InSAR在云南德钦县一中河泥石流物源汇集及失稳模式中的探究

针对传统方法难以定量描述大尺度泥石流形成机理的问题，提出一种联合SAR卫星影像相位信息和后向散射信息全面识别泥石流发育机制的方法，并使用该方法探究云南省德钦县一中河泥石流物源汇集及失稳模式。通过后向散射系数反演研究区土壤含水量的时空变化趋势，利用升降轨Sentinel-1A数据获取坡表二维形变。结果表明，研究区土壤含水量与地表形变表现出周期性和强关联性，早期物源汇集受干湿循环影响，1~6月土壤含水量增加，表土受高孔隙压作用出现膨胀现象；7~12月受风化侵蚀作用，表层物源剥落，为泥石流形成区补给物源。通过小基线技术(SBAS-InSAR)获取地表时序形变，结果表明，失稳模式为年初干旱导致土体不稳定，后由暴雨冲刷激活。该方法可为InSAR技术在泥石流发育机制解译方面提供新思路，对泥石流灾害具有预警及预报作用。

InSAR Study on Substance Source Collection and Instability Mode of Yizhong River Debris Flow in Deqin,Yunnan Province

We propose a method to identify the development mechanism of debris flow by combining the phase information and backscatter information of SAR image, so as to explore the substance source collection and instability mode of debris flow in Yizhong river of Dêqên county, Yunnan province. The spatial-temporal variation trend of soil moisture in the study area is inversed by backscatter coefficient, and the two-dimensional deformation of slope surface is obtained by using ascending and descending orbit sentinel-1A data. The results show that the soil moisture and surface deformation in the study area show periodicity and strong correlation, and the early source collection is affected by the dry-wet cycle. The soil moisture increases from January to June, and the surface soil expands under the action of high pore pressure. The surface material source is stripped and transported downward, affected by wind from July to December, supplying material source for the debris flow forming area. Using SBAS-InSAR to obtain the time series deformation of the surface reveals that the soil is unstable due to drought at the beginning of the year, later activated by rainstorm scouring. The method we propose provides a new idea for InSAR technology in the interpretation of debris flow development mechanism and has the function of early warning and prediction for debris flow disasters.