对地质灾害隐患早期识别相关问题的认识与思考

泥石流物源识别与计算是科学评估泥石流规模、危害程度以及综合治理的基础,而传统的地面调查和光学遥感手段难以有效识别山区植被茂密覆盖下的泥石流物源。机载激光雷达（light detection and ranging,LiDAR）技术能有效去除植被获取真实的地表形态,为泥石流物源的识别提供了新的解决方案。以九寨沟震区的日则沟泥石流为例,基于高分辨率机载LiDAR数据结合震前卫星影像,开展泥石流物源识别研究,根据物源所处位置和在山体阴影图像上的色彩及纹理差异,将物源分为崩滑物源、坡面物源和沟道物源,并建立各类型物源的机载LiDAR识别标志与遥感解译方法。共解译出日则沟泥石流物源155处,总面积达1.06 km²,占流域总面积的31.56%,在此基础上分析了各类型物源的发育分布规律。为泥石流物源的精确计算提供理论参考和数据支撑,进一步服务于九寨沟震区泥石流的防治与风险评价。

Understanding and Consideration of Related Issues in Early Identification of Potential Geohazards

The quantification of debris flow material sources is the basis of scientific evaluation of debris flow scale, degree of disaster and comprehensive management. It is difficult to identify debris flow source under dense vegetation by traditional ground survey and optical remote sensing in lush mountainous areas of southwest China.Comparatively, airborne light detection and ranging(LiDAR) technology can effectively remove vegetation to obtain high resolution digital elevation model, providing a new solution for debris flow source identification. Taking the Rize basin debris flow in Jiuzhaigou earthquake area as a case study, we propose a new methodology for interpretation debris flow source based on high-resolution LiDAR data. The material sources are divided into slump-mass source, gully sediments source and slope wash source, and we propose geomorphologic identification masks and remote sensing interpretation to regard different types of debris flow source.A total of 155 debris flow material sources in Rize basin debris flow are interpreted, covering an area of 1.06 km², accounting for 31.56% of the total basin. On this basis, the characteristics and distribution law of various types of material sources are analyzed.The results provides theoretical reference and data support for the quantification of debris flow source and debris flow prevention and risk assessment of the earthquake area in Jiuzhaigou.