矿区土地利用生态风险的时空异质性

Spatial-temporal heterogeneity of ecological risk of land use in mining areas

以微山县煤矿较集中、地面塌陷较严重的11个乡镇作为研究区,以遥感影像和土地利用现状数据为数据源,获取4期土地利用类型分布图,根据景观生态学理论构建景观意义上的土地利用生态风险指数,结合空间统计学及地统计学理论,探究2000—2016年研究区适宜尺度下土地利用生态风险的时空变化情况及空间异质性。结果表明:1 km×1 km规则网格是最佳研究尺度,在该尺度下研究区土地利用生态风险的空间分布呈集聚模式,且具有很强的空间正相关性;2000—2005年土地利用生态风险指数在小尺度上的随机变异逐渐被较大尺度上的空间结构性变异所取代,2005年生态风险总的空间变异程度较高,2005—2016年随机因素引起的空间变异程度增强;2000—2016年土地利用生态风险呈现由中高、高生态风险向中、中低生态风险转变的特征;生态风险恶化区和明显恶化区主要分布在东部矿区周边、道路沿线、地面塌陷较严重的区域,研究区西南部微山湖沿岸东西两侧,耕地的生态风险恶化程度2010—2016年较高;17年间微山湖湖区的生态风险稳定区和改善区大幅增加,生态风险明显下降。

In this study,the 11 towns with the most coal mines and serious surface collapses in Weishan County were selected as the areas of study,and remote sensor images and land use data were used as the data sources.From this information,distribution maps of land use type in 2000,2005,2010 and 2016 were obtained.Based on landscape ecology theory,an index of the ecological risk of land use was constructed.In this study,the theories of spatial statistics and geostatistics were used to determine an appropriate study scale.Spatial-temporal change and spatial heterogeneity of the ecological risk of land use in the research area were analyzed between 2000 and 2016.It was concluded that 1 km×1 km regular grid was the best research scale.At this scale,the spatial distribution of the ecological risk of land use in the research area was concentrated and had a strong positive spatial correlation.The random variation of the land use ecological risk index on a small scale was gradually replaced by spatial structural variation on a larger scale between 2000 and 2005.The total spatial variability of ecological risk in 2005 was high.Between 2005 and 2016,the degree of spatial variability caused by random factors was increased.Between 2000 and 2016,the ecological risk of land use was characterized by the transition from medium-high and high ecological risk to medium and medium-low ecological risk.The ecological risk of deteriorated areas and obviously deteriorated areas was mainly distributed around the eastern mining area,roadside,and serious collapse areas.In addition,the ecological risk of deterioration of cultivated land on both sides of the east and west side of Weishan Lake was higher between 2010 and 2016.Over the past 17 years,the stable areas and improved areas of Weishan Lake increased significantly,with a clear decrease in the overall ecological risk.