Journal of Global Resources
Volume 6 (01)August 2019-January 2020
Page 38-42
UGC–CARE Listed Journal in Group D
ISSN: 2395-3160 (Print), 2455-2445 (Online)

06
EFFECT OF CHANGING VEGETATION COVERAGE AND TEMPERATURE ON THE
MONSOON PATTERN OF INDIAN SUNDARBAN REGION
Papia Guha1*, Pritam Aitch2 and Gupinath Bhandari3
1
Research Scholar, 2,3Associate Professor
Department of Civil Engineering, Jadavpur University, Kolkata, West Bengal, India,
Email: guhapapia76@gmail.com, pritamaitch@gmail.com, g.bhandari.ju@gmail.com
Abstract: Sundarban, the grand symphony of nature at the confluence of Bay of Bengal covers
an area of about 25,500 sq. km. The Present study is over Indian Sundarban Delta (ISD)
covering an area of about 9,630 sq. km. ISD is known for its immense biological diversity andits importance for protecting West Bengal from natural hazards and changing climaticconditions. But the constant changes in atmospheric and ecological structure have disrupted
the region by changing the pattern of precipitation. Henceforth, the study is made to depict thereason behind such changes. Vegetation cover change is being detected by analysing imagesof Landsat USGS using Remote Sensing which was further used to generate a thematic map
using GIS. Secondary data on Rainfall and Temperature changes were analysed using Excel.
Analysis depicted that decreasing vegetation coverage and the increasing temperature ishaving a harming negative impact on the changing monsoon. Such will also help to depict thesocio-economic condition of the region.
Key words: Sundarban Delta, Rainfall Pattern, Temperature Change, Vegetation Coverage.
Introduction
The awe-inspiring adobe of nature “Sundarban” is covering an area of 25,500 sq. km spanning
across both India and Bangladesh. 9,630 sq. km out of this is designated as Indian Sundarban
Delta (ISD). Situated at the confluence of Bay of Bengal it is a part of the largest GangaBrahmaputra Delta. Delineated between 21˚32̍ - 22˚40̍N and 88˚05̍ - 89˚00̍E Indian Sundarban
comprises with the most diversified mangrove cover along with the pride “Royal Bengal Tiger”.
Sundarban has been designated as “World Heritage Site” by “UNESCO” in the year 1997. Thishuge intertidal area consists of islands that are about 102 in number with 42 lakh inhabitants(Das 2011). Hence, it maintains harmony between nature and human life to summarize aproper ecological balance. Its mangrove trees to water resources all provide an occupational
option for the inhabitants (Guha et al 2017). Apart from all these the region is on the verge ofclimatic disparity. The Climate of this region is always dynamic. But with the due course of time
as global warming jailed nature, the climate of the region started behaving in a most unhealthy
way. Moreover, the mangrove or the Sundari plants, for which the region is named, are also
loosing as years are passing. Hence, both these major factors i.e. vegetation coverage andincreasing temperature character is impacting the climate of the region. The major impact is on
the monsoon pattern as noticed by the present work. Monsoon, as suggested is between JuneSeptember (Mondal 2004). It has also been reported that August is the major monsoon rainfall
contributing month (Guhathakurata, Rajevvan 2006). Researchers also claimed that 85 percent
of monsoon rain occurs during advancing monsoon tenure (Gupta n.d). Changing in monsoon
patterns is thus a global concern. Moreover, in ISD its disparity is impacting the ecological toeconomic balance. To find out the cause – the present work mainly relied on the temperatureand vegetation coverage impact on monsoon pattern. Present research work is giving an
insight into the blooming threat in terms of changing monsoon patterns.
Methodology
The Present research study is being carried out in the Indian Sundarban Delta (ISD) as shownin Figure 1. Source: A (West Bengal – Simple English Wikipedia, the free encyclopaedia.), B(West Bengal State. Onefevenine.com), C – Present Research work concluded from Arc GIS
Software. The Importance of the study is directly dedicated to the inhabitants of the region andthe entire city of Kolkata. Working for the same is being busted under the following phases:
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A. Vegetation coverage Analysis is being interpreted by using Cloud-free images of Landsat 45 TM (Thematic Mapper) of years 2005, 2007, 2008, 2009, 2011 and 2012
B. Temperature Change Analysis.
C. Monsoon Pattern change identification.
D. Impact of Vegetation Coverage and Changing Temperature on Monsoon Pattern.
Figure 01: Study Area: Indian Sundarban Delta (ISD)Vegetation Coverage Analysis Using Satellite Technology
For the present analysis, LANDSAT 4-5 TM cloud-free images of Path - 138, Rows - 44 and 45for 2005, 2007, 2008, 2009, 2011 and 2012 have been studied. The said images have beenachieved from EARTH EXPLORER -LANDSAT USGS (USGS, n.d.). Coverage Count has been
determined by NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI) procedure. Vegetation
percentage is being at present times determined by vegetation indices like NDVI, by utilizing e
spectral reflectance of various vegetation covers via satellite data (Guha et al., 2019). The
process of acquiring vegetation information over a vast area is also cost-effective (Das andSingh 2013). Moreover, researchers have acclaimed NDVI to be the most widely usedvegetation cover identification (Manna et.al 2012). Before such analysis the images arechannelled through "pre-processing" steps via ERDAS IMAGINE software: Firstly, “Layer Stacking ’’ coupled all the layers of both the rows of 44 and 45 respectively.
 Such is followed by the “Mosaiking” of layers-tacked images of rows 44 and 45 respectively.
 Area of Interest or AOI has been then "subsisted” from the whole mosaicked image.
 Subsisting, finally lead to the formation of the Indian Sundarban Delta.
Analysis of Temperature Change
Temperature change analysis is being done by calculating the annual average temperature of
2005-2012 with the acquired secondary data from Government of West Bengal’s Department ofAgriculture (Directorate of Agriculture 2017) in Excel Statistics.
Monsoon Pattern Change Analysis
For monsoon, the pattern changes the present study conducted – identification of trend of thenumber of rainy days as well as of average rainfall of monsoon times from 2005-2012.
Research already suggested that the pattern of the monsoon of Sundarban is changing(Pitchaikani et.al 2015). Secondary data for rainfall has been taken from Government of West
Bengal’s Department of Agriculture (Directorate of Agriculture. 2017).
Impact of Vegetation Coverage and Temperature Change on Monsoon Pattern Analysis
The Impact of both Vegetation and temperature change has been glorified via a scatter graphwith further incorporation of the Trend statistics analysis.
RESULTS AND DISCUSSIONS
From the NDVI, the vegetation coverage area in Sq. Km has been identified. In Figures. 2, 3and 4, the Thematic Maps are showing the NDVI classification respectively.
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Figure 03: NDVI Classified Images of 2008 and 2009

