The splash process in aeolian transport: Phenomena, mechanisms, regulations, advances and prospects

Aeolian transport is an important mechanism for sand movement on both Earth and Mars. A critical component of this process is the splash event, where saltating grains rebound and eject bed particles upon impact, which are critical for sustaining aeolian transport and shaping the morphological evolution of related landforms. Accurately understanding and predicting the dynamic behavior of the splash process is key to integrating this process into sand transport models and enhancing predictive accuracy. However, a systematic review of the splash process in aeolian sand transport is still lacking. This review comprehensively summarizes mechanisms, regulations, and methodologies of the splash process in aeolian sand transport. It emphasizes the critical aspects of particle rebound and ejection, discussing their fundamental principles, dynamic laws, and influencing factors in detail. It also compares and analyzes the outcomes of various research methodologies, elucidating the differences and their causes. Furthermore, the review evaluates the implementation of these methods and their findings, specifically how wind regimes, impact angles, impact velocities, and bed surface characteristics influence the dynamics and behaviors of the splash process. Finally, it highlights existing challenges and proposes future research directions from both scientific and practical perspectives. This review aims to provide a theoretical foundation and research direction for developing more precise and broadly applicable splashing models.