Effects of coal exploitation on land use and landscape pattern change in coal mining area

Abstract: Mining areas with intensive resources exploitation and utilization have undergone different kinds of environmental influences, such as water pollution and land use and land cover change (LUCC). The extensive coal mining in China has led to significant regional land use change resulting in major ecological damage. In order to research the impact of coal exploitation on landscape pattern change in coal mining area, taking Peibei mining area in Xuzhou City, Jiangsu Provinces, China as an example, the changes in land use and landscape pattern were analyzed quantitatively based on remote sensing (RS), geographic information system (GIS), landscape ecology and mathematical statistics. Influence of the scale and intensity of coal mining on variation process of land use structure and landscape pattern was mainly studied from the perspective of coal industry life cycle. At the same time, the driving factors of land use and landscape pattern change were analyzed from coal mining, economy, urbanization and land reclamation policy. The results were as follows: 1) Over the last 20 years the landscape structure and landscape pattern of land use in the mining area have changed significantly with the continuous exploitation of coal resources, which were mainly manifested by the decrease of cultivated land, forest land and unused land and the rapid increase of industrial and mining construction land and subsidence water. In particular, the subsidence water increased from 56.38 hm2 in 1994 to 1254.31 hm2 in 2014, and increased by about 22 times. The process of farmland transformed into construction land and subsidence water has become intense and frequent since 2000, in which the coal mining area has been in stable exploitation period. 2) Landscape type index showed a rising trend in fluctuation and landscape fractal characteristics tended to be simplified and regularized. The patch type index of cultivated land, forest land and garden plot overall declined, but that of industrial and mining construction land and the subsidence water increased continuously, which indicates the landscape of mining area tended to be simple and uniform. 3) Furthermore, correlation analysis and Mann-Kendall abrupt change test show that there is a strong correlation between coal resources exploitation and landscape index change. The abrupt changes of largest patch index (LPI) and aggregation index (AI) of cultivated land occurred in 1999 and 2001 respectively, and showed a rapid downward trend in 2003, which shows that the coal resource exploitation first affects the landscape dominance of cultivated land and then influences the aggregation degree of cultivated land patches with the increase of coal mining intensity. The AI of subsidence water area had a significantly rising trend in 2 periods, 1997-2006 and 2011-2013, but no significant change in 2006-2011, and the LPI of subsidence water area was increasing gradually over the whole period. The main reason is that continuous large-scale exploitation of coal resources seriously resulted in ground subsidence, damage and loss of arable land, vegetation field reduction and landscape fragmentation, and that the management of subsidence area got some effects through land reclamation and landscape restoration in mining area, which were showed as the increase of cultivated land and water area, and the decrease of landscape fragmentation. These results provide an important guide for land reclamation and ecological restoration of damaged landscape in coal mining areas.