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GIS mapping report of mangroves of Indus Delta
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MAPPING MANGROVE FOREST RESOURCES OF INDUS DELTAIC REGION USING SATELLITE
REMOTE SENSING & GIS TECHNIQUES
1. INTRODUCTION
Mangrove forest is a diverse group of predominantly tropical
trees, shrubs and associated flora and fauna and is an
integral part of the inter-tidal zones of the coastal
environment. It is one of the most precious resources that
occur in tropical marine ecosystems and provide a range of
valuable forest products and are an important source of
wood, fuel wood, charcoal and fodder. These provide shelter
and serve as breeding grounds for a variety of species of
fish, shrimps and marine habitat as well as for certain
species of birds and mammals. Shrimps are one of
Pakistan’s important export commodity earning US $ 100
million annually. Moreover, mangroves stabilize the
shoreline from erosion, storm damage and wave action, help
in minimizing damage to property and loss of human life.
Therefore, great ecological and economic importance is
attached to the mangrove forest.
In Pakistan, the mangrove forests are found all along the
muddy Coast of Sindh at Karachi Harbour area and in the
Indus Deltaic region. Other smaller mangrove forests are
found along the Makran Coast of Balochistan, in three small
isolated pockets at Miani Hor (Sonmiani Bay), Kalmat Khor
and Jiwani Lagoon (Gwatar Bay). The 270 km Coastline of
Sindh, extend from Cape Monze to Indo-Pakistan border,
along the Arabian Sea is studded with dense to sparse
mangrove forests. The mangrove forest of Indus Delta is the
2nd largest mangrove ecosystem in the sub-tropics world.
This ecosystem is under severe environmental stress and is
under degradation due to anthropogenic distribution. The
historical record indicates that the mangroves were
distributed over a very large area in the Indus Deltaic region,
but during the past five decades, a significant change has
been observed in mangrove forest area. This ecosystem has
suffered a great damage due to human and natural
interventions, like;
The reduced flow of sweet water and silt from the
Indus River,
Intrusion of seawater,
Meandering and erosion of creeks,
The gradual increase in sea level,
Remote Sensing & GIS Applications Division of SUPARCO, June 2009
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
The inflow of pollutants,
Grazing and browsing by camels and buffaloes,
Cutting of mangroves for fuelwood collection,
The coastal process and
The cyclones.
The mangroves grow best where an adequate fresh water
supply is available, with constant injections of nutrients and
salt from the upland catchments areas. The reduced inflow
of fresh water downstream Kotri Barrage due to construction
of dams and reservoirs on Indus River and on other large
rivers for agricultural needs and for the production of
hydroelectric power, increasing the salinity of both the
surface water and sediments load; and thus affecting the
growth of mangrove plantation. Out of eight mangroves
species, only one mangrove specie, Avicennia marina
(Teemer) – a high salt tolerant specie is present in the
deltaic region, which covers about 92% of total mangrove
forests area, the other seven species have been seriously
affected by changing environmental conditions.
The mangrove forest is an important source of fuel wood for
people, mostly fisherman living along the coastal belt. Over
60% of the local population use Avicennia marina (Teemer)
as their major source of fuel. Avicennia leaves are excellent
fodder for animals and the villagers collect their leaves for
feeding of cattle, sheep and goats. Human activities induced
on the Coast of Karachi for urban development, which could
further degrade the local mangroves. Additionally, the
mangroves along the Coast of Karachi are also facing
problems of pollution from sewerage water and industrial
wastes coming from Lyari and Malir Rivers and from Gharo
Creek to Indus Delta and from the oil and bilge waste
discharged by ships visiting Karachi and Bin Qasim Ports
and as a result, they are suffering from environmental
degradation and are deteriorating at many places.
