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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
Chapter- IV
Estimation of Forest Cover and Change Detection Analysis 4.1 Introduction
Estimation of vegetation cover is the first step towards the conservation and
sustainable management of forests resources. For the sustainability, necessity of forest
resource data which is accurate and continuously updated is the prime requirement.
Change detection analysis plays a vital role in management process. Change detection
essentially comprises the quantification of temporal phenomena from multi date
imagery that are most commonly acquired by satellite based multispectral sensors.
The present chapter deals with methods applied for the vegetation studies and change
detection in overall LU/LC pattern in the study area.
4.1.1 Methods to study vegetation
Vegetation inventory and monitoring are undertaken at a wide range of scales
depending upon the objectives. There are several methods and techniques designed
for comprehensive studies of community pattern and vegetation dynamics. These
methods of vegetation studies can be grouped in two categories.
4.1.1.1 Conventional methods
There were many traditional methods of vegetation survey and studies in use;
important among these is a quadrate method. This conventional method of vegetation
studies involves vegetation sampling by establishing various sampling units like Area
(quadrates method), Line (transact method) and Point (Point method). The method
can be applied according to the purpose of study. Among these three methods,
quadrate method is used mostly. The location and size of the quadrates depends on the
sampling strategy employed by the researcher. Approaches to sampling distribution
fall into the random, stratified or systematic sampling. Within each quadrate the
species composition can be determined by the number of individuals, presence or
absence or percent cover of each species in each quadrate. Biomass and standing crop
are measured by harvesting, drying and weighing the organic matter within each
quadrate.
4.1.1.2 Remote sensing techniques
One of the primary applications of remote sensing technology is to identify the
patterns of spatial and temporal distribution of vegetation on the ground. Remote
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
sensing has several advantages over traditional methods of vegetation mapping and
has been proved to be a very powerful tool in deriving information on natural
resources and environment. Remote sensing is the science and art of obtaining
information about an object, area or phenomena through the analysis of data acquired
by a device that is not in contact with the object, area or phenomena under
investigation (Lillsand and Keifer, 1999). For this purpose, different wavelength
regions of the electromagnetic spectrum are used. Electromagnetic radiation (EMR) is
comprised of large spectrum of wavelength right from short wavelength cosmic rays
to long radio waves. In remote sensing, the most useful regions are the visible (0.4-
0.7 µ), reflective infrared (0.7-3.0 µ) thermal infrared (3.0 to 5.0 and 8.0 to 14.0 µ)
and the microwaves (1mm to 1m). Although the incoming solar radiation reaching to
the earth surface is modified by the atmospheric gaseous, aerosols and water vapor,
using atmospheric corrections to imagery good quality information can be obtained.
All type of remote sensing systems, capture radiation in different wavelengths
reflected or emitted by the earth surface features and record it either directly on the
film as in case of aerial photography or on a digital medium like tape and later, it is
used for generating image. As no two objects in nature are theoretically ditto, their
signatures are most likely to be unique.
The reflectance from vegetation is controlled by leaf pigments, cell structure
and leaf water content. The radiation absorbed in red region is primarily used for
photosynthesis. In healthy vegetation, both absorption and reflectance is more
pronounced, while diseased and senescent vegetation show lesser absorption and as
well as reflection. These spectral properties of vegetation are heavily exploited to
detect their type, density and condition through image interpretation.
The remote sensing data from aerial and satellite platform plays a significant
role in forests resource survey, monitoring forest cover, evaluating ecosystem,
studying wildlife, assessing plant disease etc. the mapping for the forest type or
vegetation is essential for forest resource survey. A complex mixture of many tree
species, in contrast to a single crop field, very often occupies a forest land. Hence the
identification of tree species is rather difficult and needs a prior knowledge of the
area. A study of the changes in appearance of trees in different seasons of the year
utilizing the multi date data helps in discriminating the species that are
indistinguishable on a single data image. It is, however difficult to interpret the
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
species composition of an understory since it is beneath the forests canopy. It is
possible for example, to map a clear cut or deteriorating forest area, monitor broad
changes in forest cover, and detect a forest fire with the help of high resolution
satellite data at periodic intervals. A forest fire can be very easily detected in the
remotely sensed data since the burning of the forest canopy eliminates the infrared
reflection from leaves, allowing the radiation to reach the ground where it is highly
absorbed by the charred ground flora and thus exhibits a dark or black tone in images.
However, the mapping of forest fire damage below the smoke of fire is difficult with
the optical sensor data. In such cases the thermal data may be utilized to map the hot
pixels.
Satellite remote sensing, because of its capacity to provide a repetitive
coverage of both coarse and fine resolutions, is a very powerful tool for monitoring
forest cover and change detection. The remotely sensed data collected sequentially
provide information on any positive or negative changes in the vegetation cover,
which is reflected in the image by a corresponding change in the spectral signature. A
superimposition of two period maps delineates the areas where the changes have
taken place. It is also possible to monitor the amount of vegetation loss and
encroachment on forest lands, utilizing high resolution satellite images.
Accuracy and high resolution ability of sensors and visual and digital image
processing algorithms are now very useful to extract important vegetation biophysical
information from remotely sensed data.The use of satellite data with three dimension
analysis, particularly of the aerial photographs, can help in monitoring the ecological
status of the forests, which is essential information for rational management. The
monitoring of an actual forest at regular intervals can establish the depletion rates and
also trends in critical areas.
4.2 Image classification
Image Classification is the most widely used technique in remote sensing
applications for extraction of target thematic information. For the present research
work, land use and land cover information is the prime prerequisite to understand the
spatio-temporal scenario of land use land cover pattern in general and area under
forest cover in particular. Image classification is a process of mapping to generalize
the image pixels into meaningful groups each resembling different land category
(Jensen, 1995). The process requires an optimum and specifically designed
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
classification algorithm for precise application purpose because it largely varies
depending upon the type and objective of the work. Most common and typical method
for satellite image classification is based on pixel. In this method, classifier considers
different pixel values and group them into classes solely based on their spectral
properties. This practice is based on conventional statistical techniques such as
supervised and unsupervised classification where the classes are supervised by analyst
and are not supervised (i.e. fully automatic based on spectral values) respectively.
