A comparison of India and Pakistan (specific) mangroves ecosystem growth and management practices,more specifically, for the tidal and fresh water flow.

1. Response of mangroves to the change in
tidal and fresh water flow – A case study in
Pichavaram, South India.
&
The response of hydrological flow and
planation in Indus delta mangroves Sindh,
Pakistan.
Presented by: Uzma Sarfraz

2. AGENDA
• Restoration by means of Hydrological flow changes and
plantation
• Data of rainfall, freshwater and tidal flow.
• Simple statistical and spatial tools
• The hydrological flows in terms of diurnal tidal flow of
seawater and the freshwater flow and water circulation.
• Spatial extent
• The present study aims to analyze the behavior and effects
before, after and ongoing(1930-2014) restoration activities
on the Pichavaram, mangroves, South India.
• Indus Delta mangroves Sindh, Pakistan.

3. MANGROVES FOREST
• Mangrove forests are coastal wetlands
• Groups of trees and shrubs
• Mangroves wetland :Our Green Kidneys
• Which grows in tidal, chiefly tropical, coastal swamps,
having numerous tangled roots that grow above
ground

4. IMPORTANCE OF HYDROLOGICAL FLOWS
• The tidal cycle and the flow inside the
mangroves maximum velocity of about 5
cm/s
• chemical exchanges and exchange of
materials
• Increased sedimentation
• Freshwater discharge leads to the elevation
of terrain level
• Diversity of mangroves
• The nutrient balance of the mangrove
ecosystem due to the salinity, inorganic
nutrients and chlorophyll a is also influenced
by tidal cycles.
• Nutrients upwelling of seawater in monsoon
periods.

5. STUDY AREA
• Mangroves of Pichavaram, South
India
• Forest covers an area of about
1471 ha including mangrove
vegetation, tidal flats, sand dunes
and backwater system.
• The mangrove wetland lies in the
Coleroon, Vellar estuarine
complex, of Cauvery Delta of
South India along the coast of Bay
of Bengal.
• The total catchment area of the
Cauvery is 81,155 km2.

6. DATA COLLECTION METHODS
METHOD FOR AREA TO DERIVE THE DATA OF ASPECTS
Ombrothermic Diagram
Rainfall data
For monsoon
season (July-Sept)
and (Oct-Dec)
rainfall
Parangipellai,
Sirkazhi and
Chidambaram
• The flow of freshwater in the Delta
• Discharge in the sea supporting area for
mangroves species
Proximity analysis
And ArcView 9.3 GIS software
Tidal flow and
freshwater flow
and cover of
mangroves
For freshwater from
Coleroon discharge
and mangroves cover
Of Chidambaram
• Tidal spread and freshwater flow are
the two spatial output derived
• Barrages flow rate
Regression equation (Y= a+ bx)
and Manning equation(Q=A.R.S)
Tidal flow 6 stations (backwater
of mangroves)
• Flow rate
• width of channel
Survey of India TOPO sheet and
satellite images (Landsat)
Tidal flow and
mangroves shrubs
Cauvery delta Prediction of tidal flow and mangroves of
each season and prediction of unrecorded
year
Interpolation by inverse distance
weighted (IDW)
Tidal flow and
species density
Almost all
waterbodies
The wetland inundated by high tides

7. RESULTS
YEAR RESTORATION ACTIVITIES
(1935-2014)
CHANGING IN THE
MANGROVES AREA
RESULT
1930 Clear felling management by
locals
1165 ha Clear felling of mangrove trees exposed mangrove soil,
causing evaporation of soil water, which led to subsidence of
sediment in the clear felled area.
1994 Replanting and clear felling by
government
411 ha Tidal water stagnated in the clear felled area and evaporation
of stagnant tidal water caused increase in soil salinity to a very
high level lethal to any mangrove plants.
1996 Replanting Almost 500 ha Increase of erosion ,wider river sides from 1.2km to 2.6km.
2003 Canal building and replanting
and Cauvery splits into four
streams known as Kollidam Aru,
Kaveri, Vennaru and Puthu Aru
No data
collected
The building of small plants beside river sides.
2011-
14
Small diversion of Vellar river
towards it , replanting ,
remote sensing monitoring.
941 ha Avicenna marina species excessive growth.