Mangrove forest is the major ecological features in the Indus
Deltaic region and playing an important role in the
biodiversity and breeding ground for shrimps. Therefore,
there is a need to monitor this ecosystem and assess the
qualitative and quantitative changes occurring in the
mangrove ecosystem using advanced technology like
satellite remote sensing. The Satellite Remote Sensing
(SRS) offers a rapid and non-intrusive means of making
large scale measurements on a variety of mangrove
parameters. SRS data have been successfully used to
assess and map the mangrove forests and other coastal
features in the coastal areas of Pakistan, to assess and
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 20092
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
monitor deforested or afforested areas, to examine
mangrove zonation, to plan aquaculture sites, and to monitor
and map oil spills areas. Therefore, on the request of
Coastal Forest Division (CFD) of Sindh Forest Department
(SFD), a study was initiated with the aims to accurately map
and assess the coastal resources of Sindh, especially the
current status of mangrove forests, along the Coast of
Karachi and in Indus Deltaic region. A similar kind of study
was conducted for the CFD of Sindh in 2005, with the aim to
assess and map the mangrove forests and other coastal
features in the lower part of Indus Delta, from Dabbo Creek
to Sir Creek, using SPOT XS data of January 2005. The
current study is an extension of the previous study, covering
the entire Coast of Sindh from Cape Monze to Sir Creek,
and using the latest SPOT XS data of Nov. 2008.
2. AIM OF THE PROJECT
The current study is aimed to map and assess the mangrove
forests cover and other coastal features in the Indus Deltaic
region and in Karachi Harbour area, using Satellite Remote
Sensing and GIS techniques. The assessment includes
collection of reliable and up-to-date information on the
current status of mangrove forests and other coastal
features along the entire Coast of Sindh, including the
Karachi Harbour area and Indus Deltaic region; and to
monitor changes taking place in the mangrove forest of
Indus Delta.
3. DESCRIPTION OF STUDY AREA
The study area constitutes the entire Coast of Province of
Sindh lies, between longitude 66°50`E to 68°30`E and
latitude 23°40`N to 24°55`N, covering the coastal areas of
Karachi, Thatta and Badin Districts and consists of Indus
River delta and the adjacent belt of low lying areas and
shallow depressions. The Coast of Sindh extends from Cape
Monze in the west to Indo-Pakistan border in the east,
covering a length of 270 km, along the Arabian Sea. This
coast has been divided into the western coast and the south-
eastern coast. The western coast extending from Hub River
fall near Cape Monze to Karachi consists of rocky shores,
sandy beaches, backwater, estuaries and mangroves. The
south-eastern coast consists of 17 major creeks and
innumerable minor creeks of the delta and inshore waters
with tidal mud flats, creek channels, sandy areas and
fringing mangroves, which have the usual mixing of fresh
water from the Indus River and salty water from the Arabian
Sea. The Indus River deltaic system is one of the largest
deltas of the world, situated on the southeastern border of
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 20093
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
Pakistan near Rann of Kutch (India). It is a typical fan
shaped delta, built by the discharge of large quantities of silt
washed down by the Indus River from the Karakoram and
Himalaya mountain ranges. The coastal zone of the delta
from the shoreline to the extent of mud flats covers an area
of about 9,930 sq. km. The mangrove forest of Indus Delta is
the 2nd largest in the sub-tropics world, dominated by
mangrove specie Avicennia marina (local name Teemer),
which covers about 92% of total mangrove forests area.
Other three mangrove species: Rhizophora mucronata
(Kumri), Ceriops tagal (Kiriri) and Aegicerus corniculatum
(Chaunr) are also present in some parts of the Indus Delta,
but on very small area, covering about 8% of total
mangroves area. The location of the study area is marked on
satellite image mosaic of the Province of Sindh, shown in
Figure 1.
4. MATERIALS USED
In this study, following materials have been used:
i) SPOT XS digital data acquired in Oct. / Nov.
2008, covering the entire Coast of Sindh from
Karachi to Sir Creek
ii) Historical SRS data for comparison and for
monitoring dynamic changes in the area
iii) Reference maps for Image geo-coding / geo-
referencing and annotation
iv) Ground surveys information.
5. METHODOLOGY
For coastal resource assessment, SPOT XS digital data of
2008 were processed using digital image processing and
Geographic Information System (GIS) techniques. SPOT
XS images (raster data) were extracted, enhanced and
displayed in color composite forms. Image geo-coding was
applied on the raw enhanced images to rectify the images to
the real world coordinate systems. In order to compile a
single image of the entire study area, all the SPOT rectified /
geo-coded images were mosaiced digitally. Colour balancing
was applied to create seamless joins between them. To use
only the requisite area of the Indus Delta, the boundaries of
the extent of mud flats (coastal areas) were digitized and the
areas lying outside were masked. This enabled delineation of
accurate landuse / landcover classes. SPOT XS color
composite image mosaic of Coast of Sindh covering Karachi
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 20094
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
Harbour area and the entire Indus Deltaic region covering all
major and minor creeks is shown in Figure 2. The coastal
features within the study area, like different densities of
mangrove forests (dense, medium and sparse), the position
of creeks / channels, mudflats and sandy areas, etc have
been digitized by on-screen digitization technique using
AutoCAD Map 2000, and using the image mosaic of Indus
Delta and the GIS based vector layers of these coastal
features have been developed. Small towns / villages and
road network, as seen on the SPOT images were also
digitized and delineated and annotated to produce another
vector layer for integrating with digitized layers of mangrove
forests, sandy area, mudflats and creeks / channels layers.
