358
land erosion and hypersalinity parameters are liable to mangrove degradations; and
finally, fishery development, sediment deposition and land erosion parameters are
sequentially responsible for mangrove degradations in Henry’s Island.
Keywords Mangrove degradation checklist (MDC) • Sundarban • Biological indicator • Geospatial techniques • Factor analysis (PCA) • Vulnerability • Mangrove
restoration
11.1 Introduction
The upper intertidal and supra-tidal zones of the Sundarban contain mangroves with
traditional impenetrable jungles ruled by the natural forest guard as the Royal
Bengal Tiger. Sediment accretion rates, surface stability of younger alluviums,
unique ecosystem, natural bio-shield, and many other physico-chemical functions
are controlled directly by the growth and distribution of mangroves in such tropical
hot and humid environment. Presently it is proved that the nutrient recycling and
carbon exchange between terrestrial and marine environments are strongly supported by dense growth of mangrove. They are important habitats for fish and crustaceans on which humans are dependent (Woodroffe et al. 2013). Mangroves are
distributed in a sea word zone, land word zone and in a transitional zone dominated
by several salt tolerant species. In Sundarban coast, brackish water community of
Nypa fruticans and Heritiera littoralis often dominate the transition to inland vegetation with peaty swamp forest; but unfortunately, both the vegetation species are
degraded due to salinity in the southwestern parts of the region (Fig. 11.1).
Mangroves can adapt themselves against sea-level rise by increased rate of siltation or sediment accretion and by inland migration through estuaries and other
associated wetlands (Thom 1982). However, the present study shows that mangroves of the Sundarban are affected by degradations as estimated through the experiences of repeated observations over a time and space using photographic
documentations and remote sensing techniques.
Several factors and sub factors are estimated as diversity of mangrove degradation (over uses by humans, development of fisheries, hypersalinity, sediment movement, storminess or storm effects, shoreline erosion, and regeneration problems) in
the Sundarban coast predominantly influenced by hydrodynamic and morphodynamic changes at present. The cyclone ‘Sider’ in November, 2007 and cyclone
‘Aila’ in May, 2009 resulted in drastic changes in mangrove communities of the
Sundarban, and increased frequency of storminess of the Bay of Bengal may result
more devastation of mangroves on the coast in the near future.
The Sundarban without having mangrove buffers will be periodically affected by
salt water floodings, rapid rate of shoreline erosion, non-availability of nutrients,
costlier and unsustainable protection structures and increased human vulnerabilities
A.K. Paul et al.
land erosion and hypersalinity parameters are liable to mangrove degradations; and
finally, fishery development, sediment deposition and land erosion parameters are
sequentially responsible for mangrove degradations in Henry’s Island.
Keywords Mangrove degradation checklist (MDC) • Sundarban • Biological indicator • Geospatial techniques • Factor analysis (PCA) • Vulnerability • Mangrove
restoration
11.1 Introduction
The upper intertidal and supra-tidal zones of the Sundarban contain mangroves with
traditional impenetrable jungles ruled by the natural forest guard as the Royal
Bengal Tiger. Sediment accretion rates, surface stability of younger alluviums,
unique ecosystem, natural bio-shield, and many other physico-chemical functions
are controlled directly by the growth and distribution of mangroves in such tropical
hot and humid environment. Presently it is proved that the nutrient recycling and
carbon exchange between terrestrial and marine environments are strongly supported by dense growth of mangrove. They are important habitats for fish and crustaceans on which humans are dependent (Woodroffe et al. 2013). Mangroves are
distributed in a sea word zone, land word zone and in a transitional zone dominated
by several salt tolerant species. In Sundarban coast, brackish water community of
Nypa fruticans and Heritiera littoralis often dominate the transition to inland vegetation with peaty swamp forest; but unfortunately, both the vegetation species are
degraded due to salinity in the southwestern parts of the region (Fig. 11.1).
Mangroves can adapt themselves against sea-level rise by increased rate of siltation or sediment accretion and by inland migration through estuaries and other
associated wetlands (Thom 1982). However, the present study shows that mangroves of the Sundarban are affected by degradations as estimated through the experiences of repeated observations over a time and space using photographic
documentations and remote sensing techniques.
Several factors and sub factors are estimated as diversity of mangrove degradation (over uses by humans, development of fisheries, hypersalinity, sediment movement, storminess or storm effects, shoreline erosion, and regeneration problems) in
the Sundarban coast predominantly influenced by hydrodynamic and morphodynamic changes at present. The cyclone ‘Sider’ in November, 2007 and cyclone
‘Aila’ in May, 2009 resulted in drastic changes in mangrove communities of the
Sundarban, and increased frequency of storminess of the Bay of Bengal may result
more devastation of mangroves on the coast in the near future.
The Sundarban without having mangrove buffers will be periodically affected by
salt water floodings, rapid rate of shoreline erosion, non-availability of nutrients,
costlier and unsustainable protection structures and increased human vulnerabilities
A.K. Paul et al.