砾石覆盖防风蚀风洞实验

Wind Tunnel Experiments on Gravel Mulch Restraining Wind Erosion

利用风洞实验开展了2 cm粒径砾石覆盖防风蚀效果研究。实验结果表明:砾石覆盖的存在可大幅降低沙床输沙率;同一风速下,输沙率随覆盖度的增加而降低,砾石覆盖率高于35%时床面不发生明显风蚀;同一砾石覆盖度下,输沙率随风速的增加而增加,风速超过18 m/s时输沙率迅速增加。采用风蚀防护率指标评价了砾石覆盖的防风蚀效果,当覆盖度不低于35%、风速不超过26 m/s时,风蚀防护率均大于90%。研究结果对采用砾石覆盖进行某数百平方公里的场地防风固沙工程设计具有参考价值。

Anti-wind erosion experiments of 2 cm gravel mulch were done by wind tunnel. Experimental results showed that duo to the presence of gravel mulch, the rate of sand transporting on bed was significantly reduced; in the same wind speed, the sand transport rate decreased with coverage rate increasing, and the bed would not be obvious eroded with coverage rate above 35%. Under the same gravel coverage rate, the sand transport rate increased with wind speed increasing, and the sand transport rate rapidly increased when the speed exceeded 18 m/s. The rate of erosion protection was used to evaluate the effect of erosion protection of gravel mulch, under the conditions of coverage rate no less than 30% and wind speed not less than 26 m/s, the rates of erosion protection were higher than 90%. The study is useful for fixing sand in a hundreds of square kilometers of venue with gravel mulch.