8. RAIN FALL
• The climatological (70 years) annual
average rainfall in the study area is 1,310
mm and annual average number of rainy
days was 56.
• The flow, of freshwater in the Cauvery
reaches a peak during the southwest
monsoon season. And excess water in the
north west discharge in the sea supporting
area for mangroves species.
• During the recent three decades, minimum
rainfall recorded was 650 mm.
• Numbers of dry month ranges 3 and 8
during the last five decade.
• The rainfall is high in the month of Nov.
• Smoother annual rainfall (1999-2006),
From 1999 ,rainfall increases (411ha-
461ha)
• Average rainfall shows a normal peak and
fall over 30 years.
• The annual rainfall of the wetland area
from Vellar to Coleroon estuary is almost
same ranging between 1200mm and
1600mm.(1970-1987)
•

9. TIDAL FLOW
• Increase in the width of eustraine system and width of the canal results
in the permits the smooth tidal flow.(1987,1970,1977,2006,2010)
• Increase in the width of the river Coroloon causes the increase in the
flow rate and also increase the mudflats area in the last decade.
• Tidal flats and mudflats increases with the vegetation spread about
660ha-858ha.
• River Coleroon mouth and lagoon flow is higher the near the canal
connecting the Uppanar river with the lagoon.
• The winter flow is higher in Coleroon.
• The width of the Coleroon mouth is gradually increasing from 380m-
900m.(1930-2007)

10. PICHAVARAM MANGROVES

11. Indus Delta Mangroves
• In Pakistan 97% mangroves are found in Indus
delta –Sindh.
• Karachi ,Thatta and Badin district (ketti bunder,
shah bunder, mangho pir, malir, layri, korangi
creek areas)
• The Indus River provides freshwater supplies to
the Indus Delta.
• It is regulated by the Kotri Barrage, which is the
last major hydraulic structure that was built
across Indus River in 1955.
• As the river flows downstream of Kotri
Barrage, it deposits 450 million tones of
suspended deposits discharging 200 km³ of
water.
• The delta receives most of its annual rainfall
during monsoon season.

13. DATA COLLECTION
• The first stage involves
assessment of existing state of
deltaic ecology where the river
downstream of Kotri Barrage was
categorized.
• Environmental management class
(EMC), based on (2007) prototype
model developed at IWMI.
• Landsat imagery (1972-2017) to
extract AOI
• Comparing the shoreline using
the ArcGIS 10.3 (1972-2007)

14. RESULTS

15. Area under cover in the last 28 years 1990-2017
Year Hectares
(ha)
Percentage
(%) of tidal
floodplain
Management Activities (Delta area
:1306700ha)
1990 10341 16.3 No management
1995 63296 12.72 Kottri barrage building year
2000 80267 12.44 No management only Local manipulation
for wood.
2005-9 63296 4.84 Community based Planting and 10 MAF
water released under kotri barrage. Linear,
staggered protective, block type
plantation.
2010 65057 4.98 Fresh water release at Kottri barrage by
WPDA annually increases.
2012-
13
71585 7.22 541,176 mangroves plantation in 2012 and
847,275 mangroves sapling plantation (in 1
day)
2017 81324 12.60 Planting and fresh water release at Kottri
barrage by WPDA

17. Freshwater flow (Precipitation and Temperature relation)

18. •
The MAF of the Indus Delta
Yearly flow in Indus below Kotri to the Delta
Year Total annual
discharge(MAF)
average
1940-1990 34.8 MAF
2000-2010 20 MAF

19. Legal Management status of Indus Delta

20. A Blessing in Disguise…….
• Mangrove forests are rebounding thanks to
climate change
• Increase in temperature
• Floods
• UN Climate Change Conference COP 25 (2 – 13
December 2019 .
• Pakistan is probably one of the only countries in
the world with increasing mangrove cover
• Beside Sindh Govt. mangrove planation (2012-17)
project
• No new dams, canals and barrages building
• But the poor water management of flood
water(freshwater)
• Ideal condition for mangroves spread
• Results in less occurrence and chances of
sea storm and hurricane winds, strong waves
threat in the Sindh coastal areas in the last 5
years

21. COMPARISON
INDUS DELTA MANGROVES,SINDH PAKISTAN MANGROVES OF PICHAVARAM, SOUTH INDIA

22. CONCLUSION
• High freshwater flow for longer period of time creates environment
niches for maximum coverage of mangrove forest and diversity of
mangrove species.
• The forest and water management practices can create favorable
hydrological conditions by manipulating existing tidal flow through
artificial canal system and with the release of timely freshwater.
• The vegetation diversity of the ecosystem and its luxuriance could
be sustained only with favorable hydrological conditions.
• To sustain mangrove wetlands suitable management procedures
need to be evolved and applied to ensure environmental flow, that
is required quantity of freshwater flow into mangrove ecosystem
for required duration.