Disaster attributes and distribution laws of debris flows in the upper Parlung Zangbo River

The upper Parlung Zangbo River exhibit extremely active endogenic and exogenic dynamics, with various types of debris flows posing significant hazards. Research on the distribution laws and fundamental attributes of these debris flows is crucial for efficient prevention and control measures. Through field investigations, remote sensing interpretation, and Frequency ratio method, a total of 87 debris flows have been identified along the upper Parlung Zangbo River. The Disaster attributes of debris flows have been analyzed, and six disaster-prone factors, including slope, NDVI, and lithology, have been selected. Moreover, the distribution of disaster-prone factors for debris flows in this section has been calculated, revealing the distribution patterns of debris flow disasters. The results are as follows: (1) The disaster attributes of debris flows include the following: influenced by the coupling effect of multiple factors, spatial variability and mass occurrence, nocturnal and periodic effects in time and high risk of debris flows. (2) for the endogenic and exogenic dynamics, mean annual precipitation has the strongest control effect on the distribution of debris flows, followed by lithology and peak ground acceleration (PGA); in terms of topography and vegetation, NDVI has the strongest control effect on the distribution of debris flows. (3) By integrating the distribution patterns of these factors, the predominant sections for debris flow development are ranked as follows: Bomi County to Songzong Town, Ranwu to Yupu Township, and Yupu Township to Songzong Town. The research results support the prevention and control of debris flow in the whole life cycle of the construction, management, and operation of the linear project on the Tibetan Plateau.