利用PAM防治松散扰动沙土风蚀效果的风洞试验研究

    Wind tunnel experiment on the impacts of polyacrylamide on wind erosion of loosen soil materials

    • 摘要: 翻耕农地和建设工地的扰动松散土是沙尘的重要来源。防止扰动土风蚀是保护生态环境的重要内容。该研究通过室内风洞模拟试验,研究了PAM对于提高松散扰动土起动风速、防止风蚀的效果。试验分别采用0°、10°、20°、30°不同的吹角,地表处理为:喷施PAM(用量分别为0.5,1,2,4 g/m2)、喷施清水和未加处理的自然松散扰动(沙)土。试验结果表明:通过表面喷洒PAM溶液可以显著地提高松散扰动土的起动风速,达到控制风蚀的目的;仅喷洒清水处理也可以在一定程度上提高沙尘的起动风速,但其效果甚微;如果松散(沙)土喷施PAM的表面不被扰动(无裂纹),用于松散土风蚀防治时PAM用量控制在1 g/m2以上就可以有效防止风蚀发生,试样经受风速为14 m/s左右的大风、历时30 min而未产生风蚀。

       

      Abstract: The disturbed and loosen soils in cultivated farmlands and onconstruction sites are known to be amongst the main sources responsible forduststorms. Controlling wind erosion of the disturbed soils is of great importancefor environmental protection. Wind tunnel experiments were conducted to study the impacts of Polyacrylamide(PAM) on the threshold wind velocity in wind erosioncontrol, and wind erosion prevention. The experiments involved four different wind approaching slopes: 0°, 10°, 20° and 30°, six soil surface treatments: 0(untreated, control), 0.5, 1, 2 and 4 g/m2 of PAM, as well as surface water application. The experimental results indicate that PAM application to soil surfacecan dramatically increase the threshold wind velocity which means a good control of soil wind erosion. The threshold wind velocities of soil samples treated withwater were also higher than those of untreated samples but the degree was very limited. If the surface treated with of PAM of more than 1 g/m2 with no disturbs(or no crackles on the surface), the loosen soil can withstand a strong wind of 14 m/s for more than 30 min without wind erosion.

       

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