矿区土地生态风险时空分异研究

Study of spatial-temporal change of land eco-risk in mining area

以徐州市贾汪矿区1983,1993,2003和2013年4期遥感影像为数据源,利用层次分析法等确定不同土地利用类型的生态风险强度,构建土地生态风险指数,借助空间相关分析、地统计分析对区域生态风险的时空分异进行分析.结果表明:4期土地生态风险全局空间相关系数均为正值,表明矿区土地生态风险表现出较强的空间集聚特征;矿区生态风险从中生态风险、较高生态风险向低生态风险和高生态风险转移,即生态风险格局朝两极发展;生态风险的时空变化较明显,采煤塌陷区生态风险由于矿区土地复垦的实施,生态风险有所降低,城区东部、北部由于城市空间扩展,景观破碎化程度较高,成为高生态风险区;东部作为粮食主产区受城市化和复垦项目的影响较小,生态风险一直处于较低状态.因此,在矿区土地复垦项目实施过程中通过区域生态风险的变化对土地利用结构进行调整,使矿区土地复垦的生态效益和社会效益达到最大化.

The spatial-temporal differentiation characteristics of land use eco-risks were ana- lyzed by means of spatial statistics like spatial autocorrelation and semi-variance analysis based on the remote sensing data in 1983,1993,2003 and 2013 of Jiawang coal mining area in Xuzhou. The land use eco-risk index was constructed by determining the weight values of different land use patterns by analytic hierarchy process etc. The results showed that： the eco-risk degree of land use was positive correlation and characterized by spatial connection. Coal mining and land reclamation of mining area project bring great changes in regional landscape structure. Regional ecological risk presents a transfer from ecological risk and higher ecological risk to low ecologi- cal risk and high ecological risk, that is, the ecological risk pattern is heading towards the poles. The temporal and spatial dynamic change of ecological risk is obvious, due to the imple- mentation of the land reclamation of mining area , ecological risk in coal mining subsidence area has decreased, and in the east and north of the city ,the degree of landscape fragmentation in- creased by the urban expansion ,making it a high ecological risk area; as an area of major grain producing area, the eastern part has been less affected by urbanization and reclamation pro- jects, and its ecological risk has been at a low ecological risk region. Therefore, in the process of implementation of the land reclamation projects in the mining area, we could maximize social benefits and economic benefits of land reclamation of mining area through the change of region- al ecological risk and adjusting land use structure.