河西走廊的干热风是一种高温、低湿和吹偏东风的特殊大气干旱现象。它主要危害春小麦,有的年份对冬小麦和棉花的危害也较重。在六月中下旬至七月上中旬小麦开花—乳熟期常常出现干热风天气,使西起敦煌东至景太的十四个县(市)所种植的近四百万亩春小麦,约有三分之二以上遭到不同程度的危害,一般年份减产5—10％,严重者可达20％以上。一、干热风的时间变化 Hexi Corridor, the hot and dry wind is a high temperature, low humidity and wind blowing a special phenomenon of atmospheric drought. It mainly harms spring wheat, and in some years, it harms winter wheat and cotton. In mid-June to mid-July, wheat flowering and milking usually occur during the flowering and milking phases, leaving nearly 4 million mu of spring wheat planted in 14 counties (cities) in the east of Dunhuang and Jingtai, Two-thirds or more of them have been harmed to varying degrees. In general, production will be cut by 5-10% and in severe cases by more than 20%. First, the dry wind time changes