1. Lecture On Generation of Mangrove Maps
Training Course on
‘Marine GIS for Operational Oceanography’
January 18-22, 2016
R S Mahendra
International Training Centre for operational Oceanography(ITCO),
INCOIS, Hyderabad, India

2. Importance of mangrove
Mangroves are a crossroad where oceans, freshwater, and land realms meet. They are among the most productive and complex ecosystems on the planet, growing under environmental conditions that would kill ordinary plants very quickly.
They are the buffer zone between the land and the sea.
Mangroves protect the soil from erosion.
They play an invaluable role as a nature’s shield against cyclones, ecological disasters and as protector of shorelines.
They are a breeding and nursery grounds for a variety of marine animals.

3. Biological Diversity
Mangroves provide food, nesting and nursery areas for many coastal and marine organisms which include fish species, amphibian species, mammal species and bird species.
Removal the mangroves and many of these species might be driven to extinction, invariably affecting us as source of food and water and many other ways

4. Environmental Protection
Mangroves protect the coastline by acting as "wave breaks”.
They stabilize coastlines and serve as natural barriers/protectors against huge storms, preserving coastlines.
They act as wind breaks which reduce the force of winds, lowering the chances of property getting destroyed in wind storms.
It also provides protection from tsunami waves

5. Mangrove Distribution
Source: commons.wikimedia.org
Found in coastal areas all over the tropics
Primarily in brackish water
salty and fresh mix
Cover approximately 22 million hectares in tropical and subtropical coasts
Within the 20oC isocline

6. Mangrove Distribution in India

7. Mangrove Species Zonation
Bruguiera gymnorrhiza
Ceriops
australis
Rhizophora
stylosa
Avicennia marina
All increase toward shore
Sea
Land
Salinity
Inundation
Decreasing Soil Stability
Sedimentation Rate
James A. Danoff-Burg, Columbia University,

8. Why to map mangroves?
Mangroves help in production of detritus, organic matter, recycling of nutrients, and thus enrich coastal waters and support life.
Routine monitoring is essential.
Principal component and band ratio techniques are most suited for mangrove discrimination.
Mangrove zonations essential for bio-diversity assessment and preparing management plans.

9. Mangrove Mapping Methods
Field surveys: transect, Grid, random
Remote sensing: Visual and Digital
Aerial survey: medium altitude, low altitude

10. Scientific Base for Mapping
Zhang and Tian (2013)
Plate depicting the ETM spectral window and its transmission percentage (above). The individual bands (below).

11. Case studies

12. Spatio-temporal changes in the Mangrove environs due to 2004 Sumatra Eq.
Methods
Case study 1

13. Change Assessment
Total ~49.24 km2 areas of mangroves were degraded during in the Andaman coast.

14. Identification of hot spots and well managed areas of Pichavaram Mangrove
Case study 1
Table 2 Data set used for the study
Satellite
Sensor
Spatial Resolution
Wavelength
(µm)
Date of Acquisition
Landsat TM
30 m
29/01/1991
28/10/2000
Resurcesat-1
LISS-IV
5.8 m
22/07/2006
Satellite Data used
Study area
Kumar et al 2012

15. Case Study: Pichavaram Mangroves
Mangrove Mapping and Monitoring
Case Study: Pichavaram Mangroves
Srinivasa Kumar, T., Mahendra, R. S., Nayak, S., Radhakrishnan, K. R. and Sahu, K. C. (2011) Identification of hot spots and well managed areas of Pichavaram mangrove using Landsat TM and Resourcesat – 1 LISS IV: An example of coastal resource conservation along Tamil Nadu Coast, India. Journal of Costal Conservation, DOI: /s , available online.
Kumar et al 2012

16. Spatio-temporal variation of Pichavaram Mangroves
Mangrove Class
Area in km2
1991
2000
2006
Dense Mangrove
2.76
3.17
5.00
Open Mangrove
1.80
3.38
2.06
Total area
4.56
6.55
7.06
Kumar et al 2012

17. Area of Mangrove classes
Kumar et al 2012

18. Spatio-temporal changes in the coral environs due to 2004 Sumatra Eq.
Tectonic disturbances
Total Coral Area
Exposed Reefs
Tobita, et al, 2005
Total area of exposed category recorded ~113 km2 from Andaman Islands

19. Zonation of Mangroves - Sunderbans
Avicennia dense
Avicennia marina dense
Avicennia sparse
Aegialitis-Ceriops-Excoecaria D
Phoenix dense
Marsh vegetation
Grass (Dhanchi)
Saline blanks
Inter-tidal mudflat
Sand
Creek
Lothian
Dhanchi

20. Mangrove of Koringa Creek Kakinada
Net reduction of mangrove area 8.8 km2
Reddy and Roy (2008)

21. Conclusions of case studies
The Remote Sensing and GIS techniques used in concurrence with the usage of satellite data gives fairly better results in understanding the spatio-temporal changes in mangroves along the coastal zones.
In light of all these facts and analyses, it can be concluded that there is a strong need to make necessary coastal management programmes and implement them in potential risk zones.

22. Thank You