The Qinghai-Tibet Railway(QTR) passes through 281 km of sandy land, 11.07 km of which causes serious sand damage to the railway and thus, the control of blown sand is important for the safe operation of the railway. C...The Qinghai-Tibet Railway(QTR) passes through 281 km of sandy land, 11.07 km of which causes serious sand damage to the railway and thus, the control of blown sand is important for the safe operation of the railway. Construction of the railway and sand prevention system greatly changed the blown sand transport of the primary surface. Effective and feasible sand-control measures include stone checkerboard barriers(SCBs), sand fences(SFs), and gravel coverings. This study simulated the embankments, SCBs and SFs of the QTR in a wind tunnel, and analyzed their respective wind profile, sand deposition, and sand-blocking rate(SBR) in conjunction with field data, aiming at studying the influence of Golmud-Lhasa section of the QTR and sand prevention system on blown sand transport. The results of wind tunnel experiments showed that wind speed increased by 67.7%–77.3% at the upwind shoulder of the embankment and decreased by 50.0%–83.3% at upwind foot of embankment. Wind speed decreased by 50.0%–100.0% after passing through the first SF, and 72.2%–100.0% after the first row of stones within the first SCB grid. In the experiment of sand deposition, the higher the wind speed, the lower the SBR of SCB and SF. From field investigation, the amount of sand blocked by the four SFs decreased exponentially and its SBR was about 50.0%. By contrast, SCB could only block lower amounts of sand, but had a higher SBR(96.7%) than SF. Although, results show that SFs and SCBs along the Golmud-Lhasa section of the QTR provide an obvious sand blocking effect, they lead to the deposition of a large amount of sand, which forms artificial dunes and becomes a new source of sand damage.展开更多
No simple solution to flood prevention is accessible. This research provides a brief summary of the hydrologic and hydraulic methodology that can be used to develop specific details that integrated the flood informati...No simple solution to flood prevention is accessible. This research provides a brief summary of the hydrologic and hydraulic methodology that can be used to develop specific details that integrated the flood information tool. It permits rapid analysis of a wide variety of stream discharge data and topographic mapping to avoid the flood hazard over entire floodplain boundaries. This paper focuses on the water floodplain hazard in Wadi Asla-Jaddah-Saudi Arabia. The most common type of rainfall in the study area is that accompanied by thunderstorms, which usually fall during the winter season as well as in the spring. The primarily evaluation of this problem and the solution is contemplate. The more essential and ＂doable＂ elements of a solutions and recommendations are discussed in this research.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.40930741)National Basic Research Program of China(No.2012CB026105)
文摘The Qinghai-Tibet Railway(QTR) passes through 281 km of sandy land, 11.07 km of which causes serious sand damage to the railway and thus, the control of blown sand is important for the safe operation of the railway. Construction of the railway and sand prevention system greatly changed the blown sand transport of the primary surface. Effective and feasible sand-control measures include stone checkerboard barriers(SCBs), sand fences(SFs), and gravel coverings. This study simulated the embankments, SCBs and SFs of the QTR in a wind tunnel, and analyzed their respective wind profile, sand deposition, and sand-blocking rate(SBR) in conjunction with field data, aiming at studying the influence of Golmud-Lhasa section of the QTR and sand prevention system on blown sand transport. The results of wind tunnel experiments showed that wind speed increased by 67.7%–77.3% at the upwind shoulder of the embankment and decreased by 50.0%–83.3% at upwind foot of embankment. Wind speed decreased by 50.0%–100.0% after passing through the first SF, and 72.2%–100.0% after the first row of stones within the first SCB grid. In the experiment of sand deposition, the higher the wind speed, the lower the SBR of SCB and SF. From field investigation, the amount of sand blocked by the four SFs decreased exponentially and its SBR was about 50.0%. By contrast, SCB could only block lower amounts of sand, but had a higher SBR(96.7%) than SF. Although, results show that SFs and SCBs along the Golmud-Lhasa section of the QTR provide an obvious sand blocking effect, they lead to the deposition of a large amount of sand, which forms artificial dunes and becomes a new source of sand damage.
文摘No simple solution to flood prevention is accessible. This research provides a brief summary of the hydrologic and hydraulic methodology that can be used to develop specific details that integrated the flood information tool. It permits rapid analysis of a wide variety of stream discharge data and topographic mapping to avoid the flood hazard over entire floodplain boundaries. This paper focuses on the water floodplain hazard in Wadi Asla-Jaddah-Saudi Arabia. The most common type of rainfall in the study area is that accompanied by thunderstorms, which usually fall during the winter season as well as in the spring. The primarily evaluation of this problem and the solution is contemplate. The more essential and ＂doable＂ elements of a solutions and recommendations are discussed in this research.
