十大孔兑地区风沙运动及沉积特征数值模拟OA

The Ten Tributaries region in Inner Mongolia,shaped by alternating wind and water erosion,has developed a stepped gully landform and become a major sediment source for the Yellow River.To in-vestigate the transport and deposition patterns of aeolian sand under complex topography,we extracted typical profile characteristics based on three-dimensional aerial photogrammetry data to establish a simpli-fied geomorphic boundary,and then used the discrete phase model(DPM)in Computational Fluid Dy-namics to simulate the sand deposition process in gullies at various channel locations.The results demon-strate that the stepped gully significantly alters the near-surface wind field;its steep slopes induce strong airflow separation and reverse vortices,leading to a sharp dissipation of kinetic energy at the gully bottom and forming a highly efficient"sediment trap".Concurrently,the shielding and blocking effects of the terrain intensify as the gully deepens and widens,resulting in a significantly increasing trend in cumula-tive sand deposition from the end to the root of the channel,and making the channel root the primary core area for aeolian sand accumulation.This mechanism verifies the"source-sink"conversion function of the gully terrain—storing sand during the dry season and transporting sand during the rainy season.This indicates that controlling aeolian sand accumulation at the channel root is a crucial link in managing the sediment load entering the Yellow River.