4.2.1 Selection of land use classes for image classification
The classification system amenable for use with remote sensor data varies
with the objectives of the classification and type of the satellite data that is being used.
There are many methods of land use classification like U.S. Geological Survey
scheme, NRSC etc. For the present study, “National Land use Land cover mapping
using Multi temporal Satellite data” classification scheme given by NRSC, India has
been followed. (Table 4.1)
4.2.2 Classification output
The output of the classified image was obtained as thematic maps for each
selected year. Classified satellite image, with classes defined earlier were displayed
using various traditional colors. All these classified images were later used for the
visual interpretation for understanding the changes in land use and land cover pattern
in the study area. The output images obtained through the classification were further
subjected to change detection analysis also. Before performing the further studies it
was essential to test and check the accuracy of the classification.
4.2.3 Accuracy assessment
Classification cannot be completed until its accuracy has been measured
(Lillesand T. M. 1987). Accuracy means the level of agreement between labels
assigned by the classifier and the class allocations on the ground collected by the user
as test data. After the unsupervised classification, it was necessary to assess the
accuracy of the classified maps. It is very important as it gives the idea, that at which
levels of accuracy of the thematic maps are prepared. Generally for the accuracy
assessment map based on different source of information and analyzed map obtained
through remotely sensed data is compared. Producer and user accuracy is collected for
each class. Overall accuracy for the classified IRS 1C LISS image of the year was
85% collected and for the images of IRS P6 LISS, 2008 and IRS P2 LISS, 2012 it was
No
Land Use Land Cover
Classification
Description
Level I Level II
1 Water Body
Reservoir and riversAreas with surface water, ponds, lakes reservoir or
flowing streams or rivers
Dry river bedShows maximum water level in the reservoir out of
its capacity
2Agricultural
Land
Cultivated landAreas with standing crops in the field
Agricultural fallow
Lands which are taken up for cultivation but now are
temporarily allowed to rest, un cropped for less than
year
3 Forests
Moderately dense
Forest
Areas comprising thick and dense canopy of tall
trees, predominantly remain green throughout the
year, density, usually between 40% to 70%
Open forest
Combination of evergreen and deciduous forests,
found along the margins of Evergreen forests,
covering canopy density between 10% to 40%
Scrub / Degraded
Forest
Degraded forests lands, where crown density is less
than 10% of canopy cover
4 Wastelands
Barren Land Areas un cropped or un utilized for a longer period
Rocky waste
Lands of rocky waste of varying lithology often
barren and devoid of soil erosion and vegetation
cover
5 Built up landBuilt up area- rural
(Settlements)
Lands used for human habitation for living, sized
comparatively less than urban settlements.
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Table 4.1 Land use and land cover classes under consideration and their description
NRSC classification scheme
Chapter IV: Estimation of Forest Cover and Change Detection Analysis
KHADAKWASALA IRRIGATION PROJECT DIVISION
unclassifed
Reservoir and Rivers
Dry river bed
Moderately dence forest
Open forest
Agricultural fallow
Cultivated land
Scrub/ degraded forest
Builtup area
Barren land
Rocky waste land
Land Use Land Cover - 1997
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Fig 4.1
KHADAKWASALA IRRIGATION PROJECT DIVISION
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unclassifed
Reservoir and Rivers
Dry river bed
Moderately dence forest
Open forest
Agricultural fallow
Cultivated land
Scrub/ degraded forest
Builtup area
Barren land
Rocky waste land
Land Use Land Cover - 2008
69
Fig 4.2
KHADAKWASALA IRRIGATION PROJECT DIVISION
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Reservoir and Rivers
Dry river bed
Moderately dence forest
Open forest
Agricultural fallow
Cultivated land
Scrub/ degraded forest
Builtup area
Barren land
Rocky waste land
Land Use Land Cover - 2012
70
Fig 4.3
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Land use class Year
Level I Level II
1997 2008 2012
Area
(km2) Area (%)
Area
(km2) Area (%)
Area
(km2) Area (%)
1
Water bodyReservoir and rivers 33.43 7.39 33.23 7.35 25.7 5.68
Dry river bed 4.66 1.03 9.1 2.01 14.53 3.21
2
Agricultural LandCultivated land 4.84 1.07 4.9 1.08 6.73 1.49
Agricultural fallow 51 11.28 50.13 11.09 42.75 9.45
3
Forests
Moderately Dense forest 168.56 37.27 108.45 23.98 53.79 11.89
Open Forests 118.24 26.15 130.92 28.95 134.61 29.77
Scrub/ Degraded forest 21.06 4.66 50.23 11.11 57.08 12.62
4
WastelandsBarren Land 11.6 2.57 16.44 3.64 27.68 6.12
Rocky waste lands 21.66 4.79 24.46 5.41 48.06 10.63
5 Built up land Built up area 17.16 3.79 24.36 5.39 41.29 9.13
TOTAL 452.22 100 452.22 100 452.22 100
Table. 4.2. LU/LC statistics for different time period of the study area
KHADAKWASALA IRRIGATION PROJECT DIVISION
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
80%. However kappa statistics was collected 0.7770, 0.7394 and 0.7695 respectively.
In the present study, major constraint was non-availability of land use and land cover
map of which can be taken as a reference point. GCP’s and Google Earth images were
used as a reference for the classification.
