Morphology of Alluvial Fan Longitudinal Profiles in the Parlung Tsangpo Basin

The longitudinal profile (LP) of an alluvial fan is a fundamental morphological feature that records formation processes and distinguishes fan types. Here, we quantitatively analyze LP morphology using data from 18 alluvial fans in the Parlung Tsangpo Basin (PTB) in southeast Tibet—an alpine valley basin hosting fluvial, colluvial, and debris-flow fans (FF, CF, and DF) shaped by distinct dominant processes. The data include the geomorphological characteristics of alluvial fans (location, area, length, mean slope, etc.), longitudinal profile concavity, local slope variability parameters, and corresponding channel longitudinal profile characteristics.This work aims to clarify morphological differences in the LPs of distinct alluvial fan types and provide data support for fan type identification.冲积扇纵剖面（Longitudinal Profile，LP）是记录其形成过程、区分扇体类型的基础地貌学特征。本研究以西藏东南部帕隆藏布盆地（Parlung Tsangpo Basin，PTB）内的18处冲积扇为研究对象，定量分析其纵剖面形态特征；该盆地为受不同主导营力塑造的高山河谷盆地，发育河流冲积扇（fluvial fan，FF）、坡积扇（colluvial fan，CF）与泥石流扇（debris-flow fan，DF）三类扇体。本次研究所用数据集涵盖冲积扇的基础地貌参数（包括位置、面积、长度、平均坡度等）、纵剖面凹度、局部坡度变异参数，以及对应河道的纵剖面特征。本研究旨在厘清不同类型冲积扇纵剖面的形态差异，为扇体类型识别提供数据支撑。