It may be mentioned that the quantitative assessment of
mangrove forest and other coastal features are not entirely
based on interpretation of satellite images, it also require the
analysis of the various components of whole environment
prevailing in the respective study areas, such as background
knowledge of the area, local environmental conditions and
the probable factors influencing the ecosystem, e.g., human
activities, natural hazards, conservation measures, etc.
Therefore, for background knowledge of the area, historical
available Landsat TM data of 1989 & 1998; and SPOT XS
data of 2003 & 2005 were analysed. Ancillary data and
other ground based information have also been collected.
For this purpose, the ground surveys of western part of Shah
Bandar area and north-western part of Keti Bandar were
conducted on 6th and 7th November 2008, respectively, with
the assistance of Divisional Forest Officer (DFO) and Range
Forest Officers (RFO’s) of the respective sections of Coastal
Forest Division. The surveys were supported by GPS, the
previous categorized landcover maps based on SPOT XS
data of 2003 and 2005; of ground survey’s sites, extensive
photography and field survey proforma. Information collected
through ground observations and from the RFO’s and other
staff members of Coastal Forest Division were also
incorporated for improvement and verification of satellite
based results. GIS based mangrove forests map of Indus
Deltaic region, i.e. from Karachi to Sir Creek, has been
compiled using map composition and GIS techniques, at
1:250,000 scale and is shown in Figure 3. Detailed maps of
some parts of Indus Delta, viz-a-viz from Korangi Creek to
Paitiani Creek, Paitiani Creek to Hajamro Creek including
the town of Keti Bandar, mouth of Indus River covering
Turshian River to Kharak Creek, Shah Bandar area and
northern part of Sir Creek covering Shah Samando Creek
and western part of Tidal Link, have been compiled at
1:50,000 scale and are included in the report as Annex - I, 2,
3, 4 & 5, respectively.
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 20095
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
6. RESULTS AND DISCUSSIONS
The enhanced satellite image of the coastal belt of Sindh,
shown in Figure 2, represents the current status of
mangrove forest and other coastal features in the Indus
Deltaic plain. On this image, the mangroves appear in
different shades of red, depending upon their densities and
canopy cover. The dense mangroves, which has large
canopy cover and are in good and healthy conditions, i.e.,
having high chlorophyll concentration appear with bright red,
due to high reflectance in the near-infrared band. The
medium density mangroves appear in medium red and
scattered or sparse mangroves appears in yellowish red
colour because of less canopy cover and reflectance of
vegetation plus the reflectance of ground soil. Natural
vegetation, which grow in water or in moist soil appear with
brownish red colour, because of the presence of moisture in
the soil has appreciably reduced the solar radiation from
such area on account of typically low reflectance of water /
moist soil in the near infrared band. Mudflats appear in gray
and the dry sandy beaches due to high reflective materials
(sandy / silty soil) appear with bright white tone. The water
has low reflectance in the visible, as well as in the infrared
channel, due to absorption of solar radiation and due to this
reason the deep sea appears black, showing no
sedimentation or turbidity in the water, whereas the near
shore water and creek / channels are in dark to light blue
color, depending upon concentration of sediments / turbidity
in the seawater.
