玉门镇西戈壁铁路防沙林带林沿积沙及其防治试验

本文是玉门镇西戈壁铁路防沙林带林沿积沙防治试验的总结。研究当地风沙与林沿积沙特征,制定外堵西风口以断沙源、内引东风以退积沙的措施。经过1971—1977年的试验,证实效果良好。

THE ACCUMULATION OF SAND AND ITS PREVENTION AND CURE ALONG THE FRONT OF SHELTER BELT OF THE RAILWAY ON GOBI WEST OF YUMEN TOWN

This paper is a summary of the accumulation of sand along the front of shelter belt of the railway and its experiment of prevention and cure.It is a region from southeast K905 to northwest K909 of the railway on gobi west of Yumen town. It is located in the alternative region of the west and east wind, but the west wind is stronger and it prevails longer. On the left of the railway there is broad gobi with soil, and at the far west there is the former wood belt from south to north but it breaks and leaves a gap toward the west (west wind gap) near the railway. Outside the gap is a mobile survived mound of soil erosion and a sand drift. Therefore, the sand accumulates only along the wood belt at the left front of the railway, and the western section is more serious than the eastern one. The east wind can restrict the sand accumulation but can't stop its intrusion to the wood belt.The accumulation of sand is caused by the sand wind stopped by the wood, and the wind velocity near the surface decreases fast. However, to keep the wood growing this wood belt must be often irrigated. The sand accumulation makes great damages, because it destroys the shelter belt and approaches to the railway, a threast to the trasportation. So it must be prevented and cured, and emphsis must be put on the sand accumulation of the western section. The plan of prevention and cure is as a whole made of two steps, that is to block the west gap and to withdraw the sand.The former step is to keep the west section of this belt in good condition to extend it to K900-500, and to build two wood belts to block the west gap. Before the wood belt on the west side must be established on area of solid sand barrier, ditch and dike of sand prevention, and the bush belt. After it is established, it prevents the sand intrusion to the wood belt. Unfortunately, according to the investigation of 1976, this prevention and protection area has been detroyed, and the sand drift has instruded to the wood belt. It is necessary to reestablish the area of prevention and protection.