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Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 1
LANDSCAPE PATTERN ANALYSIS THROUGH METRICS
Vishnu Bajpai1 , Ramachandra T. V.1,2,3,*
1. Centre for Ecological Sciences, Indian Institute of Science.
2. Centre for Sustainable Technologies, Indian Institute of Science
3. Centre for infrastructure, Sustainable Transportation and Urban Planning, IISc
*Corresponding author: [email protected]
Abstract
Land-use and land-cover (LULC) refers to the changes due to activities of humans, linked with global
Environment and climate change. Conditions in environmental systems with large measures of urbanization
are correlated, such as population density with built-up area .Urban sprawl refers to the unplanned,
uncontrolled spreading of urban area adjoining the edge of a city caused as a result of urbanization.
This study investigated the spatio-temporal dynamics of Bangalore’s landscape during the period (1999-
2008) using multi-temporal satellite images. Bangalore Administrative Boundary along with 10 km circular
buffer was taken as the study area. A maximum likelihood classification algorithm was used to classify the
images. After classification land cover statistics were evaluated for each class. The classified image of each
year was divided into 8 directions and then each direction into 13 concentric circles. Landscape metrics
were computed to describe the landscape pattern used in this study. The landscape metrics enabled the
description of the spatial regularities and trends, and constitute useful indirect indicators of the impact of
abrupt landscape changes. The study shows that there has been a 13.35% growth of pervious area during
the study period.
Keywords: Urban Sprawl, Urbanization, Landscape metrics
1. Introduction
Urbanization comprises population immigration to an already existing urban area that results in expansion
of that area at the cost of natural land.Urbanization has resulted in increased density in affected areas,
most notably in growing cities, and is often accompanied by a multitude of problems or consequences. One
of the most notable of these problems is urban sprawling. The extent of urbanization is called the sprawl
that drives change in land use patterns. Various studies were attempted on urban sprawl (The Regionalist,
1997; Sierra Club, 1998). In the developed countries (Batty et al., 1999; Torrens and Alberti, 2000; Barnes
et al., 2001, Hurd et al., 2001; Epstein et al., 2002) and also in developing countries for example China
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 2
(Yeh and Li, 2001; Cheng and Masser, 2003) and India (Jothimani, 1997 and Lata et al., 2001; Sudhira et
al..,2003) have studied urban sprawl.The parameter of quantifying urban sprawl is generally the built-up
area (Torrens and Alberti, 2000; Barnes et al., 2001; Epstein et al., 2002). Urban sprawl is also referred as
irresponsible, and often poorly planned development that destroys green space, increases traffic, contributes
to air pollution, leads to congestion with crowding and does not contribute significantly to revenue, a major
concern. Analysing the sprawl over a period of time will help in understanding the nature and growth of
urbanization.
Tools including geographic information systems (GIS) and remote sensing enable land planners, managers,
and ecologists to display and quantify changes in landscape structure that result from disturbances(Turner
and Carpenter, 1998).The objective of this paper is to assess land use change in study area from 1999 to
2008 and finding the role of landscape metrics for describing the changes in urban areas over time The
study demonstrates that the application of GIS and remote sensing coupled with statistical analyses, such as
arriving at Shannon's entropy helps in studying the sprawl and identifying regions having potential for
subsequent sprawl.
2. Study area
The study area encompasses Greater Bangalore with 10 km circular buffer (fig 1). Bangalore is one of the
fastest growing cities in India and is branded as ‘Silicon Valley of India’ for heralding and spearheading the
growth of Information Technology (IT) based industries in the country.(Sudhira et al.,2007).It is capital
city of Karnataka with an area of 741 sq. km., between the latitudes 12°39’00’’ to 13°13’00’’N and
longitude 77°22’00’’ to 77°52’00’’E. The population of Bangalore is about 8 million (Ramachandra and
Kumar, 2008). It is the fifth largest metropolis in India.
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 3
Figure 1: Study area
3. Data processing and methodology
In this study Landsat TM data were used.For the study data were preprocessed using GRASS software
which involves line correction, Geometric correction. Since unsystematic geometric errors remain in
commercially available remote sensing data, geometric rectification was needed to reduce the error before
land use classification .Maximum Likelihood classifier (MLC) was then used to classify temporal RS data
into 4 Land cover (LC) classes such as urban, vegetation, water and others. This method constitutes a
historically dominant approach to RS-based automated LC derivation (Gao et al., 2004) and has become
popular and widespread in RS because of its robustness (Hester et al., 2008). After classification land cover
statistics were evaluated for each class. Detailed analysis is done by dividing the city into eight zones
North-West-West (NWW),North-North-west (NNW) North-North-East (NNE), North-East-East (NEE),
South-East-East (SEE), South-South-East (SSE), South-South-West (SSW), South-West-West (SWW),and
then 13 concentric circles of 2km were drawn from the centre. In this way classified images was divided
into 8 directions and then 13 concentric circles were cropped and finally 104 regions were obtained from
each classified images. The cropped region obtained from each classified images were used for further
computation of spatial metrics.
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 4
Figure 2: Data Processing and methodology used in this study.
Table 1: Description of metrics used in this study
Sl
No.
Indicators Formula Description
1. Mean Patch Size
It measures the average area of
all patches in the landscape.