The mangrove ecosystems of Karachi Harbour area and of
the Indus Deltaic region are undergoing changes, due to
natural and human interventions, therefore, regular
monitoring and mapping of mangrove ecosystem is
necessary for preservation and protection of such precious
resources from further degradation. For this purpose, the
mangrove forest map of the entire Coast of Sindh, based on
current SPOT XS data of November 2008, have been
prepared using SRS& GIS based techniques, and is shown
in Figure 3. This map represents the different densities of
mangrove forests and other coastal features like sandy
areas, mud flats, creek / channels, etc, along the Coast of
Sindh. The mangroves of Sindh are discussed in details as
below:
6.1 The Coast of Karachi
The Coast of Karachi covers the area from Cape Monze to
Chinna Creek. The area from Cape Monze to Sand Spit is a
rocky - sandy barren coast and devoid of vegetation. The
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 20096
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
mangroves in the Karachi Harbour area are found in the
backwaters of Manora Channel and in Chinna Creek. The
enhanced SPOT XS image of November 2008 of Karachi
Harbour area is shown in Figure 4. This area has well
developed and close canopy mangrove forests, especially at
Sand Spit and Manora Island. The only mangrove specie
Avicennia marina (Teemer) has been found in this area.
Based on SPOT image of 2008, a GIS based landuse /
landcover thematic map, showing mangrove forest and other
coastal features like marine algae, creeks / channels, sandy
area, salt work areas, different types of water (deep water,
shallow water, turbid water, highly turbid water), etc, has
been prepared and is shown in Figure 5. From the
landcover thematic map, the area under each mangrove
class has been estimated, and is given in Table I. The
mangrove forest at Karachi Harbour area are spread over an
area of 1,160 hectares (ha), out of which the dense
mangroves cover an area of 630 ha, medium densities
mangroves on 385 ha and sparse mangroves on 145 ha.
The marine algae spread over an area of 920 ha, sandy area
covers 1,270 ha and muddy areas occupy 710 ha.
The Coastal areas of Karachi are facing various problems,
especially the Karachi Harbour area, which has almost all
forms of pollution that might be expected within an urban
environment close to the seaport. A large amount of
polluted water-sewerage water and industrial waste of
Karachi City, coming from the Lyari River into the Manora
Channel, increase the marine pollution in the area. This
polluted water may provide nutrients to mangroves and
decrease the salinity level in the channel and seems locally
to their benefit, but increase the pollution in the backwater of
Manora Channel, and produced the marine algae. The
increase in marine algal cover is very prominent in the
current satellite image of 2008, as compared with the
satellite image of 1989, which appears with the dark brown
patches in satellite images. The marine algae were
spreaded over mudflats and in backwaters of Manora
Channel in mangroves harvesting areas. Oil pollution is also
increasing on the Coast of Karachi, particularly in the
backwaters of Manora Channel and in Chinna Creek, due to
increase in the ship traffic. The surface deposits of crude oil
and bilge wastes are interspersed in seawater but these
materials seem to have little or almost no effect on structure
and functioning of the mangrove forest. The human
activities going-on, at the Coast of Karachi for urban
development, like the development of land for construction in
Gizri Creek and in Chinna Creek near Boating Basin, is
further reducing the growth of local mangroves.
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 20097
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
TABLE – I: 6.2 The Indus Deltaic Region
The Indus Delta spread from Korangi Creek to Sir Creek
consists of 17 major creeks, namely; the Korangi Creek,
Phitti Creek, Waddi-Khuddi Creek, Khai Creek, Paitiani
Creek, Dabbo Creek, Chhan Creek, Hajamro Creek,
Turshian River, Khobar Creek (Jangh River), Qalandri River,
Gahbar Creek, Khar Creek, Kharak Creek, Pakhar Creek,
Kajhar Creek and Sir Creek; and numerous minor creeks,
mudflats, sandy areas and tidal creeks that are lined with
dense to sparse mangrove forests on sand-silt substrate.
The enhanced SPOT XS mosaic image and GIS based
mangrove forest map of Indus Deltaic region based on
SPOT XS data of 2008 are shown in Figures 6 and 7,
respectively. This map represents the current status of
mangrove forests in the Indus Deltaic region. On this
mangrove forest map, the dense mangroves are represented
by magenta, medium density mangroves by green and
sparse mangroves by orange colour, mudflats are shown in
gray and dry sandy beaches are delineated with yellow
colour. Small towns / villages, the road network, as identified
on SPOT XS images are marked and delineated on the
mangrove forest map of Indus Delta. The area under each
mangrove class has been estimated from the landcover map
and is given in Table – II. The total mangrove forest area in
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 20098
Sr.No.