4.3 Spatio-temporal variation in LU/LC changes in the study area
The term, Land use and land cover are inseparable. Land use is the term that is
used to describe human uses of land, or immediate actions modifying or converting
land cover (Sherbinin A.D. 2002). On the other hand, land cover refers to the natural
vegetative cover types that characterize a particular area. Land cover is the layer of
soil and biomass, including natural vegetation, crops and manmade infrastructures
that cover the land surface. Land use is the purpose for which human make a use or
exploits the land cover (Fresco, 1994, cited in Verburg et al., 2000). Changes in Land-
use proximately cause change in land-cover pattern. Land use is obliviously
constrained by environmental factors such as soil characteristics, climate, topography
and vegetation. But it also reflects the land as key and finite resources for most human
activities comprising agriculture, industry, forestry, energy, production, settlement,
water catchments and storage (Bhat, Sulemeiman, Abdul, 2009). The knowledge of
land use and land cover is of immense important and useful to understand the natural
resources, their proper utilization, conservation and management. The driving forces
to this activity could be economic, technological, demographic, scenic and or other.
Hence, land use and land cover dynamics is a result of complex interactions between
several biophysical and socio-economic conditions which may occur at various
temporal and spatial scales (Reid R.S. et al., 2000).
Land use and land cover pattern are mostly affected by human intervention
and natural phenomena such as agricultural demand and trade, population growth,
land consumption patterns , urbanization and economic development, science and
technology, and other factors (Research on Land use change & Agriculture,
International Institute for Applied Systems Analysis, 2007). Hence, information about
land use land cover is essential for any kind of natural resource management and
action planning. Timely and precise information of land use and land cover change
detection has a great importance in understanding relationships and interactions
between human and natural phenomena for better management of decision making
(Lu D. et al., 2004) Unsupervised classification method is applied for the IRS 1C
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
LISS III (1997), IRS P6 LISS III (2008) and IRS P2 LISS III (2012) images in
ERDAS IMAGINE 9.3. All these satellite images are of the month of February and
March. After systematic and accurate classification attribute data is generated
regarding the land cover classes under the consideration. This data has been
summarized in Table 4.2 & 4.3.
Fig 4.1, shows the land use classes for the February 1997 derived from the
classified image of the IRS 1C, LISS III sensor. Ten major land use classes were
obtained from the satellite data. During the classification of images major thrust is
given on vegetation dynamics. It can be clearly observed that, almost throughout the
study area, significant and noticeable patches of the moderately dense vegetation are
located along the interfluve area whereas open forest (semi evergreen) are spread in
entire study area. On the sloping lands rocky waste lands are more than barren lands.
Rocky barren lands are dominated in the central part of the study area and observed
mainly in Khadakwasala catchment. Most of the settlements are observed along the
banks of the reservoir and agricultural lands are well distributed around the
settlements and along with water bodies. Scrublands and degraded lands are almost
negligible.
Fig 4.2 demonstrate land use classes for the year February 2008 obtained from
IRS P6 LISS III image of 2008. It can be clearly seen the area under settlement within
a span of eleven years has increased significantly. This has been observed particularly
in Khadakwasala lake catchment. Western part of the catchment remained same
during the period in terms of built up land. During this period area under the
moderately dense vegetation has been decreased, especially towards the eastern parts
of the study area. Moderately dense vegetation is observed only in western part of the
study area, as this is the region away from the settlements. In Panshet catchment along
the reservoir and towards eastern part of Khadakwasala scrub and degraded forests are
considerably increased.
Fig 4.3 shows, land use classes for the year March 2012 obtained from IRS P2
LISS III image of 2012. The figures of various land cover classes from the images
shows dramatic change over in the period taken into consideration. This change is
observed more in eastern part of the study area i.e. Khadakwasala lake catchment
where most of the vegetative areas are now converted into barren and built up land,
mainly because this part of the study area is very close to the Pune city and Sinhagad
No LULC type
LULC LULC Change between Average rate
1997 2012 1997 & 2012 of change
Area
(km2) Area (%)
Area
(km2) Area (%)
Area
(km2) Area (%)
(km2)/ (%)/
Yr Yr
1 Reservoir and rivers 33.43 7.39 25.7 5.68 -7.73 -23.12 -0.52 -1.54
2 Dry river bed 4.66 1.03 14.53 3.21 9.87 211.8 0.66 14.12
3 Cultivated land 4.84 1.07 6.73 1.49 1.89 39.05 0.13 2.6
4 Agricultural fallow 51 11.28 42.75 9.45 -8.25 -16.18 -0.55 -1.08
5 Moderately Dense forest 168.56 37.27 53.79 11.89 -114.77 -68.09 -7.65 -4.54
6 Open Forests 118.24 26.15 134.61 29.77 16.37 13.84 1.09 0.92
7 Scrub/ Degraded forest 21.06 4.66 57.08 12.62 36.02 171.04 2.4 11.4
8 Barren Land 11.6 2.57 27.68 6.12 16.08 138.62 1.07 9.24
9 Rocky waste lands 21.66 4.79 48.06 10.63 26.4 121.88 1.76 8.13
10 Built up area 17.16 3.79 41.29 9.13 24.13 140.62 1.61 9.37
TOTAL 452.22 100 452.22 100
Table. 4.3. Average rate of change in LU/LC for the year 1997 and 2012 in the study area
KHADAKWASALA IRRIGATION PROJECT DIVISION
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
fort, a well known tourist center. Moderately dense vegetation is observed only
towards the western part along ridge line at considerable elevation. Degradation of
forests cover has increased and it can be observed in entire eastern part of the study
area. Increased cultivation patches are observed along the margins of reservoir only.
4.4 Change detection analysis of the LU/LC in the study area
Mapping of land use land cover (LULC) and change detection analysis using
remotes sensing and GIS technology is an area of interest that has been attracting
increasing attention of researchers and planners. Land use land cover change detection
is very essential for better understanding of landscape dynamics during a known
period of time for sustainable management. The process of change detection is most
frequently associated with environmental monitoring, natural resource management
and measuring urban development. Understanding landscape patterns, changes and
interactions between human activities and natural phenomena are essential for proper
resource management and decision making (Prakasam C. 2010).
