沙丘移动速度的观测与计算

在沙漠地区研究沙丘上风沙输运和估算沙丘移动速度对防治沙害有实际意义。文献1,2均给出了计算沙丘移动速度的公式,但必须知道相应的输沙率。由于输沙率和当地风速有关而沿沙丘脊线不同高度处有不同的风速,如何把沙丘上各点的风速与受沙丘扰动的“来流”风速关联起来就成为关键问题。本文对5个不同高度沙丘上的风速和输沙率进行多次观测、在详细分析所得数据的基础上给出了风速之间的关联和计算沙丘移动速度的普遍公式,并与实测结果作了比较。

MEASUREMENT AND COMPUTATION OF DESERT DUNE MOVEMENT SPEED

There are various desert dunes in a desert area, all of them move und-er action of wind force. It is important for preventing sand calamities toresearch wind-sand transport on a desrt dune and to estimate the movementspeed of the desert dune. A lot of outdoor measurement are made. Measurement suggests that the transport rate of sand on a desert dune equals whichon a plane desert provided the wind speed and sand diameter are same eachother. Based on the analyses of observation data the relationship between t-he wind sqeed on a desert dune and the free wind speed is given, also theequation to compute the movement speed of desert dune. Tbe results fromcomputation are agreeable very well to that from outdoor measurement