石羊河流域土地利用变化分形特征研究

利用石羊河流域1980、1995、2000、2006、2012年5期遥感影像，应用分形理论和GIS方法研究石羊河流域土地利用变化分形特征，定量分析流域不同土地利用类型变化的复杂性、稳定性以及变化趋势。结果表明：总体上流域耕地、城乡工矿居民用地、林地和水域呈现增加趋势，未利用地和草地呈现减少趋势，不同时段土地利用类型都具有空间分形结构，不同土地利用类型复杂性和稳定性呈现波动变化趋势。1980、1995、2000年石羊河流域不同土地利用类型分维数排序均为：水域＞耕地＞林地＞草地＞未利用土地＞城乡工矿居民用地。2006、2012年分维数由高到低依次为：水域、耕地、草地、林地、未利用土地和城乡工矿居民用地。1980、1995、2000、2006、2012年石羊河流域总平均分维值分别为1.5296、1.5025、1.5445、1.5631、1.5676，不同土地利用类型平均分形维排序为水域(1.8317)＞耕地(1.5678)＞林地(1.5351)＞草地(1.5315)＞未利用土地(1.4413)＞城乡工矿居民用地(1.3411)。总平均稳定性指数分别为0.1083、0.0997、0.1228、0.1167和0.1186，不同土地利用类型平均稳定性排序为水域(0.3317)＞城乡工矿居民用地(0.1589)＞耕地(0.0635)＞未利用土地(0.0587)＞林地(0.0351)＞草地(0.0315)。通过对流域土地利用变化复杂性、稳定性以及动态变化研究，为区域土地资源合理开发与生态环境协调发展提供技术支撑与决策依据。

Fractal Characteristics of Land Use Change in Shiyang River Basin

Using fractal theory and GIS method with remote images in 1980, 1995, 2000, 2006 and 2012, fractal characteristics of land use change were studied and the complexity, stability and dynamic change tendency of different land use types change were quantitative analyzed in Shiyang river basin. The results showed that cultivated land, urban and rural residential land and industrial and mining land, forest land and water area had taken on increase tendency, and unused land and grassland had decrease tendency in last 33 years in Shiyang river basin. The different period land use types had the spatial fractal structure, and the complexity and stability of different land use types took on fluctuant change tendency in Shiyang river basin. The order of the value of fractal dimension of different land use types were as follows: the fractal dimension value of water area ＞ that of cultivated land ＞ that of forest land ＞ that of grassland ＞that of unused land ＞ that of urban and rural residential land and industrial and mining land in 1990, 2000 and 2005, and from high to low order were water area, cultivated land, grassland, forest land, unused land, urban and rural residential land and industrial and mining land in 2006 and 2012, respectively. The average fractal dimension values of land use of Shiyang river basin were 1.5296, 1.5025, 1.5445, 1.5631 and 1.5676 in 1980, 1995, 2000, 2006 and 2012, respectively. The average fractal dimension values of different land use types arranged in number order from big to small were as follows: water area (1.8317) ＞ cultivated land (1.5678) ＞ forest land (1.5351) ＞grassland (1.5315) ＞unused land (1.4413) ＞ urban and rural residential land and industrial and mining land (1.3411) in Shiyang river basin. The average stability index of land use of Shiyang river basin were 0.1083, 0.0997, 0.1228, 0.1167 and 0.1186 in 1980, 1995, 2000, 2006 and 2012, respectively. The average stability index of different land use types arranged in number order from big to small were as follows: water area (0.3317) ＞ urban and rural residential land and industrial and mining land (0.1589) ＞cultivated land (0.0635) ＞unused land (0.0587) ＞ forest land (0.0351) ＞grassland (0.0315) in Shiyang river basin. The research of fractal complexity, stability and change tendency characteristic of land use change would provide decision-making basis and technical support for coordinating development between rational exploitation and utilization of land resources and ecological environment in region.