Abstract: In order to explain the dynamic mechanism of sand erosion and accumulation of sandy surface under the interference of photovoltaic facilities, two cross sections were set in the 110 MW photovoltaic Plant located in the Hopq Desert. MetOne 014A/024A 8 channel anemometer (with CR200X data collection instrument) were used, and the average wind speed of four heights (20 cm, 50 cm, 100 cm, 200 cm) around the photovoltaic panel were observed simultaneously. The variations of wind velocity around the photovoltaic panel were analysed. Results showed that:(1) The photovoltaic facilities resulted in the variations of flow field on both sides of the photovoltaic panels and generated four secondary flow field zones, namely, the conflux accelerating speed-up zone under the panels, the resistance decelerating zone in front and back of the panels, the uplift zone above the panels and the recovery area between the plates; Moreover, there were significant differences in the flow field pattern between the upwind edge region and the area within the photovoltaic plants. (2) The dynamical distribution indicated by develop degree of the flow field pattern was identical with the surface erosion and accumulation situation basically. (3)Vegetation can increase the surface roughness effectively, and reduce the transit speed below 50 cm near surface, and prevent the occurrence and aggravation of the sand erosion. (4) The conflux accelerating zone under the panels and the reverse vortex around the panels were the main dynamic mechanisms of shaping wind erosion ditches (PITS) and sand accumulation belts, respectively.

Key words: photovoltaic plant, secondary blown sand disaster, wind profile, flow field pattern, erosion and deposition situation