paper describes the land use and land cover change with the help of remotesensing. From this paper I can know how to extract the land use and land cover from the TM bands.

4.      Kotoky, Bezbaruah, Baruah and Sarma, This paper describes the details of the riverbank erosion and how it occurs.

5.      Yellowstone River Channel Migration Zone Mapping Preparedfor: Custer County Conservation District Yellow stone River Conservation District Council. From this book I have studied about the river migration.

 

 

 

Received on 11.09.2018         Modified on 26.09.2018

Accepted on 03.10.2018      ©AandV Publications All right reserved

Res.  J. Humanities and Social Sciences. 2019; 10(1):140-144.

DOI: 10.5958/2321-5828.2019.00023.8