Spatio-Temporal Analysis of Shoreline Change Along the Machilipatnam Coast Using Landsat Imagery and QGIS

Abstract

Shoreline analysis is an important aspect of coastal studies, as coastlines are continuously influenced by natural processes such as waves, tides, currents, and human activities. Monitoring these changes is essential for effective coastal management, environmental protection and sustainable development. This research work focuses on the analysis of shoreline characteristics along the Machilipatnam coast in Krishna District, Andhra Pradesh, using geospatial techniques.  Landsat ETM + satellite imagery for the period 2018 to 2022 was used as the primary data source. The satellite data provides multispectral information with moderate spatial resolution, making it suitable for coastal analysis. The images were processed using QGIS software, where band combination and colour composite techniques were applied to enhance the visual distinction between land and water features. A layer stack approach was used to organize raster data for better interpretation. The shoreline was identified based on textural variations and digitized as a vector line layer. Additionally, the land and water regions were digitized as polygon layers to enable spatial analysis. Various GIS tools were used to calculate shoreline length and area measurements, allowing for systematic comparison across multiple years. This study demonstrates the effectiveness of integrating remote sensing and GIS techniques for shoreline mapping and analysis.