Class ColourArea in
HectaresArea in
Sq. Kms%
1Dense Mangroves
Magenta 630.00 6.35 3.94
2Medium Mangroves
Green 385.00 3.85 2.41
3Sparse Mangroves
Orange 145.00 1.45 0.91
4 Marine AlgaeYellowish Green
920.00 9.20 5.75
5 Sandy Area Yellow 1,270.00 12.70 7.94
6 Muddy Area Gray 710.00 7.10 4.44
7 Deep WaterDark Blue
3,765.00 37.65 23.55
8Shallow Water
Navy Blue
7,670.00 76.70 47.97
9. Turbid WaterLight Blue
495.00 4.95 3.09
Total 15,990.00 159.90 100.0
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
Indus Deltaic region are estimated to be 106,480 hectares
(ha), out of which the dense mangroves are spread over an
area of 25,320 ha, medium density mangroves on 34,700 ha
and sparse mangroves are spread on 46,460 ha, sandy
area covers 9,100 ha, and mud flats occupy 183,250 ha.
The historical satellite data provide great means in analyzing
the successive changes occurring in the landuse / landcover
features and in the natural resources, e.g., mangrove forest
cover. Therefore, historical Landsat TM data of 1989 & 1998
and SPOT XS data of 2003, available in digital form in
SUPARCO archives were used for comparison and analysis.
These data sets have also been used to study and
understand the coastal processes and their impacts on tidal /
inter-tidal zones and in low lying areas of Thatta and Badin
Districts. From the analysis of historical SRS data, it is
observed that the mangrove forest was spreaded on very
small area in 1989, which increased gradually and became
doubled in 2008. The increase in mangrove forests area is
the result of plantation of fast growing and high salt deserted
mangrove species, Rhizophora mucronata (Kumri), and also
of Avicennia marina (Teemer) in the inter-tidal zones of the
Indus Delta. However, the mangrove forest are deteriorated
by various human induced factors like; indiscriminate use of
TABLE – II: Area Summary Report of Mangrove Forest of Indus Delta based on SPOT XS Data of 2008
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 20099
Sr.No.
Class ColourArea in
HectaresArea in
Sq. Kms%
1Dense Mangroves
Magenta 25,320 253.20 4.22
2Medium Mangroves
Green 34,700 347.00 5.78
3Sparse Mangroves
Orange 46,460 464.60 7.74
4 Sandy Area Yellow 9,100 91.00 1.52
5 Mud Flats Gray 183,250 1,832.50 30.54
6
Creeks / Channels/
Sea Water
Navy Blue
301,170 3011.70 50.20
Total 600,000 6,000.00 100.0
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
these forests for firewood, timber, fodder and fishing related
products, water pollution and the reduction in flow of fresh
water and increase in salinity in the Indus Deltaic region.
The mangrove forest in the Indus Delta have been observed
in two compact blocks, the northern block and the southern
block and middle part covers mouth of Indus River, which is
barren and devoid of vegetation, as discussed below:
6.2.1 The Northern Block of Mangrove Forest
The northern block of the Indus Delta covers the area
between Korangi Creek to Chhan Creek. This area has well
developed dense mangrove forest stands on sand / silt
substrate, numerous tidal creeks, mudflats and sandy
beaches. The sandy areas are completely barren and behind
the sand, extensive mudflats are covered with varying
densities of mangrove forests (dense, medium and sparse),
with close canopy and vigorous appearance, as shown in
Figure 8(a) and its categorized landcover map is shown in
Figure 8(b). The northern part of this segment is under the
control of Port Qasim Authority and is a protective zone;
because of this, the area has well developed mangrove
forest stands of dense canopy cover. The major part of this
segment is covered with mangrove specie Avicennia marina,
but other mangrove species Rhizophora mucronata, Ceriops
tagal and Aegicerus corniculatum have also been observed
in this region. Tall trees of Avicennia marina, 10 – 12 ft, with
large canopy cover have been observed in this part of the
delta. Mangroves specie Aegicerus corniculatum is also
observed in this area at Waddi-Khuddi and Dabbo Creek,
and are found in good and healthy conditions. Ceriops tagal
is naturally present in the area. Its leaves are very similar to
Avicennia marina, but have small canopy cover and are of
very small heights, upto 2 – 4 ft. Normally, A. marina specie
attains 10m heights in 30 – 35 years in regularly inundated
areas but become stunted in hostile conditions. The ground
views of mangroves species Avicennia marina, Rhizophora
mucronata, Ceriops tagal and Aegicerus corniculatum are
shown in Figures 9 (a, b, c & d), respectively.
