Mangroves of Indus Delta 2008

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


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



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



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.



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



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.



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


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


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


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


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



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



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



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



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.



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



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.


Documents

Mangroves of Indus Delta 2008