关键词: 河西走廊, 沙尘暴成因, 防护体系

Abstract: A Catastrophic sandstorm occurred at 14:00-20:00 on May 5,1993. The height of dust cloud ranged between 300-400m,with a maximum height reaching 700m. The maximum velocity of the sandstorm was 76km/hr,instantaneous wind speed 20m/s or more,maximum wind speed 34m/s. This sandstorm caused great damages to industrial and agricultural production, the direct economic loss amounted to 236 million yuan. According to survey and analytical data in typical regions, hazards are mainly occurred in the old oases and newly-opened irrigation regions, where there is no perfect shelterbelt. The main countermeasures to control sandstorm include establishment of psammophile vegetation,large-scale sandbreak forest and farmland shelterbelt as well as protection of existing vegetation.