Investigation of heavy-mineral deposits using multispectral satellite data

Abstract

Mineral deposit mapping is essential for sustainable and eco-friendly exploitation of natural resources. The south Tamil Nadu coast of India is rich in minerals. Currently the beach sands are extracted for export entirely in raw form without any value addition. Due to unsustainable sand mining, there are negative environment impacts, which lead to various coastal hazards such as erosion, salinization and sea-water intrusion. In order to initiate the focus on mapping of mineral deposits along this area, standardized hyperspectral analysis has been carried out using Landsat satellite data and Environment for Visualising Images (ENVI) software. The selected endmembers are identified by comparing the spectral signatures with predefined spectral plots from the United States Geological Survey (USGS) spectral library. Finally the endmembers are mapped with ENVI's spectral angle mapper (SAM). The minerals which show significant variation in reflectance at different spectral bands can be effectively mapped by using multispectral data. Ground verifications performed to assess the accuracy of classification were mostly in agreement with the obtained results. This study has opened up new areas for inland heavy mineral exploitation and leads to eco-friendly exploitation of natural resources along the study area. It also illustrates the high potential of multispectral satellite data for exploration and mapping of mineral resources.