Figure 02: NDVI Classified Images of 2005 and 2007

Figure 04: NDVI Classified Images of 2010 and 2011

Graphically, a linearly decreasing trend of vegetation coverage with time is represented inFigure 5. This, in turn, is initiating to indicate that disparity in ecological balance is blooming analarming threat. Similarly, increasing average Temperature via scattering graph (Figure 6) andthe changing monsoon patterns: Rainy days (Figure 7) and Monsoon Average count (Figure 8)
in total is indicating to the onset of the radical climatic changes of ISD. Amidst such alarming
environmental conditions, added caution ringed when the successive statistical and graphicalanalysis indicated that decreasing vegetation decreases the monsoon rainfall (Figure 9) as wellas the rainy days (Figure 10). Researchers also said that various land processes including
vegetation at different temporal and spatial scale influence the climatic system (Dutta et.al2009). Alongside this, increasing temperature threat poised that temperature negatively(decreases) impacts both the Rainfall count (Figure 11) and Rainy day count (Figure 12).

Average Temperature In
Degree Celsius

Vegetation Coverage with Time
VEGETATION COVERAGE(SQ.KM)

3500
VEGETATION
COVERAGE (SQ.KM)

3000
2500
2000
1500

Linear(VEGETATIONCOVERAGE (SQ.KM))

1000
500

02000

2005 2010
YEAR

2015

Figure 05: Decreasing Vegetation Trend withtime.

Average Temperature WithTime
27.2
27
26.8

AnnualAverage
Temperatu
re

26.6
26.4
26.2
262000 2005 2010 2015
YEAR

Linear(Annual
Average
Temperatu
re)Figure 06: Increasing Temperature
Trend with time.

40Figure 07: Monsoon Rainy Days radicalchanging pattern with decreasing mode

Figure 08: Monsoon Rainy Count also facing adecreasing end.

Monsoon Rainy Days

Impact Of Vegetation Coverage
On Monsoon Rainy Days
100

Monso
on
RainyDays

80

60
40

2000

2000

4000

Linear(MonsoonRainyDays)

Vegetation Coverage in Sq.Km

Average Monsoon Rainfall

Figure 9: Vegetation Area Impact on Monsoon
Average Count.
Impact of Average
Temperature on Average
Monsoon Rainfall
201510502626.5
2727.5
Average Temperature

Figure 10: Vegetation Area Impact onMonsoon Rainy Days.

Average
MonsoonRainfall
Linear (Average
MonsoonRainfall)

Figure 11: Average Temperature Impact on
Monsoon Rainfall Count.

Figure 12: Average Temperature Impact on
Monsoon Rainy days.

Conclusion
Present research ranged a long alarm for the India Sundarban Delta with the prefix to the entire
state of West Bengal, as, the state looks forward to protection under natural calamities to ISD.
Outcomes oozed that in this era of global warming ISD is also on the same track of threat withincreasing average temperature along time. We need to mention here that the daily surface
temperature of India has increased by a maximum of 1-1.5 °C (Halder et.al 2016). Indian
Sundarban Delta is meant for its biodiversity and ecological balance which nurtures a healthy
count for the entire state. But with the gradual fall of Vegetation such balance is being underquestion. Since Remote Sensing most prominently determines the coastal vegetation cover(Nayak and Bahuguna 2001), hence, here also the NDVI process has been undertaken. Anadded concern is the conditioning of Monsoon pattern with pace in this region. Again, Indiansummer monsoon i.e., from June to September varies largely (Rasul and Chaudhry n.d).
Research penned here that decreasing vegetation and increasing temperatures are the major
causes behind the rainfall count and rainy day count diminishing. If in this way the rainfall
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decreases then the inflow of fresh water will also be decreased. Hence, an abrupt increase ofsalinity will cause the extinction of many mangrove species (which is the major and key
vegetation of ISD). Extinction or death or natural uprooting of mangrove species will make theISD more naked to natural hazards-will hamper the food cycle of the entire eastern zone fish
community - will directly impact the economy of dependent inhabitants and majorly, will in the
total impact the climatic as well as an ecological condition leading to more fierce environmental
scenario . In support of this, 2010 WWF (Danda 2010) report can be referenced where it ismentioned that the changing monsoon pattern is leading to social imbalance. Hence, animmediate sustainable proper management plan is a much-needed factor for saving the mostfragile ecosystem of the Indian Sundarban Delta.
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