大渡河上游丹巴地区地质灾害的地貌分维特征解析

地貌对地质灾害的分布、类型、规模与危害等特征具有重要的影响,宏观及微观地貌指标均能在一定程度上刻画其作用特征。应用高分辨率遥感影像详细解译崩塌和滑坡灾害,采用高精度DEM和滑动窗口技术提取地貌分维特征,并用其解析灾害分布的地貌特征。结果表明:灾害体的内部与后壁、前缘、侧壁和邻区均表现出较为明显的分异性,崩塌的微地貌分异特征较之滑坡显著,大型、厚层、老(古)崩塌及滑坡分异特征更为突出。计算地貌分维值可有效识别与其同时期的或更早的地质灾害,也可间接挖掘新发生灾害的微地貌复杂性和离散性。

Geomorphologic Fractal Dimension Analysis of Geological Disasters in Danba Area at the Upstream of the Dadu River, China

Topography observably affects type, distribution, size, and harm of geological disasters. Different scales of geomorphologic indicators can reflect different effects of geological disasters. Based on high resolution remote sensing images, collapse and landslide disasters were interpreted in detail, and topography fractal dimension map of high-precision DEM was applied to analyze the micro geomorphologic feature of disasters. The research shows that the internal, scarp, front edge, side edge and adjacent area have obvious differentiation; the differentiation of rock fall is more significant than landslide, and the large, thick, old (ancient) collapse and landslides are 30 times higher. The contemporaneous or earlier geological disasters could be reflected by the fractal dimension of topography directly, and so do the geomorphologic complexity and discrete of new disasters.