Abstract:

The relative height of dunes serves as a pivotal parameter in understanding the formation and evolutionary dynamics of aeolian landforms. Accurate determination of the base point for dune height measurement is crucial for this parameter's quantification. Traditional manual measurement techniques are not feasible for extensive studies due to their limitations in scalability and subjectivity involved in selecting base points. Furthermore， existing digital terrain analysis algorithms have not adequately addressed the criteria for base point selection. This study introduces the concept of contribution efficiency to quantify the significance of local terrain minima in contributing to the relative height of dunes. Utilizing this concept， the most appropriate base point is identified from among numerous local minima adjacent to the dune crest. An analysis comparing two deserts with three distinct types of terrain data demonstrates that： （1） The proposed method for base point selection outperforms previous techniques in terms of both spatial distribution and height value accuracy； （2） The error associated with horizontal data resolution exceeds that of elevation accuracy， with dunes less than 50 meters in height being particularly susceptible to such errors； （3） The maximum dune height as determined by this method aligns closely with field measurements. This research facilitates large-scale， objective， and fully automated dune height measurement， which holds potential for global application. It represents an innovative approach to the morphometric analysis of dunes and offers a valuable reference for base point selection in field surveys.

Key words: relative dune height, dune base point, contribution efficiency, digital elevation modeling, Badain Jaran Sand Sea