National Assessment for Shoreline Changes
This shoreline change assessment for the coast of India represents long-term shoreline change for a period of 38 years from 1972-2010. Shoreline change evaluations are based on comparing four to five historical shorelines, archived from satellite imageries for the above time period, with recent shoreline derived from LISS III images and limited field surveys. The primary goal of this study is to develop standardized methods for mapping and analyzing shoreline movement so that internally consistent updates can periodically be made to record shoreline erosion and accretion. Appropriate use of remote sensing technology coupled with limited DGPS surveys was integrated in GIS platform to obtain historical shoreline information.
For the coast of India, base maps were prepared on 1:50,000 scale using the toposheet of the Survey of India and onscreen digitization of coastline using multi-date satellite images on 1:50,000 scale and stored as four different layers in GIS environment for the period between 1972 and 2010. The multi-date shorelines served as input into the USGS digital shoreline analysis model to cast various transects along the coastline. A distance of 300m (in some cases 500m) intervals were assigned to calculate the erosion/ accretion statistics in ArcGIS 9.3 software. The erosion/accretion rates are derived from "statistical analysis" of multi-date shorelines using the Linear Regression Rate (LRR) of the USGS Digital Shoreline Analysis System. In the future, it is intended to use High Resolution Satellite Imagery along with DEM to derive precise shoreline changes.
In the present study a method involving remote sensing technology coupled with limited DGPS surveys is being used to integrate in GIS to collect historical shoreline information.
From the Survey of India Toposheets base map was prepared and the onscreen digitization of coastline was carried out and kept as one layer in GIS environment Common protocols were adopted for digital analysis of the satellite images
- Tamil Nadu
- Andhra Pradesh
- West Bengal