Satellite-Imagery Intelligence : An Advanced Observation Strategy For Mining Industry

 

A sound understanding of geography is needed in every phase of a mining venture development. Starting with exploration and resource mapping, the extraction of regional and local fracture patterns and the identification of lithological unites, to mineral analysis, to finding an ideal location for the mining facility, including disaster management and environmental impact assessment of all elements. Earth observation information, from commercially available optical remote sensing systems, is regarded as a powerful tool for all phases within the mining industry. Geospatial products, in particular, play an important role because of their unique ability to provide highly accurate and detailed 3D geospatial information and solutions that increase the efficiency of reconnaissance mapping, exploration, logistical planning, production operations and mine closure or reclamation. 

 

Environmental pollution due to mine exploitation is a complicated change which cannot be categorized by one single indicator. Hence, effective monitoring of mineral resources exploration and its collateral damage to environment thereof is the primary goal to achieve sustainable development of mine enterprises. Monitoring of geological environment of mine is crucial to improve mine environment and mitigating damage caused by exploitation. With continuous development of satellite remote sensing technology, spatial resolution and spectral resolution of commercial satellite data, it has become a dynamic tool in monitoring mining activities and mine ecological environment.

 

 

 

Development of satellite remote sensing has made it possible for monitoring of mine ecological environment based on high resolution satellite remote sensing image to meet actual demand with adequate accuracy. Various ecological environment factors can be fully reflected on the remote sensing image by meter-scale spatial resolution, digital image processing is performed based on spectral feature and imaging feature of various ecological environment factors, pollution investigation and analysis of environmental elements are conducted on the basis of information extraction and classification to acquire pollution and damage situation of each environmental element as well as overall situation of regional ecological environment, and to analyze major pollution and its distribution, dispersal path of pollution and so on in combination with information affected by remote sensing. Synoptic, real-time and robust information source of mine ecological environment can be acquired through processing of remote sensing image, to support decision-making on environmental control and to evaluate control effect. With regard to restoration and reclamation of mine, satellite remote sensing also play an increasingly important role. 

 

 

Remote sensing data enables the identification, delineating, and monitoring of pollution sources and affected areas, including derelict land, and changes in surface land use and to water bodies.   Using high resolution satellite remote sensing data and state of the art GIS techniques with parallel development of a fully integrated geospatial database system allow monitoring at appropriate spatial scales and  therefore, such data can be used for long-term environmental management and monitoring of reclamation and rehabilitation of mining areas. 

 

Acid mine drainage into surrounding areas is recognized as a major pollution threat for open cut base metal mine workings as well as for coal and lignite mines. Airborne and satellite based hyperspectral sensors can detect these mineral zones due to their distinctive spectral signatures.

 

 

 

The ore mining areas contain large number of tailing ponds to store the byproducts left over from mining. These pose a great threat to regional safety and the environment and so to monitor them, their spatial distribution information is important. High resolution satellite imagery can be used to extract such information based on both spectral and texture characteristics. Different remote sensing indices (NDVI, NDWI) can be used to generate thematic information of the mining area.

 

 

So mine pollution mainly include water pollution, soil pollution and air pollution, among which, water pollution can be identified directly by remote sensing technology while air pollution and soil pollution are hard to be identified directly by remote sensing technology, due to which it is important to identify vegetation pollution which  reflect air pollution and soil pollution indirectly. It comprises of 3 main methods: Image Compounding method, Vegetation Index method and Vegetation Greenness method.

 

Mine geological disaster or geo-hazard means disaster generated by mining and production activities of human which destroys geological environment, endangers safety of life and property and brings about heavy economic losses. Main geological disasters include landslide, mud-rock flow, ground fissure surface subsidence or even dam collapse of tailings pond. 

 

Satellite Imagery is a reliable tool for frequent monitoring of mine subsidence and land deformation. This information is necessary for raising warnings on possible infrastructure instability and collapses. It is possible to detect a small ground deformation over a large area at sub centimeter accuracy. The fundamental behind this is the difference of reflection energy received back at the satellite sensor from the same surface feature due to topographic changes of gradient and slope aspect by which fluctuant topography change can be identified. Change of micro relief can be used to infer location of ground fissure, which can be taken as basis to delineate and calculate area of subsidence area.

 

 

Remote sensing is a comparatively mature monitoring method which is capable of reflecting various situations at the exploiting area in a more intuitive manner. High resolution satellite imagery is effective to monitor mining without regulations or plans during primary stage. Professionals can obtain information of status of solid wastes piles, exploitation situation of mine, certain scale ground fissure, mine building and traffic and so on based on up-to-date satellite imagery. It allows volumetric and change detection analysis. Digital Elevation data can be used for hydrological studies, utilities management and placement, natural hazard assessment including flood susceptibility and emergency escape access, environmental impact studies, property access, alluvial flow directions and slope and delineation of rock types based on outcrop. In addition, vegetation index can be used to monitor mine expansion. Vegetation index is a simple and effective measure parameter used in remote sensing to represent surface vegetation coverage and growth status and is widely used in qualitative and quantitative assessment of vegetation coverage and growth vitality for mine reclamation monitoring. The differences between chlorophyll, moisture content, cell structure and other vegetation leaf features also can measure vegetation coverage and contribute towards successful mine restoration/reclamation planning and execution.

 

 

 

So in today’s time, high resolution satellite imagery has become an indispensable means to monitor the varied facets of the mine environment. Satellite-derived intelligence can help mining companies, specialists and consultants make smarter geological, geotechnical and safety-related decisions throughout the mining lifecycle. Synoptic, clarity, accurate and precise nature of optical imagery promises an improves situational awareness in and around the mine environment and help precisely map and monitor various parameters associated with mining activities such as the stability of mine caverns, pits, tailings, infrastructure and geo-hazards etc. Also, this satellite based approach clearly identifies subtle changes in vegetation composition and health across re-vegetated surfaces and proves a valuable addition for mine rehabilitation management.