Land use land cover change has been recognized as an important driver of
environmental change on spatial as well as on temporal scales (Tansey et al., 2006).
Remote sensing technology for capturing the spatial data on various resolutions, GIS
for undertaking integrated analysis and presentation of attribute data are found to be
much more effective to know the change detection of land use and land cover
(Lillesand T.M. et al., 1987).
It can be clearly observed that, the land use land cover pattern of the study
area has been changed dramatically during the last fifteen years. Therefore, the data
interpretation and data analysis is based on the comparison of LU/LC for three
different time periods viz 1997, 2008, and 2012. Area under major land use land
cover category has been categorized into five major classes (Level I) and ten
subclasses (Level II). Following observations for this time period of fifteen years has
been noted as following. (Table 4.3 & 4.4)
4.4.1 Change in water bodies
The rivers and three reservoirs namely Panshet, Khadakwasala and Warasgaon
are considered in this category. The changing rate of water bodies is showing
deceasing trend as it totally depends on and the annual rainfall in the study area and
requirements of beneficiary regions. All these three catchments provide water for
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
drinking and agriculture purpose to adjacent cities like a Pune as well as Baramati and
Indapur tehsils. Since the last decade the demand of water for the domestic, industrial
and agricultural purpose has been increased. Hence up to the month of April the water
level significantly goes down. During the year 2011, due to the drought conditions all
these three catchments are showing only 5.68 % water. It can be observed from the
area under the dry river bed which is 3.21% in 2012.
4.4.2 Change in agricultural lands
The observations gained through the image interpretation reveals that area
under the cultivated land is showing very negligible change as the entire study area is
characterized by hilly terrain and undulating topography. Very few places are having
flat surfaces for cultivation and these areas are mostly confined to the banks of
reservoirs. During the monsoon, paddy cultivation is performed on hill slopes. It
shows that in the year 1997 area under cultivation was 1.07 % which is increased up
to 1.49% in 2012. During the field visit, it was also observed that Nachani is grown
in the western hilly tract of the study area, towards eastern part, lentils like pawata
(Dolichos lablab), masoor (Lens esclenta), gram (Cicer arietinum) are grown. Along
the banks of reservoir particularly Khadakwasala, creepers of cucumber, red pumpkin
along with vegetables like math, rajgira, chilli, and sweet potato are grown. The area
under the cultivation has shown an increase of 39.05% within this span.
Agricultural fallow lands are those lands which are available for cultivation
but not used for one or the other reason. The agriculture activities in such land are
totally dependent on monsoon. Most of the surface area under agricultural fallow is
utilized in rainy season only. This area under fallow was 11.28 % in the year 1997 and
it has been decreased slightly to 9.45% in 2012. Average annual decrease of fallow
land is observed to be 1.08% per year.
4.4.3 Change in forests
In order to compute the growth and decrease in the forest cover, following
formula is common use by forest survey of India. This formula has been used in the
computation of forest growth from the base year 1997.
Percentage Growth/Loss = B – C
B × 100
Where, B is Base year value, and C is current year value
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
Land cover class under the forest is continuously decreasing year by year and
shows negative change. It was found that area under the moderately dense forests,
which was 37.27% in the year 1997, comes down to 11.89% in the year 2012. It has
been decreased by 68.09% within the fifteen years of span. Although open forests
show slight positive growth by 13.84% from 1997 to 2012, most of the previously
moderately dense forests are now thinning and few plantations around the settlements
are observed. Forests patches are mostly found at high altitudinal zone and in villages
towards western part of the study area. Scrub or degraded forests however shows
continuous and tremendous increase by 171.04% from 1997 to 2012. The negative
change in the forest is only because of increasing human population, as well as need
of forest product to satisfy daily livelihoods. The rate of degradation or increase in
scrub forest was found to be 11.40% per year.
4.4.4 Change in wastelands
One of the significant changes in land cover is observed in degradation of
lands i.e. increase in wastelands, which is showing continuous increasing trend. In the
year 1997 area under barren land was 11.6 km2 (2.57%), which increased up to 27.68
km2 (6.12%) in the year 2012. The total 138.62% growth during this period has been
observed. Area under rocky waste has also been increased by 121.88 % from 4.79%
in 1997 to 10.63% in 2012. Both barren land and rocky waste shows significant
increase after the year 2008 from 3.64% to 6.12% and 5.41% in 2008 to 10.63% in
2012 respectively. During the extensive field survey it was observed that the intensive
encroachment of anthropogenic activities are increasing ecological stress and leading
to soil erosion on hill slopes and land degradation. In period of heavy monsoon due
the lack of vegetative cover along the slopes, most of the valuable soils washed out
leaving behind the open bare land surfaces.
4.4.5 Change in built up land
The observation also indicated that built up area has increased from 3.79% in
1997 to 9.13% in 2012 and this growth is about 140.62%. One noticeable change
behind this is increase in human population in villages under the study area and
expansion of fringe area around the Pune city. Average rate of increase in built up
area was observed to be 9.37% per year. Since 2008 this rate of increase more
pronounced as the area under built up land has been doubled in four years.
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
4.5 Catchment wise change in the study area
Table 4.4 shows change detection analysis between 1997 to 2012. The upper
Mula sub basin has undergone a sharp change during recent years. Entire study area
has witnessed drastic changes in its land use and land cover pattern since last few
years. The major reasons of these changes are the expansion and urbanization of small
sub urban areas in the eastern part of the watershed. Urbanization is one of the most
widespread anthropogenic causes of the loss of arable land (Lopez, et al., 2001),
habitat destruction (Alphan, 2003), and the decline in natural vegetation cover. One of
the major reasons of urbanization is rapid population growth in the urban area. Due
the over expansion of urban areas in Haveli, Daund and Baramati tahsils the
requirement of water for domestic as well as for agricultural and industrial purpose is
increased, hence to satisfy this need two new small sized watershed namely
Warasgaon and Temghar are constructed on Ambi and Mutha river respectively. Prior
to this, Panshet on Mose River and Khadakwasala on Mutha River were the only
sources of water. The primary aim of these four reservoirs is to provide the water for
agriculture, drinking and industrial purpose.