On comparison of satellite images of 1989, 1998 and 2003
with 2008 image of the northern block of mangroves, no
major change has been observed in this block, except in the
Korangi-Phitti Creek area, along the eastern Coast of
Karachi. The mangroves in this part of the delta are
harvested for cattle and camel fodder during the dry season,
as the mangroves represent the only green foliage present in
the region during the dry winter season. Mangrove trees are
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 200910
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
also cut for fuel purpose and thus this part of the delta is
under influence of heavy grazing pressure during the dry
winter season by the local inhabitants.
The second major urban industrial center of Karachi is
located along the eastern Coast of Karachi near Indus Delta
and another small urban industrial center in the area is
Gharo in Thatta District. The Malir River contributes a large
amount of polluted sewerage water and industrial wastes of
eastern part of Karachi City into the Gizri, Korangi and
Ahsan Creeks. A large number of textile and other
industries, located at Gharo in Thatta District also increase
the marine pollution in the area. This is adversely affecting
the ecology of the estuary and creek areas, and marine
algae is also growing in the mangrove habitat in the water of
Korangi - Phitti Creeks, indicates the presence of increased
marine pollution in the creek waters. The dark brown
patches of marine algal cover were very prominent in the
current SPOT image of 2008, on the mud flats and in the
waters of Gizri, Korangi, Ahsan and Gharo Creek areas in
the mangroves habitats. This has also been identified during
the ground survey of area near Rehri Goth and Lat Basti.
On comparison of satellite images of 1989, 1998, 2003 and
2008, it was observed that the marine algal cover in this part
of delta has been increased between 1998 and 2008, which
is due to increase in marine pollution in the area. This
polluted water thus affecting the growth of young mangrove
plantations and these are therefore dying.
6.2.2 The Middle Part of Indus Delta
The middle part of study area covers the mouth of Indus
River, covering the area from Hajamro Creek to Khar Creek,
and the town of Keti Bandar, which is a well-known small
fisherman’s village, situated within the delta to the north west
of the major Indus spill River. This part of Indus Delta is
almost barren and lies under the control of Sindh Board of
Revenue. SPOT XS image of this part and its categorized
map is shown in Figures 10 (a & b), respectively. In the
past 50 years, the construction of dams and barrages and
increased utilization of fresh water from the Indus River for
irrigation and for generation of hydroelectric power, the Indus
River now mostly discharges fresh water to the sea only
during monsoon flooding. During the other remaining
months of the year, the Indus River has very less or no
water. The reduced supply of fresh water downstream
accelerated the pace of seawater intrusion into the riverine
tract, which goes up about 65 km, upto Thatta – Sujawal
Bridge. The seawater intruded initially the tidal zone and
slowly and gradually flowed upstream in the main course of
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 200911
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
Indus River, which brinks ecological disaster in the Coastal
areas of Sindh, especially in the Thatta and Badin Districts,
where thousands of hectares of cultivated lands have been
converted into waterlogged and under high salinity. The
effect of intrusion and the increase in soil salinity appears
very prominent in the current SPOT image of 2008 with
white tone. The reduced inflow of fresh water ostensibly
increasing salinity of both the surface water and sediments
load and decreasing the nutrient supply from the terrestrial
fresh water in the Indus estuary, there by killing mangrove
communities, as well as the riverine forests near the mouth
of the Indus River. With regard to sea intrusion towards the
land area, the tidal boundaries have been drawn from
historical SRS data of 1976, 1989, 1998 and 2003, and
integrated with SPOT image of 2008. From integration, it is
observed that the impact of coastal process has been more
at the middle and on the south-eastern parts of the delta,
especially from Keti Bandar to Dhands areas in Badin
District and very little variation has been seen on the north-
western part of the delta.
To create biodiversity, the Sindh Forest Department with the
financial assistance of World Bank, has planted four
indigenous mangrove species in 2002 (mentioned above), at
suitable sites in the inter-tidal zones, in area between Chhan
Creek and Hajamro Creek, situated in the north-west of town
of Keti Bandar. This area is now under sparse mangrove
vegetations of 2 – 5 ft height. The ground views of mangrove
nursery, new planted mangrove trees, medium density
mangroves and dense mangrove forests observed near Keti
Bandar are shown in Figures 11 (a, b, c & d), respectively.
