风沙区马铃薯高垄栽培技术的防风阻沙效果

Study on Wind Prevention and Sand Resistance of Potato Cultivation Technique in Sandstorm Area

为了探讨高垄栽培技术防风阻沙效果,对高垄栽培下的马铃薯耕地的上风向、耕地上边缘、耕地中心、耕地下边缘、下风向的近地层风流场和输沙通量等风沙运动指标进行监测与分析。结果表明:气流自上风向至下风向运动过程中,受高垄栽培技术的影响,风速降低幅度、空气动力学粗糙度、摩阻风速均呈现先增加后降低的变化规律,其中在耕地下边缘处达到最大,其10,30,50,100,200 cm高度的防风效能分别为34.96%,46.59%,38.37%,26.68%,18.31%,空气动力学粗糙度与摩阻风速分别为2.15 cm和0.91 m/s,分别是上风向的4.56,1.19倍;垂直方向看,高垄栽培技术对于30 cm高度的风速削弱作用最为明显。风沙流自上风向至下风向运输过程中,其总单宽输沙率呈现先减小后增大的变化规律,在耕地下边缘的总单宽输沙率降至最低,为0.02 g/(cm·min),较上风向减小207.97倍,并且在耕地内部时,风沙流结构发生变异,各层输沙率不再满足指数递减规律。研究结果可为高垄栽培技术在防风阻沙应用中提供一定的理论依据。

This study monitored and analyzed the wind and sand movement indexes of potato cultivated land under high ridge cultivation technology,such as upwind wind field,upper edge of cultivated land,center of cultivated land,lower edge of cultivated land,and downwind wind flow field.Results showed that the airflow from the upwind to the downwind during the movement was influenced by the high ridge cultivation techniques.The wind speed reduction,aerodynamic roughness and friction wind speed increased first and then decreased,which reached the maximum at the lower edge of the cultivated land.The wind prevention efficiency at the 10,30,50,100,200 cm height were 34.96%,46.59%,38.37%,26.68%,18.31%respectively.The aerodynamic roughness and friction wind speed were 2.15 cm and 0.91 m/s,which were 4.56 and 1.19 times that of the upwind.From the vertical direction,high ridge cultivation technique had the most obvious weakening effect on wind speed at 30 cm height.During the sand flow from the upwind to the downwind,its total sediment discharge per unit width decreased first and then decreased,with the lowest value in the lower edge of the cultivated land,0.02 g/(cm·min),reduced by 207.97 times than the upwind.Within the cultivated land,sand flow structure changed,the sediment rates in different layers no longer met the law of exponential decline.This study could provide some theoretical basis for the application of high ridge cultivation technique in the wind prevention and sand resistance.