As urban population increases, the demand of land for various urban activities
also increases. In India, the process of urbanization gained momentum with the start
of industrial revolution and globalization way back in 1970s. Forests, grasslands,
wetlands and croplands were encroached upon under the influence of expanding
cities, yet never as fast as in the last decade. Various studies have revealed that, main
basis of urbanization is the socio-economic transformations and in particular the
growth of secondary and tertiary occupation in urban areas (Fazal, 2001).
Villages in study area belong to three rapidly changing tehsils of Pune district
and those are Mulshi, Velhe and most importantly Haveli. Overall growth has been
putting pressure on the existing land use pattern of study area. As a result of it
vegetation cover, agricultural land and fallow land has been now transforming into the
built up land. Haveli tehsil, particularly in Pune city Information Technology (IT)
sector has expanded the margins of the area. Many small IT hubs are newly being
opened up in the vicinity of Pune city. On the other hand, among all the tehsils of
Pune, Mulshi is rapidly developing in tourism activity. Population trend in last few
years has been responsible in changing the pattern of land use and land cover in the
entire catchment.
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Chapter IV : Estimation of Forest Cover and Change Detection Analysis
4.5.1 Change in LU/LC pattern of Khadakwasala reservoir catchment
Khadakwasala irrigation project include three main catchments namely
Panshet, Warasgaon and Khadakwasala itself. For all these three catchments land use
land cover analysis have been exercised using IRS 1C LISS III and IRS P2 LISS III
satellite data for the year 1997 and 2012 respectively. Entire study area has
undergone sharp changes since last decade. Table shows the data of land use land
cover of three watersheds. The analysis between the year 1997 and 2012 has provided
important insight in to the land cover dynamic in all three catchments.
It can be observed that, in Khadakwasala catchment, barren land has been
increased tremendously by 316.48% per year within last fifteen years. These bare
surfaces may now be used in future for other land cover classes. Change in built up
by 4.93% per year can be observed. A famous Sinhagad Fort, backwater of
Khadakwasala reservoir, Nilkantheshwar temple etc are the major attraction points
for the weekend hence the tourism activities has been increased considerably.
Out of these three catchments, Khadakwasala lake catchment has large land
surface area under the reserved forests. This area has still extremely rich flora and
fauna including some rare endangered species (Ingalhalikar S., 2005). It is known as a
hot spot habitat for biodiversity. Positive aspect in this catchment is only that the
barren hill slopes now have good plantation and trees are being planted by the forests
department mainly around the Sinhagad Fort. The forest at lower level is dominated
by plantations made by the forests department, which includes prominent exotic
species like Teak, Australian Acacia and Eucalyptus. Native flora of plant species has
been disappeared and exotic species are introduced. At the foot hills where the soils
are deep, some survival of planted species can be noticed. Large scale deforestation in
the foothills around the Sinhagad fort has been observed. There is about 96.05% of
reduction in moderately dense forest where as 270.62 % increase in scrub or degraded
forest. Most of the areas showing increase in open forests were previously densely
forested and now due to the encroachment the area under dense forests are decreasing.
The massive change in the forests cover is due to the human induced activities and
unsound forests management practices. Major consequences in the forests of
Khadakwasala catchment, apart from the destruction is thinning process of forests, i.e.
the forests are altered which makes change in forests type form dense to open or
scrub/ degraded. Native tracts of forests are separated into patches due to the
increasing anthropogenic activities.
Khadakwasala
LULC 1997 LULC 2012
Change between Average rate
Catchment 1997 & 2012 of change
No Land cover class Area (km2) Area (%) Area (km2) Area (%) Area (km2) Area (%) km2/yr %/yr
1 Reservoir and rivers 7.7 5.68 9.55 7.05 1.86 24.12 0.12 1.61
2 Dry river bed 0.17 0.12 0.93 0.69 0.77 459.47 0.05 30.63
3 Cultivated land 2.43 1.8 4.3 3.18 1.87 76.92 0.12 5.13
4 Agricultural fallow 26.13 19.29 25.86 19.09 -0.28 -1.06 -0.02 -0.07
5 Moderately Dense forest 49.38 36.45 1.95 1.44 -47.43 -96.05 -3.16 -6.4
6 Open Forests 21.04 15.53 30.11 22.23 9.07 43.11 0.6 2.87
7 Scrub/ Degraded forest 4.95 3.65 18.35 13.54 13.4 270.62 0.89 18.04
8 Barren Land 0.21 0.15 10.11 7.47 9.9 4747.21 0.66 316.48
9 Rocky waste lands 14.41 10.64 18.56 13.7 4.15 28.79 0.28 1.92
10 Built up area 9.04 6.68 15.73 11.62 6.69 74 0.45 4.93
TOTAL 135.46 100 135.46 100
Panshet
LULC 1997 LULC 2012
Change between Average rate
Catchment 1997 & 2012 of change
No Land cover class Area (km2) Area (%) Area (km2) Area (%) Area (km2) Area (%) km2/yr %/yr
1 Reservoir and rivers 10.75 9 9.32 7.81 -1.43 -13.28 -0.1 -0.89
2 Dry river bed 2.06 1.73 2.85 2.39 0.78 38 0.05 2.53
3 Cultivated land 0.06 0.05 0.4 0.33 0.34 620.91 0.02 41.39
4 Agricultural fallow 8.41 7.04 1.38 1.16 -7.03 -83.59 -0.47 -5.57
5 Moderately Dense forest 51.8 43.38 22.51 18.86 -29.28 -56.54 -1.95 -3.77
