Assessment and Monitoring of Salinity of Soils After Tsunami in Nagapattinam Area Using Fuzzy Logic-Based Classification.

This article focuses on assessing soil salinity levels and the extent of agricultural land affected by the 2004 Indian Ocean tsunami in Nagapattinam district, Tamil Nadu, India, using remote sensing techniques. High-resolution multispectral satellite images from IKONOS and QuickBird for pre-tsunami (2003), immediate tsunami (2004), and post-tsunami (2006) periods were analyzed through a four-step process: image preprocessing, land region extraction using the Soil-Adjusted Vegetation Index (SAVI), feature extraction and selection of salinity indices, and classification of salinity levels into three classes (highly saline, saline, and non-saline) via fuzzy logic. The study found an increase in highly saline areas from approximately 8.3 hectares in 2004 to 32.6 hectares in 2006, with a corresponding decrease in non-saline land, indicating ongoing soil salinization that adversely impacted agricultural productivity. The research highlights the utility of remote sensing for monitoring soil salinity and recommends continued multi-temporal satellite analysis for managing salinity dynamics in coastal agricultural zones.