Aquatic Pollution and Coastal Management

Unit 14 : Coastal zone management and information system

14.7.1. Coastal geomorphology and habitat
In the present day scenario, in comparison to the Survey of India (SOI) toposheets, photo-mosaics and/or up-to-date geocoded satellite data products of similar scale (i.e 1: 50,000) provide more quantifiable information about the morphology, morpho-arrangement, morpho-genesis and constituent material of the different landform unit as well as existing land cover/landuse pattern at a glance to the users.

In coastal zone/estuarine areas the common landform/mapping units are,

• a. Marine cliffs and notch zones’
• b. Marine wave cut platforms,
• c. Beaches, beach ridges/runnels, spits and tombolo bars,
• d. Coastal dunes (active, inactive or dormant),
• e. Vegetated/Non-vegetated tidal sandy/mud flats,
• f. Marine terraces/flood plains,
• g. Coral reefs,/reefs flats/reefs caps/uplifted reefs,
• h. Ramparts and cays,
• i. Lagoons,
• j. Fluvio-deltaic flats

In response to the repetitive coverage, multi-seasonal or time critical satellite imagery could be used to monitor the spatial variation of the aforesaid landform units/mapping units, the fluctuation of the inundated areas of the tidal flats or the natural of the tidal creeks through seasons. Change detection in the mangrove forest boundary or deforested patches could also easily identified in the RS data products as the broad leaf, healthy mangroves have their very characteristic reflection pattern. It may be mentioned here that the range of scales for surveying and /or resolution of the RS data are also to be subject specific i.e varies with the nature of the project undertaken, for instance, monitoring of the shore line changes or identification of aquiculture farms requires more resolution than those needed in study of general landform features or natural hazard zonation. In view of that, a ‘zooming – in’ or multiphase approach is suggested starting form use of geocoded imagery/aerial photographs (on scale 1: 50,000) to air photos or digitally enhanced imagery 9 o scale 1: 25,000/20,000/10,000) with subsequent field checks.