Slope aspect affects geomorphic dynamics of coal mining spoil heaps in Belgium

Abstract

After the abandonment of coal mining in Belgium in the 1960s-1980s, many coal tips have been left to themselves. Increasingly, these coal tips are regarded as socio-cultural heritage and protected for their environmental value. This research analyses the spatial distribution of the main geomorphic processes (sheet and rill erosion, landsliding, rock fragment movement and root throw) occurring on coal tips in Belgium, through mapping of the processes and their causal factors. Five spoil heaps spread over the major coal basins were studied in detail. The spoil heaps were subdivided in homogeneous land units, especially with regard to slope gradient, vegetation cover and slope aspect. Qualitative and quantitative observations were done on processes and potential causal factors. Regressions showed that generally, the expression of slope processes on the studied coal tips is (1) strongly dependent on westerly aspect of the slopes, (2) independent of slope gradient (which presents a narrow range), (3) impeded by grass cover, and (4) not fully predictable due to variability in type and age of dumped mine spoil.

Aspect-induced differences in soil erosion intensity in a gullied hilly region on the Chinese Loess Plateau

“…Different combinations of the factors mentioned above probably lead to different soil erosion intensities and geomorphic evolutions. For example, in Belgium spoil heaps there is a strong negative correlation between landsliding and tree cover (Nyssen and Vermeersch 2010). However, this is not the case in our present study, implying that other factors would not be neglected when geographic dynamics are studied in respect of slope aspects.…”

“…Due to higher water content on the shady slopes, grass/ shrub vegetation occupies the sunny slopes, while forests are located mainly on the shady slopes. Nyssen and Vermeersch (2010) found correlations between slope aspect and tree cover, with highest tree cover and lower rill erosion on the shady slopes. The higher vegetation coverage leads to higher anti-erosion capacity and lower E i values for the shady slopes than the sunny slope counterparts.…”

13.6 Impacts of Mining on Geomorphic Systems

“…The remains of a Roman alluvial gold mine at Las Médulas in Spain are so spectacular as to justify the site being designated UNESCO World Heritage status. In Belgium, the spoil heaps from coal mining are considered important landforms reflecting the sociocultural heritage of an earlier industrial era, and are protected for their environmental value (Nyssen and Vermeersch, 2010 The extent and intensity of mining grew substantially during the industrial revolution. It has been estimated that the use of mineral resources increased 10-fold from 1750 to 1900 and another 13-fold from 1900 to 1990 (Johnson and Lewis, 1995: 204;Young, 1992).…”

“…Hundreds of new landforms can be created in a very short time through the removal of huge quantities of overburden, resulting in high-relief landforms, which then have the potential for failure and associated environmental and hydrologic problems (Nyssen and Vermeersch, 2010). Use of geomorphic principles to understand mined land reclamation is relatively recent, as early efforts at land reclamation commonly created a distinctive landform suite (Haigh, 1978).…”

Potential conflicts connected with the recovery of secondary materials from post mining waste dump

“…These are mainly hard coal basins, such as Ruhr Basin in Germany, Belgian Northern and Southern Basin (Campine and Liége), South Wales Basin, Ostrava-Karvina Coalfield in Czech Republic or Upper Silesian Coal Basin (USCB) in southern Poland (GABZDYL, 1994;SCHULZ, 2004;MARTINEC ET AL., 2006;NYSSEN & VERMEERSCH, 2010).…”