Dynamic changes of land use fractal characteristic in mining area

Abstract: With the rapid development of economy and society, a series of ecological and environmental problems (e.g., land damage, surface subsidence, stagnant water and soil pollution) became increasingly serious in some mining area such as Xuzhou, Jiangsu province. In addition, resources shortage also becomes more and more severely. The land reclamation and ecological reconstruction might act as an important resolution in solving human-land conflict and improving ecological environment. However, the land use structures, and hence the fractal feature of land, are becoming more and more affected due to coal mining, land reclamation and urbanization. In order to reveal the spatial behavior and the dynamics of land use in the northern coal mining area in Xuzhou, three scenes of Landsat images were collected in the years of 1987, 2000 and 2011. Four fractal exponents (the patch shape fractal dimension, box-counting dimension, radius dimension and ramification dimension) were analyzed from several aspects. The complexity, stability, space occupation ratio, attenuation and mutual penetration were investigated by using GIS. The analysis results indicate that fractal features of land use are obviously in the coral mining area in Xuzhou city. On the other hand, the fractal features of different kinds of land use type have changed in the process of coal mining, land reclamation and urbanization. To be specific, both the patch shape, fractal dimension and the ramification dimension show the increasing trend firstly, and then decreasing, which is influenced by coal exploitation and land reclamation. The patch shape fractal dimension has been increasing and tends to be unstable, which is affected by the urban land development in the urban and mining areas; The box-counting dimension and the radius dimension in farmlands showed an increasing trend owing to fragmented landform and sporadic subside seeper area due to the coal exploitation. Additionally, the box-counting dimension and the radius dimension of the water area showed an increasing trend because of the increasing of the water patches' area in the process of the land reclamation in coral mining area; In summary, the land reclamation and urbanization are the main driving factors of both the fractal features changing and structure stability in northern coal mining area in Xuzhou. It is therefore necessary to strengthen the reconstruction of ecological environment, improve the technical regulation for mine reclamation and establish ecological restoration strategy for achieving the sustainable development in some traditional coal mining areas.