白格滑坡-碎屑流堆积体颗粒识别与分析

Recognition and analysis of deposit body grain of Baige Landslide-Debris Flow

受到滑坡-碎屑流灾害瞬时性及致灾性极强的影响,滑坡-碎屑流灾害往往极难直接观察研究。对其堆积体颗粒的研究是滑坡-碎屑流研究极好的切入点。为方便快捷的统计分析堆积体颗粒粒径分布,采用无人机航拍与图像识别技术相结合的方式获取堆积体粒径数据,并将PCAS软件运用于堆积体粒径识别,并提出"无人机航拍-PCAS图像识别"的粒径分析工作方法。以2018年11月3日发生的白格滑坡-碎屑流为研究案例,对滑坡-碎屑流堆积体粒度分布进行统计分析。结果显示:(1)PCAS软件能有效识别堆积体颗粒粒径;(2)堆积体中小粒径占了绝大多数,随滑坡-碎屑流运动距离增加,小粒径含量增加,且大粒径出现"双峰"现象;(3)白格滑坡斜坡堆积面密度与斜坡坡度之间存在一定关系,并推导建立了其关系的经验公式;(4)堆积体形态特征参数的变化能侧面反应滑坡-碎屑流的运动过程及运动特性。对白格滑坡-碎屑流堆积体颗粒的研究结果表明,PCAS软件应用于堆积体粒径统计分析是可靠的,能在滑坡-碎屑流研究领域发挥一定的作用。

Under the strong impact from the instantaneity and catastrophability of the disaster of landslide-debris flow, it is quite difficult to be directly observed and studied in most cases. The study on the grain of the deposit body of landslide-debris flow is a better entry point of the study made on the disaster. In order to conveniently and quickly make a statistical analysis on the particle size distribution of the deposit body grain, the method of combining UAV(unmanned aerial vehicle) aerial photography with image recognition technique is adopted to obtain the data of the particle size of the deposit body grain, and then the software of PCAS-Particles(Pores) and Cracks Analysis System is applied to recognise the particle size of the deposit body grain, while the working method of analyzing the particle size through UAV aerial photography-PCAS image recognition is put forward herein as well. By taking Baige Landslide-Debris Flow occurred on November 3, 2018 as the study case, the particle size distribution of the deposit body grain of the landslide-debris flow is statistically analyzed. The analysis result shows that(1) PCAS software can effectively recognise the particle size of the deposit body grain;(2) the particle sizes of most of the grains in the deposit body are small and middle, while the grains with small particle size are increased along with the increase of the moving distance of the landslide-debris flow, and a phenomenon of bimodal distribution of the grains with large particle size appears;(3) a certain relationship is there between the surface density of the deposit body and the slope gradient of the slope of Baige Landslide, for which an empirical formula is derived and established;(4) the moving process and motion characteristics of the landslide-debris flow can be reflected from the side by variations of the parameters of the morphological characteristics of the deposit body. Generally, the result from the study made on the grain of the deposit body of Baige Landslide-Debris Flow shows that the application of PCAS software to the statistical analysis of the particle size of the grain of the deposit body is reliable, thus can play a certain role in the field of the study on landslide-debris flow.