Geospatial Assessment
of Soil Salinity in an Urban Coastal Environment: A Case Study of Chennai Metropolitan
Region, Southern India
Sundaramoorthy Sridhar, Moorthy Prabhakaran, Abdul Rahim Ahamed Ibrahim and Chokkalingam
Lakshumanan
Disaster Advances; Vol. 18(12); 59-70;
doi: https://doi.org/10.25303/1812da059070; (2025)
Abstract
Soil salinization is a growing environmental issue in coastal urban regions, impacting
land productivity, vegetation health and infrastructure. This study provides a geospatial
assessment of soil salinity across the Chennai Metropolitan Region using multi-temporal
Landsat 8 OLI imagery and spectral salinity indices. Thirteen indices including
SI, SI1–SI4, SR, RSI, MSR, NDSI, NDVI, GNDVI, SAVI, DVI, VSSI and EVI were used
to capture surface reflectance and vegetation degradation. An integrated machine
learning-based overlay analysis using Random Forest (RF) classified salinity into
five categories: very low, low, moderate, high and very high. Results indicate that
the northern coastal belt of Chennai, especially areas near the Bay of Bengal, falls
under high to very high salinity due to tidal intrusion, urbanization and inadequate
drainage. Inland zones like Madhavaram, Ambattur, Alandur, Guindy, Velachery and
Sholinganallur showed low to moderate salinity levels. Landuse Land Cover (LULC)
data for 2025 was incorporated to examine spatial correlations between salinity
and urban expansion.
This study highlights the effectiveness of combining spectral indices with machine
learning to identify salinity hotspots and support informed urban planning and sustainable
land management in vulnerable coastal megacities.
