IRS LISS
tion and in
to improve
cy of these
The eco-
in Fig.1.
mud
re mapped
ysiographic
gether with
re used to
t mangrove
una 2001,
lity settings
ange due to
etc. In fact
ding is the
especially,
lop proper
f mangrove
oastlines of
¢ mangrove
frared band
ents. Band-
, Red/NIR,
d out using
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Validation
verified on
itered. The
confidence
ities of the
IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002
_—
Source: IRS LISS III data of 29 Jan 2001
ominant mangrove communities zoned using
IRS LISS III data of 2000
3.2 Non-spatial database
Ground data collection was done once every year during 1998-
2001. Data pertaining to ecological parameters for mangrove
habitat was collected by Point Centred Quadrat method
(PCQM). Points to be sampled are. located randomly along a
transect line. From each point four lines are drawn in all the
four directions, resulting in four quarters around the point. The
mean of'the four distances measured has been found
empirically to be the square root of the mean area per tree
(Cottam & Curtis, 1956). From each sample point information
on tidal influence (inundation class of the area as well as at the
time of sampling, i.e., tidal range and number of exposures),
topographic — and strata of the sampling area
(flat/undulating/elevated/ depressions, stand size and condition,
density, number of species, number of individuals of each
species, phenological stage of the individuals (flowering, etc.),
diameter at breast height, height, canopy cover of each species
in the sampling unit, soil type and understory vegetation is
collected.
Ground data collection for coral reef habitat was done by the
Line Transect Method. Nine-line intercept transects of various
lengths (ranging from 160 meter to 4.27 km.) were laid on the
ground stretching from the beach seaward to the edge of the
reef. The geographic locations of different points sampled
along transect were noted using Magellon GPS instrument.
From each sampling unit substrate characteristics, depth of
water, percentage algal, coral cover and seagrass cover, coral
species, size of coral colonies, etc.
4. Conceptual Framework for Generating Models
A conceptual framework was designed and models generated
for environmental appraisal of the habitat, for defining
vulnerability index and for management zoning of the vital
habitats.
For appraising the environment of the habitats, the change
detection studies were carried out and incorporated into the
database. Based on the ecological condition (obtained from
detecting changes that have occurred in the area, other
secondary parameters like coral diversity, percentage cover,
405
mangrove species, etc.,) the habitats were designated as good,
moderate and degraded habitat.
Reef slope, reef crest, algal ridge, deeper zone, reef flat with no
change, no change from 1989-2001, reef flat on seaward side
having more than 70% of the representative coral diversity and
percentage cover of the region, faunal diversity, reef flat with
seagrass, reef flat with algae/seaweeds, portions of reef flat
(seaward) which has remained unchanged, all creeks falling in
this zone and all coral heads are to be designated as Good
Habitat. Other reef flat portions (not falling in Good habitat),
portions of reef flat, which has improvement by way of
decrease in mud deposition extent, sand (vegetated and
unvegetated), beach, algae on mud on reef and all creeks falling
in this zone are moderate habitats. Mud depositions on reef
(thick/thin), increase in mud deposition areas, portions of reef
flat on landward side where vegetation (matty and filamentous
algae) has increased, etc, show the degraded condition of the
coral reef habitats.
Similarly mangroves with highest diversity, no change from
1975 to 2001, change from sparse to dense category of
mangroves, density — 70-8096 or more, other floral diversity
(algae, marsh) — more than two species, faunal diversity of
birds, reptiles, fishes and other fauna relatively rich, good
network of creeks, all inter-tidal mudflats falling within the
mangroves and all sub-tidal mudflats make up the Good habitat
of mangroves. Mangrove of 40-7096 density, minimum twp
species diversity, mangroves which have degraded and become
sparse, barren areas which have converted to dense mangroves
because of plantation, ^ dense-sparse/degraded/defoliated
mangroves which has changed to dense (by way of regeneration
or improvement in growth), all inter-tidal mudflat within the
mangroves, all transitional mangroves, mud with vegetation,
marsh vegetation, beach and all barren intertidal mudflat on the
seaward side. High tidal mudflat, dense to barren (defoliated)
mangroves, sparse to degraded mangroves, degraded
mangroves (less than 10% mangroves), barren to sparse
mangroves and saline blanks are the degraded mangrove
habitats.
Habitats at maximum risk or vulnerable habitats are essentially
those areas, which are currently in good condition (or good
habitat) but are under danger of degradation. Therefore,
nearness to habitation, population pressure (total population),
nearness to the industries, Single Buoy Moorings, port/jetty,
pipeline, accessibility/approachability, nearness to an already
impacted area, increase/decrease in extent of mud deposition
are the criteria for assessing vulnerability. The habitat nearest to
the above is the habitat at maximum risk and at a distance from
the above is at least risk. From the habitats the species at
maximum risk can also be assessed. The critically endangered
species shows 80% decline in its population in last 10 yrs with
the number of mature individuals showing more decline and
occupancy area reduced to 10%. If the decline in population is
50% in last 10 years with continuous decline in mature
individuals the species is endangered. The occupancy of such
species may have reduced to 50% in last ten years. Vulnerable
species category is assigned to those species having 20%
decline in population in last 10 years, area of occupancy
reduced to 50%, and number of mature individuals reduced to
50%.
For management purposes it is suggested that the habitats be
divided into preservation, conservation zones with some areas
also demarcated for development. Preservation (Core Zone)
