The combination of GIS and statistics makes it possible to know, from where the material has comes and to where the material has gone, especially in land locked countries. This study quantitatively and spatially discusses the relationship between anthropogenic disturbance and material flows taking the Germany as a case study country.
We employ geographic information systems (GIS) with digital elevation model (DEM) and land cover datasets, to measure anthropogenic disturbance of soil and earth at extraction sites, which accounts not only for the material extracted for usage, but also its related unused extraction. The unused materials such as plant, overburden and waste rocks by mining, construction and farming are known as hidden flows (HF). Especially anthropogenic disturbances caused by material extraction is destructive and irreversible effect of the natural environment. From the point of the material transfer between the eco-sphere to socio-economical sphere, anthropogenic disturbance is known as the starting point of material flow hence only few studies have considered its impacts.
In parallel, backfill and landfill sites are also focused as one of a huge anthropogenic disturbance, and the same methodology was applied in order to measure mass of filled materials. Worthy of special mention is that in order to do land recycling for abandoned and post mining site, the most of unused materials (overburden and waste rocks) are used as backfilling material, but the total mass of filled materials are not qualitatively and spatially discussed with material flows.
GIS based calculation shows the total material extraction is 15.3 billion ton, and the total material fill (landfill and backfill) is 7.76 billion ton. Statistics based calculation shows the total material extraction is 9.32 billion ton, and the total material fill is 1.77 billion ton. The gap between results of GIS and Statistics is 5.98 billion ton at extraction sites, and 5.99 billion ton at filling sites. The gap (5.98-5.99 billion ton) would be unused materials (HF) that only the GIS based calculation can be accounted.
On the other hand, according to statistics, 20.1 billion ton of HF are generated behind the 9.32 billion ton of material extraction. Statistically the total material extraction achieves 29.3 billion ton. Compared to the total material extraction by statistics (29.3 billion ton) and GIS (15.3 billion ton) is 14.1 billion ton. The gap (14.1 billion ton) would be unused materials that are used as backfilling materials. The DEMs we used are taken in 2000 and 2010, therefore the mass of annual backfilled materials cannot be calculated by GIS based calculation. In this study we accounted 5.98-5.99 billion ton of unused materials, while 14.1 billion ton of unused materials which may be used for backfill of material extraction site are estimated.
Analysis of anthropogenic disturbance with spatial information can effectively contribute to observe, analyze, and quantify this kind of environmental impacts, and can thus provide policy makers useful and practical information to make decisions regarding sustainable resource usage.