6 Open Forests 35.92 30.08 37.01 31 1.09 3.03 0.07 0.2
7 Scrub/ Degraded forest 5.8 4.86 16.82 14.09 11.02 189.97 0.73 12.66
8 Barren Land 1.17 0.98 7.55 6.33 6.38 543.11 0.43 36.21
9 Rocky waste lands 1.79 1.5 12.78 10.71 10.99 614.23 0.73 40.95
10 Built up area 1.63 1.37 8.76 7.34 7.13 436.44 0.48 29.1
TOTAL 119.39 100 119.39 100
Warasgaon
LULC 1997 LULC 2012
Change between Average rate
Catchment 1997 & 2012 of change
No Land cover class Area (km2) Area (%) Area (km2) Area (%) Area (km2) Area (%) km2/yr %/yr
1 Reservoir and rivers 15.14 11.35 6.93 5.19 8.21 -54.25 0.55 -3.62
2 Dry river bed 2.58 1.94 10.1 7.57 -7.51 290.73 -0.5 19.38
3 Cultivated land 0.23 0.17 0.42 0.32 -0.19 83.6 -0.01 5.57
4 Agricultural fallow 4.86 3.64 5.15 3.86 -0.29 6.01 -0.02 0.4
5 Moderately Dense forest 45.79 34.31 31.33 23.48 14.46 -31.57 0.96 -2.1
6 Open Forests 46.97 35.19 42.27 31.67 4.7 -10.01 0.31 -0.67
7 Scrub/ Degraded forest 8.53 6.39 11.99 8.99 -3.46 40.6 -0.23 2.71
8 Barren Land 3.94 2.95 3.59 2.69 0.35 -8.92 0.02 -0.59
9 Rocky waste lands 2.48 1.86 11.42 8.55 -8.93 359.98 -0.6 24
10 Built up area 2.93 2.19 10.25 7.68 -7.32 250.11 -0.49 16.67
TOTAL 133.46 100 133.46 100
Table 4.4 Catchment wise LU/LC and change detection
KHADAKWASALA IRRIGATION PROJECT DIVISION
Chapter IV: Estimation of Forest Cover and Change Detection Analysis79
81
Chapter IV : Estimation of Forest Cover and Change Detection Analysis
4.5.2 Change in LU/LC pattern of Panshet and Warasgaon reservoir catchment
Panshet and Warasgaon reservoirs are located towards about the 40 km south
west of Pune city in Velhe and Mulshi tehsils of Pune district in the flanks of Western
Ghats. Panshet reservoir is built in 1971 (reconstructed after breaking in 1961) on the
river Ambi, which originates near village Dapsare, while Warasgaon reservoir is built
in (1976) on the river Mose, which originate near village Dhamanohol. The terrain
consists of low lying valley to high dissected ridges forming ridge valley topography.
Panshet and Warasgaon have formed extensive lakes in the valleys, flanked on either
side by hills which rises more than 600 m. the hill slopes are dotted by small villages
with populations ranging from 100 to 400. The catchment area of these reservoirs is
119.39 & 133.46 km2 which include around 45 villages with combined population of
8,974 according to 2011 census.
These catchments lie just next to east of the crest line of the Western Ghats at
the altitude of about 600 m. In some parts the terrain is very much broken with narrow
valleys of less than half a km in extent separated by steep hills rising to altitudes of
around 1200 m. The people are poor and mostly marginal farmers depending heavily
on traditional farming techniques which is called as shifting cultivation by slash and
burn technique of forest according to the seasons. Previously the villagers cultivate
paddy on the flat land in the valley, most of which are now submerged under the
reservoir. Hill slopes particularly in the Panshet are fairly remote from the villages
which are still covered by forests. The land in Warasgaon is purchased by the Lake
City Development Corporation, Pune and they are developing Model Hill Station
known as “Lake Town”. The work of one small city known as “Lavasa” is recently
developed.
Hill slopes had a good tree cover of Mangifera indica (Mango) and Terminilia
chebula (Hirda), for these cash-yielding trees used to be spared by the peasants while
clearing for millets cultivation. The nuts of hirda used extensively for tanning
supported a flourishing industry at Bhor. The upper hill slopes were clothed by rich
natural forests of semi evergreen type, constituted into state owned forests reserves.
These forests were hardly exploited due to the lack of transport facilities (Gadgil &
Vartak, 1976). During the decade of 1950-60 all these forest were cut down. This has
led to condition that most of the land is now entirely barren and heavily eroded; also
82
Chapter IV : Estimation of Forest Cover and Change Detection Analysis
the encroachment by the villagers in remained forests area has increased as the
productivity of their fields is declining. In 1963, government acquired the land of the
farmers for construction of Panshet dam. When the construction of the dams
completed, most of the lands never comes under water or catchment and this land
surface area thus remained unutilized. Most of the land is tilling by the local farmers
with the agreement of state government.
Table 4.4 shows that area under cultivated land in Panshet and Warasgaon is
very low, i.e. 0.4 and 0.42 km2
respectively. Physical constraint is the only factor
which has retarded the agricultural growth in these catchments. However during
monsoon this area under agriculture increases as, paddy cultivation is practiced
mostly in valleys. Change in moderately dense forest land is also noticed in Panshet
and Warasgaon catchment and it shows decrease by 3.77% and 2.1% per year
respectively. Scrub land is also increasing by 12.66% and 2.71% per year in Panshet
and Warasgaon respectively. Growth in barren and rocky waste land in Panshet is
more as compared to Warasgaon and it is 36.21% and 40.95% per year as in
Warasgaon it is 0.59% and 24% per year. Rate of growth in built up area in Panshet is
observed to be 29.1% and in Warasgaon it is to be 16.67% per year. The
encroachment now can be seen in remote and in accessible parts of the study area as
the transportation facility has been substantially improved.
