The Contrast Study On Protect Effect About Two Kinds Of Populus Shelterbelts In Hetao Irrigated District

Parallel contrast study was done on the protect effect of Populus popular's and Populus alba L.Var.pyramidalis shelterbelt with the same age and structure in Hetao Irrigated District. The main conclusion that was got through analyzing for their protect effect is: two kinds of shelterbelt both can reduce the wind speed effectively, the 3H point of the protect sheltebelt leeward have the best protect effect , Populus popular's shelterbelt superior to Populus alba L.Var.pyramidalis shelterbelt in windproof efficiency. Two shelterbelt both can improve the climatic conditions effectively, Populus popular's shelterbelt superior to Populus alba L.Var.pyramidalis shelterbelt in falling the air temperature and improving the air humidity etc. Two shelterbelt both can reduce the water evaporating and the soil evaporating effectively, Populus popular's can reduce 12.9% in water evaporating and 41.72% in soil evaporating, while Populus alba L.Var.pyramidalis reduce 7.8% and 35.04% separately in the observation days, Populus popular's shelterbelt superior to Populus alba L.Var.pyramidalis' in reducing evaporation. Contrast analysis was done on water-saving function of two shelterbelt, the result is as following: Populus alba L.Var.pyramidalis shelterbelt superior to Populus popular's shelterbelt on water-saving function, the saving water amount of Populus popular's is 198.6 m3/hm2 averagely, Populus alba L.Var.pyramidalis' is 168.5 m3/hm2 averagely.