Illegal mining and its control has always been troublesome for India. Mining activity is illegal if it is done without licenses or outside the permitted leased areas. Even extraction above the permissible limit is illegal.
Though hazards from illegal mining are similar to normal mining, it intensifies the hazard condition without any gain. It leads to rapid environmental degradation, illegal forest cutting, ecological changes, severe health hazards, corruption, etc. So, monitoring illegal mining becomes very crucial to mitigate and stop adverse impacts, environmental and economic losses.
Indian Government has taken steps to curb illegal mining. The Indian Bureau of Mines (IBM) has collaborated with the Indian Space Research Organization (ISRO), Department of Space for monitoring mining activities through satellite based technology. A Memorandum of Understanding (MoU) has been signed between IBM and the National Remote Sensing Centre (NRSC) in 2016 that should lead to sustainable development and responsible use of natural resources.
Satellite based Remote Sensing is one of the best ways to monitor mining activities as it can provide near real time monitoring of mining areas. ISRO has carried out a pilot project to monitor the deviations of mining activities i.e. mining beyond permitted lease areas in various open cast mines in India over selected groups of mines in Tandur and Bellary under the IBM. This project by ISRO has demonstrated the feasibility of using high resolution satellite imageries for monitoring the mining activities i.e. areal as well as volumetric changes over a period of time.
Different methodologies have been adopted by ISRO to find out the areal and volumetric changes. Areal change analysis of mines has been done by fused product generated from high resolution Multi-temporal satellite imageries of Cartosat -1 and LISS IV whereas volumetric change is estimated by differencing the Digital Elevation Models (DEM) generated from multi-temporal satellite images of Cartosat-1. The figure given below depicts the spatial changes in one of the cement mines in Tandur through Cartosat-1 satellite images taken in the years 2007, 2011 and 2015.
Fig: Spatial changes in cement mine, Tandur Source: ISRO
Overburden and cut volume of mining area for year 2007-11 and 2007-15 has been estimated and is depicted in the given map. These images clearly show how mining area has increased over the years.
Volumetric Change estimation in cement mine, Tandur, Source: ISRO
There is no doubt that the space technology used by ISRO has shown the potential for monitoring mines but has also given benefits of checking illegal mining activities and cut time consuming ground surveys.
There is no doubt that the space technology used by ISRO has shown the potential for monitoring mines but has also given benefits of checking illegal mining activities and cut time consuming ground surveys. The Supreme Court on August 3, 2017 gave a directive to companies in Odisha involved in illegal mining to make a payment of INR 17,576 crore in total as compensation, which represents 100 per cent of mineral extracted by them without environmental clearances (ToI, 2017).