4.6 LU/LC change assessment using Markov chain method
Land Use Land Cover Change (LULCC) is a major driver of a global change.
Since last few decades, the magnitude and spatial reach of human impacts on the
earth’s land surface is unprecedented (Lambin et al, 2001). Change in land cover and
land use has been accelerating as a result of socio-economic and biophysical drivers
(Turner et al. 1995, Lambin et al, 1991). These are closely linked with the issues of
the sustainability of a socioeconomic development since they affect essential parts of
natural capital such as vegetation, biodiversity and water resources (Mather and
Sdasyuk, 1991).
To understand and to infer what and where changes have occurred, and at
what pace such changes will happen a reliable model is require in this context. It will
also provide the information about future trends if the driving forces continue to
function in the same or alternative way.
1997-
2008 1 2 3 4 5 6 7 8 9 10 1997
1 27.94 2.51 0.63 1.02 0.62 0.17 0.20 0.14 0.19 0.03 33.43
2 0.37 1.56 0.12 0.89 0.27 0.05 0.68 0.29 0.29 0.15 4.66
3 4.28 2.69 56.76 51.73 14.56 2.80 18.92 7.04 4.87 4.90 168.56
4 0.05 0.32 31.56 45.64 10.01 0.17 15.25 5.63 5.16 4.46 118.24
5 0.23 0.64 9.06 12.83 10.56 1.38 4.65 4.38 2.56 4.71 51.00
6 0.03 0.04 0.94 1.07 1.44 0.21 0.35 0.58 0.01 0.18 4.84
7 0.06 0.86 4.15 6.67 2.64 0.07 4.00 1.57 0.51 0.54 21.06
8 0.02 0.19 1.97 3.66 4.51 0.03 2.47 2.19 0.49 1.63 17.16
9 0.26 0.30 0.67 2.72 2.07 0.00 1.62 1.33 1.01 1.63 11.60
10 0 0.00 2.59 4.70 3.46 0.00 2.09 1.22 1.35 6.23 21.66
2008 33.23 9.10 108.45 130.92 50.13 4.90 50.23 24.36 16.44 24.46 452.22
2008-
2012 1 2 3 4 5 6 7 8 9 10 2008
1 18.22 5.78 0.49 1.92 0.71 0.34 1.40 0.41 2.87 1.08 33.23
2 1.81 2.65 0.57 1.15 0.27 0.07 0.66 0.61 0.78 0.53 9.10
3 1.29 0.92 20.39 37.35 6.70 1.03 16.20 8.13 5.70 10.75 108.45
4 1.29 2.12 24.73 43.68 10.04 1.62 16.41 11.47 6.50 13.06 130.92
5 1.22 0.62 0.80 12.84 12.00 1.86 6.19 7.92 3.60 3.07 50.13
6 0.45 0.18 0.12 3.05 0.42 0.25 0.08 0.21 0.04 0.11 4.90
7 0.60 1.24 4.99 18.30 3.37 0.39 9.06 4.95 4.06 3.26 50.23
8 0.47 0.53 0.85 5.98 5.15 0.70 2.68 3.64 1.38 2.99 24.36
9 0.26 0.33 0.56 3.18 0.44 0.04 1.16 1.37 1.17 7.93 16.44
10 0.10 0.15 0.29 7.16 3.65 0.42 3.25 2.58 1.59 5.28 24.46
2012 25.70 14.53 53.79 134.61 42.75 6.73 57.08 41.29 27.68 48.06 452.22
Table 4.5a LU/LC Transition of the successive periods (Area km2)
KHADAKWASALA IRRIGATION PROJECT DIVISION
1 Reservoir and rivers
2 Dry river bed
3 Moderately dense forest
4 Open forests
5 Agricultural fallow
6 Cultivated land
7 Scrub/ degraded forest
8 Built up area
9 Barren land
10 Rocky waste lands
INDEX
Source : Author
Ch
ap
ter IV: E
stima
tion
of F
orest C
ov
er an
d C
ha
ng
e Detectio
n A
na
lysis
83
1997
2012 1 2 3 4 5 6 7 8 9 10 1997
1 20.83 6.82 0.48 1.15 0.3 0.15 0.68 0.18 2.81 0.03 33.43
2 1.57 1.72 0.09 0.3 0.01 0 0.06 0.1 0.69 0.13 4.66
3 1.6 2 27.27 55.59 14.43 2.43 25.43 13.81 11.16 14.85 168.56
4 0.18 0.59 22.08 42.28 8.43 0.66 13.97 11.81 4.34 13.88 118.24
5 0.39 1.19 1.26 13.15 9.46 1.63 6.73 6.52 3.64 7.03 51
6 0.59 0.13 0.15 1.09 1.07 0.58 0.58 0.44 0.22 0.01 4.84
7 0.42 1.29 1.63 5.75 2.17 0.43 3.33 2.46 1.33 2.25 21.06
8 0.12 0.49 0.3 4.45 2.98 0.44 1.87 2.98 0.81 2.7 17.16
9 0 0.18 0.32 4.01 1.29 0.17 1.16 1.19 1.2 2.08 11.6
10 0.01 0.13 0.2 6.85 2.61 0.23 3.28 1.79 1.48 5.09 21.66
2012 25.7 14.53 53.79 134.61 42.75 6.73 57.08 41.29 27.68 48.06 452.22
Table 4.5b LULC Transition of the successive periods (Area km2)
KHADAKWASALA IRRIGATION PROJECT DIVISION
1 Reservoir and rivers
2 Dry river bed
3 Moderately Dense forest
4 Open Forests
5 Agricultural fallow
6 Cultivated land
7 Scrub/ Degraded forest
8 Built up area
9 Barren Land
10 Rocky waste lands
INDEX
Source : Author
Ch
ap
ter IV: E
stima
tion
of F
orest C
ov
er an
d C
ha
ng
e Detectio
n A
na
lysis
84
1 2 3 4 5 6 7 8 9 10 1997 Total
1997-
2012Land cover class
Reser &
rivers
Dry river
bed
Mod.dense
forest
Open
forest
Agri
fallow
Cultivated
land
Scrub/degr
forestBuilt up
Barren
land
Rocky
waste
1 Reservoir and rivers 20.83 6.82 0.48 1.15 0.30 0.15 0.68 0.18 2.81 0.03 33.43
2 Dry river bed 1.57 1.72 0.09 0.30 0.01 0.00 0.06 0.10 0.69 0.13 4.66
3 Moderately Dense forest 1.60 2.00 27.27 55.59 14.43 2.43 25.43 13.81 11.16 14.85 168.56