MPS > 0
2. Mean shape
Index)
Mean shape index (MSI)
measures the average patch shape
or the average perimeter-to-area
ratio, for a particular patch type
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 5
(class) or for all patches in the
landscape
MSI >=1
3. Mean Nearest
Neighbor
Distance
where h =nearest edge to edge distance
n =total no of patches of same type
Mean Nearest Neighbor
measures average patch to patch
distance.
MNN > 0, without limit.
4. Mean
Proximity
Index)
The mean proximity index
measures the degree of isolation
and fragmentation of the
corresponding patch type
MPI >=0.
5.
Interspersion
and
Juxtaposition
Index
0 < IJI <=100
IJI =0 when the corresponding
patch type is adjacent to only 1
other patch type and the number
of patch types increases.
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 6
eik =total length (m) of edge in landscape
between patch types (classes) i and k.
m =number of patch types (classes)
present in the landscape, including the
landscape border, if present.
IJI = 100 when the
corresponding patch type is
equally adjacent to all other patch
types.
4. Results
During the study period (1999 to 2008) urban density increased in almost every direction in each circle
which showed clear urban growth in the study area. On the other hand, there has been a decrease in the
vegetation, water bodies and others. The classified images are shown in figure 3 and the statistics are listed
in table 2. Several Landscape metrices were computed in this paper (Mean Nearest Neighbor distance,
Mean Patch Size, Mean Proximity Index, Mean Shape Index and, Interspersion and Juxtaposition Index.).
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 7
Figure 3: Classified Images from 1999 to 2008
Table 2: land use statistic
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 8
Figure 4: Mean Neareast Neighbour distance
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 9
Mean Nearest Neighbour measures average patch to patch distance. The value of this index decreased
from1999 to 2008.Less value of Mean nearest neighbor distance in landscape indicates that patches are less
insular in the landscape. From 1999 to 2008 values decreased, this showed 1999 to 2008 urban patches are
more aggregated. For circle 11 from 1999 to 2000 and 2003 in SWW direction value decreased, however in
2006 value increased but again in 2008 value decreased, which showed from 1999 to 2003 the urban
patches were aggregated but in 2006 some fragmentation happened but again in 2008 decreased value of
this index showed that urban patches are more compact in 2008, this pattern is seen in almost all direction
for all circles.
Figure 5: Mean Proximity Index
MPI = 0 if all patches of the corresponding patch type have no neighbors of the same type within the
specified search radius. MPI increases as patches of the corresponding patch type become less isolated and
the patch type becomes less fragmented in distribution.The general trend is that the value of this index
increased.In 1999 in circle 2 in NNE value is low which increased in all the years. In circle 3 in NNW
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 10
direction value increased from 1999 to 2008and it is max in 2008.Increased value of this index showed less
fragmentation in the landscape from 1999 to 2008.In circle 4 in SWW value is low in 1999a slight increase
is there in 2000 and 2003 but in 2006 there is a decrease which showed fragmentation and again in 2008
value increased which showed aggregation of urban patches in 2008.
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 11
Figure 6: Mean Patch size
Mean patch size, measures the average area of all patches in the landscape. If MPS is small it indicates a
fragmented landscape.In circle 2 i.e. near the city center, the NNE value increased in 2000,2003,2006 and
it is maximum in 2008(fig 6) which showed that urban patches are fragmented in earlier years but they are
becoming more compact in 2008. For circle 4 in SWW values decreased from 1999 to 2003 which showed
the fragmentation of patches but in 2006 and 2008 value increased and maximum in 2008,which showed
the aggregation of urban patche in 2008.
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 12
Figure 7: Mean Shape Index
Shape index measures the complexity of patch shape compared to a standard shape.MSI = 1 when all
patches of the corresponding patch type are circular (vector) or square (raster); MSI increases without limit
as the patch shapes become more Irregular. In circle 1 value increased from 1999 to 2000 in all directions
and in 2003,SWW showed a drastic increase which showed that sprawl has happened there but in NNW
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 13
value decreased and in 2006 SWW value decreased in 2008 value decreased in almost every direction
(fig.7) so from 1999 to 2006 patch shapes are very irregular but in 2008 urban patches become more
regular which showed the aggregation of urban patches in 2008.For circle 5 in 2006 in SSW value goes
upto 3.5 which showed urban patches become more irregular in this direction.for circle 4 in 1999 in SSW
value is high which showed in that direction patch shapes are irregular.
Figure 8: Interspersion and juxtaposition Index
Interspersion and juxtaposition index measures the extent to which patch types are interspersed, higher
values result from landscapes in which the patch types are well interspersed (equally adjacent to each
other), whereas lower values characterize landscapes in which the patch types are poorly interspersed
(disproportionate distributionof patch type adjacencies).The general trend showed the decrease in the value
of this index from 1999 to 2008.From 1999 to 2000 not much change is visible..In 2003 all values are
between 60 and 100. In 2006 value decreased up to 30 but in 2008 value of this index showed a drastic
decrease indicating urban patches are poorly interspersed.In circle1 the values decreased in all the
directions from 1999 to 2008, which showed the aggregation of urban patches at the city center in 2008 as
we conclude from other metrics also.
Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 14
5. Conclusion
In this study we used multi-temporal analysis combined with landscape metrics for identifying the changes
of landscape pattern caused by the urbanization. Landscape metrics were very useful to detect landscape
pattern and its changes. There has been a 13.35% urban growth in study area from 1999 to 2008.Urban
patches were more dispersed in earlier years but patches are aggregating which showed that the study area
becoming more compact in 2008.
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Lake 2010: Wetlands, Biodiversity and Climate Change
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