Impact of anthropogenic activities on airflow field variation over a star dune

Star dune, the most complex type of single dune ever found, is known to be controlled by several natural factors including wind, topography, and sediment source. Anthropogenic impact of direct disturbance or modification on nearby land surface can also alter its shape and pattern over a longer timescale, but this factor is generally overlooked. Here, we present an integrated study of anthropogenic impact on a well-known star dune in the Mingsha Megadune of Dunhuang, China, by using 3D full-scale numerical simulations and wind tunnel experiments with printed 3D solid models. The removal of the tail of one dune arm affects both the leeward recirculation zone and the budge of dune surface; and an enlarged peripheral green land affects wind speed redistribution and dune body displacement. The wind speed and direction variations were confirmed by field observations. We suggest that anthropogenic impact should be reduced to minimum or used to restore the setting to its previous state, for example, by removing the newly planted trees and rebuilding the dune arm tail, to maintain the natural balance between wind regime and aeolian landform, in order to protect this precious nature heritage from further deformation and degradation.