4 Open Forests 0.18 0.59 22.08 42.28 8.43 0.66 13.97 11.81 4.34 13.88 118.24
5 Agricultural fallow 0.39 1.19 1.26 13.15 9.46 1.63 6.73 6.52 3.64 7.03 51.00
6 Cultivated land 0.59 0.13 0.15 1.09 1.07 0.58 0.58 0.44 0.22 0.01 4.84
7 Scrub/ Degraded forest 0.42 1.29 1.63 5.75 2.17 0.43 3.33 2.46 1.33 2.25 21.06
8 Built up area 0.12 0.49 0.30 4.45 2.98 0.44 1.87 2.98 0.81 2.70 17.16
9 Barren Land 0.00 0.18 0.32 4.01 1.29 0.17 1.16 1.19 1.20 2.08 11.60
10 Rocky waste lands 0.01 0.13 0.20 6.85 2.61 0.23 3.28 1.79 1.48 5.09 21.66
2012 Total 25.70 14.53 53.79 134.61 42.75 6.73 57.08 41.29 27.68 48.06 452.22
Change Sq km -7.73 9.87 -114.77 16.37 -8.25 1.89 36.02 24.13 16.08 26.40
Change % -23.12 211.80 -68.08 13.84 -16.17 39.04 171.03 140.61 138.62 121.88
Table 4.6 Overall change in LULC pattern of the study area
85
KHADAKWASALA IRRIGATION PROJECT DIVISION
Ch
ap
ter IV: E
stima
tion
of F
orest C
ov
er an
d C
ha
ng
e Detectio
n A
na
lysis
2012 1 2 3 4 5 6 7 8 9 10 1997
1 0.623 0.204 0.014 0.034 0.009 0.005 0.020 0.005 0.084 0.001 1
2 0.336 0.369 0.020 0.064 0.001 0.000 0.013 0.022 0.147 0.028 1
3 0.010 0.012 0.162 0.330 0.086 0.014 0.151 0.082 0.066 0.088 1
4 0.002 0.005 0.187 0.358 0.071 0.006 0.118 0.100 0.037 0.117 1
5 0.008 0.023 0.025 0.258 0.186 0.032 0.132 0.128 0.071 0.138 1
6 0.121 0.026 0.032 0.224 0.220 0.121 0.119 0.090 0.046 0.001 1
7 0.020 0.061 0.078 0.273 0.103 0.020 0.158 0.117 0.063 0.107 1
8 0.007 0.029 0.018 0.259 0.174 0.026 0.109 0.174 0.047 0.158 1
9 0.000 0.016 0.027 0.345 0.111 0.015 0.100 0.103 0.103 0.179 1
10 0.000 0.006 0.009 0.316 0.120 0.011 0.151 0.082 0.068 0.235 1
Table 4.7 Land cover change : Transition Probability Matrix- 1997-2012
86
KHADAKWASALA IRRIGATION PROJECT DIVISION
1 Reservoir and rivers
2 Dry river bed
3 Moderately Dense forest
4 Open Forests
5 Agricultural fallow
6 Cultivated land
7 Scrub/ Degraded forest
8 Built up area
9 Barren Land
10 Rocky waste lands
INDEX
Source : Author
Ch
ap
ter IV: E
stima
tion
of F
orest C
ov
er an
d C
ha
ng
e Detectio
n A
na
lysis
87
Chapter IV : Estimation of Forest Cover and Change Detection Analysis
Markov chain model aim at predicting the spatial distribution of the specific land use
land cover classes in later year by utilizing the knowledge gained from the previous
years. Markov chain is spatial transition based models and one of the most accepted
methods for modeling land use land cover changes (LULCC) using current trends.
Markov chain models are particularly useful in the geographical studies which are
mainly concerned with problems of movements or change. Markov chain models are
neat and elegant conceptual devices for describing and analyzing the nature of
changes generated by the movement or change by particular variables. It also useful
for forecast the future changes. Markov chain method analyses a multiple images and
outputs a transition probability matrix. The transition probability matrix shows the
probability that one land use class will change to others. The transition area matrix
tells the number of pixels that are expected to change from one class to the other class
over the specified period (Eastman J.R. 2006).
Land use change transition probability in Markov analysis indicates the
probability of making a transition from one land use class to another within a two
discrete times. Transition probability matrix is produced by multiplication of each
column in the transition probability matrix to the number of cells of corresponding
land use in the in the later image.
4.6.1 Transition of land use and land cover change process in the study area
The Transition Probabilities governing the period 1997-2012 are calculated.
Table no 4.7 shows Transitional Probabilities (TP’s) between 1997 and 2012. For
instance transition probability from moderately dense open to open forests is 0.220
and to scrub or degraded forests is 0.103 and settlement is 0.120 and so forth upto the
year 2027. This computation is based on the assumption that the land use and land
cover change process is Markovian.
Analysis of the LU/LC pattern during 1997, 2008 and 2012 using satellite
derived maps it is observed that, socio-economic drivers mainly residential
development have influenced the spatial pattern of forests.