Wind environment of grottoes over a complex mountain using UAV field measurements and numerical simulation

The wind environment of grottoes across Northwest China is affected by complex mountainous terrain, making semi-open stone carvings vulnerable to wind erosion. This study uses the Xumishan Grottoes as a representative site in complex mountainous terrain to investigate the local wind environment. First, field wind measurements were conducted at the Xumishan Grottoes, and an unmanned aerial vehicle (UAV) was employed to optimize the testing of the boundary condition at the grottoes’ entrance. Second, an efficient terrain modeling workflow for complex mountainous settings was developed. Finally, an interpolation multiscale profile (IMP) method for numerically simulating wind fields in complex mountainous terrain was proposed. The results indicate that UAV-based oblique photogrammetry enables rapid acquisition of high-resolution digital surface models (DSM), while the IMP-based simulations provide detailed near-surface wind fields. The study clarifies how mountainous terrain governs grottoes’ wind environments and provides scientific support for mitigating wind erosion and advancing preventive conservation of stone cultural heritage.