The CFD also planted high salt deserted mangrove specie in
1986 – 1988, and further in 1999 – 2002 in the tidal zones,
near the Sanhri and Gahbar Creeks. This area is closed to
open sea and the mangroves in this area are at an
unapproachable distance; and are therefore, protected from
harvesting. It was also observed that the land accretion has
also taken place, after plantation of mangroves on the
mudflats between Sanhri and Gahbar Creeks. The increase
in mangrove forest area and land accretion taken place in
this part of delta are shown in the zoomed satellite images in
Figures 12 (a & b), respectively. This shows that plantation
of mangroves on barren mud flats, especially near the
coastline, will help in binding the soil and protect the land
from extensive erosion by sea tide actions.
6.2.3 The Southern Block of Mangrove Forest
The southern block of Indus Deltaic region covers the area
from Shah Bandar to Pateji Dhand and from Khar Creek to
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 200912
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
Sir Creek and is close to Rann of Kutch of India. This zone
is under the protection of Coastal Forest Division. Another
small well-known fisherman village, Shah Bandar is situated
to the north-east of the major Indus spill River within the
delta. The SPOT XS image of the southern block of Indus
Deltaic region and its categorized landcover map are shown
in Figures 13 (a & b), respectively. The upper part of this
block is barren and the lower part has stunted growth of
mangrove vegetation. Under the rehabilitation plan, IUCN
and CFD planted a fast growing and high salt deserted
mangrove species, Rhizophora mucronata (Kumri) in 1986 –
1988, in the inter-tidal zone near the town of Shah Bandar.
In the satellite image of 1989, this area was under water,
and very sparse mangrove vegetation have been observed
in the lower side, which became under dense vegetation
(medium to dense mangrove plantations), as appears in the
Landsat image of 1998. In SPOT 2008 image, this area has
same medium to dense mangrove plantations of Rhizophora
mucronata of 10 – 14 ft heights. From the comparative
satellite images of 1989, 1998 and 2008, shown in Figures
14 (a, b & c), respectively, it was observed that the small
patched of mangroves in the lower side of Shah Bandar
forest have been deteriorated, which may be due to high
salinity in the area and non-availability of fresh water. The
high salinity on the mud flats and degraded mangroves as
observed in the ground survey of the area are shown in Figs.
14 (d & e), respectively. Mangrove nursery of R. mucronata
established in the inter-tidal zone near the old town of Shah
Bandar by CFD and sparse mangrove trees of R.
mucronata; and dense and medium density mangrove forest
of A. marina observed in the western part of Shah Bandar
area are shown in Figures 15 (a, b, c & d), respectively.
In the recent past (in 1995), a Tidal Link drain, which is the
main outfall component of Left Bank Outfall Drain (LBOD)
has been constructed, with the primary aim to reclaim the
agricultural lands of Sanghar, Nawabshah and Mirpurkhas
Districts by reducing the watertable, thereby reducing the
salinity, and drain the agricultural effluents containing
excessive salts and saline water from LBOD to Arabian Sea
through Tidal Link drain and Shah Samando Creek. In May
1999, a powerful Cyclone TC – 02A devastated 160 km
Coastline of Sindh from Indian border to Keti Bandar,
including a large part of Thatta and Badin Districts and the
mangroves in the south-eastern part of delta, especially the
Rhizophora were badly effected. The catastrophic effects of
this cyclone resulted in severe damage of the Tidal Link
drain from several locations, and have greatly damaged the
ecology of the area, resulting in degradation of thousands of
hectares of agricultural land in Badin District, by increasing
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 200913
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
the waterlogging and salinity in the area. The enhanced
satellite images of 1989, 1998 and 2008 of south-eastern
part of delta near Rann of Kutch, has stunted growth of
mangrove vegetation, as shown in Figures 16 (a, b & c),
respectively. In 1989, this area has several small and large
patches of dense to sparse mangrove vegetation, the size
and canopy cover was decreased in 1998, and which was
further decreased in 2008 image, as appears in the
comparative satellite images of 1989, 1998 and 2008. The
deterioration of mangroves in this part of delta may be due to
shortage of fresh water and high salinity in the area. Sea
water salinity and turbidity is also very high in this part of the
further decreased in 2008 image, as appears in the
comparative satellite images of 1989, 1998 and 2008. The
deterioration of mangroves in this part of delta may be due to
shortage of fresh water and high salinity in the area. Sea
water salinity and turbidity is also very high in this part of the
delta, especially at Kharak, Pakhar, Kajhar and Sir Creeks.
