Comprehensive Analysis of Characteristics of Debris Flow Fans in Xiaojiang Valley by Using Remote Sensing Method

With the continuous improvement of the spatial resolution of remote sensing images, its application in geosciences is more and more extensive. Xiaojiang Valley is a place where debris flow often breakout in China. Due to the frequent occurrence of debris flow, many debris flow fans have been formed in the valley. In this paper, we use the methods of visual interpretation by using GF2 images and field investigation to find that there are a total of 196 debris flow fans in the Xiaojiang River Valley. The GIS technology is used to analyze the area, spatial distribution, slope and plane shape of these debris flow fans. The results show that the debris flow fans in the study area are mainly medium-size and large-size debris flow fans, and the total area of 196 debris flow fans is 65.709km
²
; In terms of spatial plane distribution characteristics, 64% of the debris flow fans are distributed along the main river and the branch Kuaihe River of Xiaojiang River; In terms of elevation and percentage slope characteristics, debris flow fans are the most widely distributed in the areas which the elevation between 1000m-1500m or the percentage slope between 15% -30%; In terms of morphological characteristics, the length-width ratio of debris flow fans in the range of 0.5-1.0 is the most.