分类： 地球科学 >> 地理学 提交时间： 2021-04-22 合作期刊: 《干旱区科学》
摘要： Deserts are ideal places to develop ground-mounted large-scale solar photovoltaic (PV) power station. Unfortunately, solar energy production, operation, and maintenance are affected by geomorphological changes caused by surface erosion that may occur after the construction of the solar PV power station. In order to avoid damage to a solar PV power station in sandy areas, it is necessary to investigate the characteristics of wind-sand movement under the interference of solar PV array. The study was undertaken by measuring sediment transport of different wind directions above shifting dunes and three observation sites around the PV panels in the Hobq Desert, China. The results showed that the two-parameter exponential function provides better fit for the measured flux density profiles to the near-surface of solar PV array. However, the saltation height of sand particles changes with the intersection angle between the solar PV array and wind direction exceed 45°. The sediment transport rate above shifting dunes was always the greatest, while that around the test PV panels varied accordingly to the wind direction. Moreover, the aeolian sediment transport on the solar PV array was significantly affected by wind direction. The value of sand inhibition rate ranged from 35.46% to 88.51% at different wind directions. When the intersection angle exceeds 45°, the mean value of sediment transport rate above the solar PV array reduces to 82.58% compared with the shifting dunes. The results of our study expand our understanding of the formation and evolution of aeolian geomorphology at the solar PV footprint. This will facilitate the design and control engineering plans for solar PV array in sandy areas that operate according to the wind regime.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2018-04-24 合作期刊: 《干旱区科学》
摘要： The rapid desertification of grasslands in Inner Mongolia of China poses a significant ecological threaten to northern China. The combined effects of anthropogenic disturbances (e.g., overgrazing) and biophysical processes (e.g., soil erosion) have led to vegetation degradation and the consequent acceleration of regional desertification. Thus, mitigating the accelerated wind erosion, a cause and effect of grassland desertification, is critical for the sustainable management of grasslands. Here, a combination of mobile wind tunnel experiments and wind erosion model was used to explore the effects of different levels of vegetation coverage, soil moisture and wind speed on wind erosion at different positions of a slope inside an enclosed desert steppe in the Xilamuren grassland of Inner Mongolia. The results indicated a significant spatial difference in wind erosion intensities depending on the vegetation coverage, with a strong decreasing trend from the top to the base of the slope. Increasing vegetation coverage resulted in a rapid decrease in wind erosion as explained by a power function correlation. Vegetation coverage was found to be a dominant control on wind erosion by increasing the surface roughness and by lowering the threshold wind velocity for erosion. The critical vegetation coverage required for effectively controlling wind erosion was found to be higher than 60%. Further, the wind erosion rates were negatively correlated with surface soil moisture and the mass flux in aeolian sand transport increased with increasing wind speed. We developed a mathematical model of wind erosion based on the results of an orthogonal array design. The results from the model simulation indicated that the standardized regression coefficients of the main effects of the three factors (vegetation coverage, soil moisture and wind speed) on the mass flux in aeolian sand transport were in the following order: wind speed>vegetation coverage>soil moisture. These three factors had different levels of interactive effects on the mass flux in aeolian sand transport. Our results will improve the understanding of the interactive effects of wind speed, vegetation coverage and soil moisture in controlling wind erosion in desert steppes, and will be helpful for the design of desertification control programs in future.
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