Numerical simulation of flow field structure and sand accumulation around railway subgrade.

Based on the current situation of railway sand damage in Tuotuohe region, the structure of wind-sand flow and the spatial distribution characteristics of sand particles on both sides of railway embankment are simulated by CFD Fluent software according to flow field measurement and wind tunnel test.The results demonstrate that the subgrade's shoulders are vulnerable to suffering from wind erosion; The sand particles' spatial deposition location and thickness are significantly affected by the incoming wind velocity and the railway subgrade. When the low incoming sand-carrying wind velocity, a lot of sand grains fall and are deposited at the railway embankment slope foot due to the sand-carrying wind velocity reduced.

Evaluation of windproof and sand fixation effect of protective system in the Desert oasis ecotone of Mingsha Mountain Dunhuang.

The Desert oasis ecotone (DOE) protects the oasis from wind and sand intrusion, thereby playing a crucial role in controlling desertification. However, there is limited knowledge about how DOE functions in windproof and sand-fixation. Therefore this study employs a three-dimensional (3D) laser scanner to monitor surface accumulation and erosion, and through field observations, collects data on wind profiles, grain size, and sand transport rates to uncover the role of DOE in aeolian sand protection.

Effect of bridge height on airflow and aeolian sand flux near surface along the Qinghai-Tibet Railway, China.

In this work, we studied the near-surface flow field structure of railway bridges with different heights through field investigation and wind tunnel simulation experiments. Meanwhile, we simulated the distribution of sand accumulation around a bridge via CFD software based on the sand accumulation around the Basuoqu bridge in the Cuona Lake section of the Qinghai-Tibet Railway. Results show that the sand around this railway bridge is mainly from the lake sediment on the west side of the railway and the weathered detritus on the east side.

Direct validation of dune instability theory.

Modern dune fields are valuable sources of information for the large-scale analysis of terrestrial and planetary environments and atmospheres, but their study relies on understanding the small-scale dynamics that constantly generate new dunes and reshape older ones. Here, we designed a landscape-scale experiment at the edge of the Gobi desert, China, to quantify the development of incipient dunes under the natural action of winds. High-resolution topographic data documenting 42 mo of bedform dynamics are examined to provide a spectral analysis of dune pattern formation.

Characteristics of Desertification and Short-Term Effectiveness of Differing Treatments on Shifting Sand Dune Stabilization in an Alpine Rangeland.

Rangeland desertification is one of the most serious problems threatening the ecological environment and socio-economic development on the eastern Qinghai-Tibet Plateau in China. To combat desertification and reduce its adverse effects, some strategies have been undertaken to stabilize the mobile sand dunes and restore the desertified land. In this study, rangeland desertification with a gradient degree of none, light, medium, severe and extreme was assessed, and short-term effectiveness of different treatments on stabilizing the shifting sand dunes was evaluated by monitoring selected vegetation and soil properties.

Local Circulation Maintains the Coexistence of Lake-dune Pattern in the Badain Jaran Desert.

Previous studies proposed various hypotheses to the formation of the mega-dunes and water recharge of the lakes in the Badain Jaran Desert but left the coexistence of lake-dune pattern unsolved. This research found that the local circulation, generated from the differences of thermodynamic properties and the unique landscape settings between lakes and mega-dunes, can be applied to interpret the pattern.