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545 Application of Remote Sensing and GIS

regeneration/ regrowth of forest area and tracing major changes in land
cover.
Remote sensing data derived from different satellite such as
Landsat MSS data can provide us information about the areal extent,
conditions and boundary of coastal wetlands. Further, multidated
satellite data can be used effectively to find out the changes in the aereal
extent of mangroves. Sequential nature of IRS data provide opportunity
to monitor changes in the landuse activities in the mangroves. IRS has
been quite extensively used for Mangrove landuse pattern both the
visual as well as the digital analysis of IRS data provide useful
information.

Data acquired by both passive and active remote sensing systems
can be used in the study of mangroves. The research involves two main
steps. In the first step, a broad classification of the general land cover,
including mangroves is made (Figure1). This indicates the best approach
to dealing with the various types of imagery in order to detect the
mangrove deforestation. The second step concentrates on the specific
problem of detecting changes in the mangrove areas (Figure2). It
examines different approaches for monitoring the nature of the changes
in order to produce maps showing the current and former conditions in
an area. SAR data, which is independent of cloud, cover and weather
interference can be used for mapping mangrove and estimation of
mangrove biomass.
One of the sub tasks of Land Ocean Interactions in the Coastal
Zone (LOICZ) of IGBP project is to develop a methodology for
mangrove zonation, succession and regeneration (IGBP, 1994). The
important tasks for the study of mangroves are mapping and change
detection, identification of species/ plant communities and biomass
estimation. To prepare a management plan for mangroves, a
comprehensive database should be available, including the information
on distribution and extent of mangrove areas and species composition.
As a first step towards this, the Space Applications Centre has carried
out national level wetlands mapping to prepare shoreline change maps
and wetland maps on 1: 250,000 scale (SAC, 1992). This work presented
the status of wetlands, primarily the level‐I and level‐II categories and
the total area of mangroves has been estimated to be about 4000 sq. km.
Although the methodology for visual interpretation of satellite
data for vegetation/ land cover classification and mapping has been
standardized and made operational in India, the potential of high
resolution data such as IRS LISS‐II and LISS‐III for extracting vegetation‐