直立植被抗风蚀性能的测试与评价

The Measure and Evaluation on the Anti-wind Erosion Properties of Standing Vegetation

借助移动式风蚀风洞,对直立植被的抗风蚀性能进行了原位测试。试验结果表明:在一定风速下,地表的空气动力学粗糙度随植被高度的增加呈指数增加,且随着植被高度的增加,作用于植被上的剪切力增加,而作用于地表的剪切力减少;一定高度的植被可有效地截留风沙流,农田地表的风蚀量随风速的增加呈指数增加。

The anti-wind erosion properties of standing vegetation were measured in its original position by means of the movable wind erosion tunnel. It was found that the aerodynamic roughness length increased with the vegetation height by exponential function at the constant wind velocity. At the same time, the shearing force upon standing vegetation increased and upon bare soil surface decreased with the increase of the height of vegetation. Some certain height vegetation can prevent from wind-sand flow efficiently. The amount of wind erosion increased with the increase of wind velocity by exponential function.