甘肃张掖地处河西走廊中部,气候干燥,雨量稀少,年降雨量仅120毫米,而蒸发量大。境内公路穿越高寒山区、戈壁沙漠和沼泽碱滩,公路绿化的自然条件很差;终年积雪的高山和荒原自不必说绿化,即便是在农业灌溉的绿洲之内,由于要坚持不与农田争水的关系,公路绿化也是相当困难的。因此,自建国初期到六十年代,我区的公路 Gansu Zhangye is located in the central Hexi Corridor, dry climate, scarce rainfall, annual rainfall of only 120 mm, while the evaporation. The domestic roads cross the alpine mountainous areas, the Gobi Desert and the swampy alluvial beaches, and the natural conditions of highway greening are poor. The snow-capped mountains and wastelands have no need to say afforestation year after year. Even within the oasis of agricultural irrigation, Water relations, highway greening is quite difficult. Therefore, from the early Republic to the sixties, my area of ​​highway