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 200914
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
7.0 CONCLUSION AND RECOMMENDATIONS
From this study, it is concluded that:
The SPOT XS data of 2008 used in this study are
found suitable for current assessment and
development of most recent database of coastal
natural resources, like mangrove forests and
generation of GIS based mangrove forest maps of
inaccessible Coastal areas of Sindh.
In the current investigation, 20m SPOT XS data has
found useful in discriminating at least three categories
of mangrove forests (dense, medium and sparse),
through their tone and vigor and other coastal
features like mud flats, sandy and saline areas, etc.
However, due to mixed plantations, it had been
difficult to distinguish between different mangrove
species grown in the same parts of Indus Deltaic
region. It is to be noted that the satellite sensors can
discriminate mangrove zonation on the basis of
canopy cover but discriminating different species
under prevailing environmental conditions cannot be
made.
From the analysis of SPOT XS data of 2008, it is
estimated that the mangrove forests are spread over
an area of 107,640 hectares along the Coast of
Sindh. Out of which, the mangroves in Karachi
Harbour area is spread over an area of 1,160
hectares and about 106,480 hectares in the Indus
Deltaic region.
After a thorough study of all mangroves sites in the
study area, it is concluded that the decrease in
mangrove forest area has been observed in some
specific places, which could be due to indiscriminate
use of mangroves trees for grazing and fuel purposes
(due to increase in the prices of oil, wood, charcoal,
etc.) by the local inhabitants, shortage of fresh water
supply, as well as affect of cyclones / hurricanes.
However, it was also noted that the deterioration has
been taken pace at a very small scale and
afforestation have taken placed at large scale. The
conservation measures taken by Coastal Forest
Division in collaboration with other departments have
improved the growth of mangroves in the delta.
The plantation of high salt tolerant and fast growing
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 200915
Mapping Mangrove Forest Resources of Indus Deltaic Region using Satellite Remote Sensing & GIS Techniques – A Collaborative Project of Coastal Forest Division of Sindh & SUPARCO
mangrove specie, Rhizophora and Avicennia, carried
out in the inter-tidal zones of Indus Delta, has
provided positive results. This could not only increase
the forest area, but also help in binding the soil and
protect the coastline and delta from extensive erosion
through high tides.
The GIS based mangrove forest map of Indus Delta
at 1:250,000 and detailed maps at 1:50,000 scale of
different parts of delta are of great significance in the
planning and management of coastal areas of Sindh.
These maps can provide important and useful
information regarding rehabilitation and/or
conservation of mangrove forests, especially the
details maps at 1:50,000 scale, could help Coastal
Forest Division in identifying appropriate sites for
plantation of mangroves in barren areas of the delta,
because a large part of mud flats near the mouth of
Indus River and in the upper eastern part of delta are
barren.
From the analysis of temporal SRS data of 1989,
1998, 2003, 2005 and current 2008 data, it was
observed that the surface salt accumulation and
dryness in the deltaic region have been increased due
to non-availability of fresh or sweet water from Indus
River and intrusion of seawater in the Indus Delta
creek system through the riverine tract and channels.
The increase in waterlogging and salinity in inland
areas of Thatta & Badin Districts, indicate that the
seawater is intruding in ground water aquifers and
destroying the agricultural land. Therefore, there is a
dire need to increase the inflow of fresh water in Indus
downstream, which would certainly help in decreasing
the salinity level in the deltaic region and turbidity in
the seawater and provide nutrients for the growth of
mangrove plantations from the terrestrial (fresh) water
runoff, because hyper-salinity and turbidity are
harmful to fish production and marine life.
From the analysis of temporal SRS data, it was also
observed that the dryness in the eastern part of the
delta near Tidal Link drain has been increased due to
intrusion of seawater through the Shah Samando
Creek and from breaches occurred in Tidal Link,
which deteriorated the dhands and the surrounding
environment.
A Collaborative Project of Coastal Forest Division of Sindh Forest Department and SUPARCO, June 200916
Recommended