Assessment of Land and Water Resources of Mine Affected Watershed in India using Remote Sensing and GIS

The present study highlights the application of Geographic information system (GIS) to assess the impact of mining activities by indicating the changes on land and water resources of Olidih watershed in India. Change in land cover was calculated through processed satellite images for four different periods: 1975, 1990, 2000 and 2005. Results reveal that from 1975 to 2005, the mine affected area is increased by 42.61% whereas the forest and barren land decreased by 49.41% and 91.25% respectively. Further, the water quality analysis has been carried out to access the effect of mining on water resources. Water samples were collected in pre-monsoon (PRM) and post-monsoon (POM) seasons and analyzed for various physico-chemical parameters. Water Quality Index (WQI), Sodium Absorption Ratio (SAR), Percent Sodium (%Na) and Total Hardness (TH) were determined on the basis of measured parameters in order to ascertain the suitability of water for domestic, irrigation and industrial uses. The WQI for the study area varies from 23.86 to 166.72 in PRM season and from 22.14 to 146.44 in POM season. In 16.3% and 11.4% of watershed area, water is found ‘unfit for drinking’ during PRM and POM season respectively. The calculated values of SAR and %Na indicate ‘excellent to permissible use’ of water for irrigation uses during both the seasons. High salinity and %Na values at some sites limit use for irrigation purposes. Box plots were plotted to represent seasonal concentration of the major ions which shows increasing trend of Ca, Na, NO₃, and SO₄ during POM.