Spatial patterns and influencing factors of debris flows in the middle Yarlung Zangbo River on the Tibetan Plateau

Currently, studies concerning geological disasters in the Yarlung Zangbo River Basin on the Tibetan Plateau predominantly focus on the Grand Bend downstream of the river. However, research about the spatial patterns and influencing factors of debris flow disasters in the middle reaches remains relatively unclear. Based on remote sensing interpretation, field investigation, and the frequency ratio method, the characteristics of debris flows in the middle Yarlung Zangbo River were analyzed, and the control effects of six factors, e.g. topography, geology, and rainfall on the development patterns of debris flow gully were studied. Research has uncovered the main findings below: 1) the 181 debris flows within the region can be classified into three types according to the water source conditions, each of which exhibits predominantly low-frequency, dilute, and giant-scale occurrences. 2) for the endogenic and exogenic dynamics, lithology has the strongest control effect on debris flows; in terms of topography and vegetation, NDVI (Normalized Differential Vegetation Index) has the strongest control effect on debris flows. 3) Finally, we identified the section from the Naidong District of Shannan City to Nang County of Linzhi City as the area susceptible to debris flow.