Estimation of long and short term shoreline changes along Andhra Pradesh coast using Remote Sensing and GIS techniques

Identifying shoreline changes and its variability is a fundamental task for various coastal studies undertaken by coastal scientists, engineers and coastal managers. ICMAM-PD has implemented a national project for monitoring the shoreline changes for entire Indian coast using satellite imageries to maintain a long-term database in GIS environment. In this paper an attempt has been made to implement a "shoreline proxy" for monitoring the shoreline changes along Andhra Pradesh coast for last 22 years (1990-2012). Multi-resolution satellite data such as Landsat TM, Landsat ETM+, IRS-P5 (Cartosat-1) and IRS-P6 (LISS-III & LISS-IV) were used to assess the short and long-term shoreline changes. The Standard Operating Protocols were followed for image rectification, shoreline extraction and the map accuracy as per NNRMS standard. The changes were classified as stable, erosion (low, medium and high) and accretion (low, medium and high). 974 km long Andhra coast was divided into 89 segments identical to Survey of India toposheets of 1: 25000 scale. The analysis revealed that 275 km long shoreline was under erosion, 417 km has shown accretion and 153 km coastline is under stable condition. Region like Korakupalaiyam, Pallikuppam, Toppalappalaiyam, Virrasettitannippandal, Vatturupallipalem (above the Upputeru River), Ramulapatisangam, Binginipalle, Rayaduruvu, Peddaboyanapalem, Ullapalem, Uppada etc are identified as high erosion prone areas. However, the regions like Bangarapalem, Yerraipetta, Pedhatheenarla, Kothachodupallipetta, Konapapapetta, and northern Kakinada were seen with low to moderate erosion. Pattapupalem, Pallepalem, Kesavapalem, Gundamala regions were noticed with moderate accretion. Southern coast i.e. Nellore to Sriharikotta is mostly stable or accreting nature. Further in northern parts, Ichchapuram to Beemunipatanam coast does not depict any significant change as it is covered with sand dunes and sandy beach. (C) 2015 The Authors. Published by Elsevier Ltd.