Controlling fine wind-blown sand on beaches

在美国和荷兰等一些国家，海滩滋养现在是海岸保护的主要选择，在其他国家，特别是在西欧和日本，它正越来越多地被使用。填充材料必须取自海上采掘区，这种材料的直径通常很小。这样的细沙很容易被风吹走。人们对细沙的风沙输送知之甚少。此外，在平坦的沙面上输送的风沙通常会集中在靠近地面的一层。然而，相当数量的风沙可能会穿过几米高的防风林，并被输送到内陆。目前尚无全面的理论来描述这一现象。本研究的目的是解决这一问题。本研究针对细沙提出了三个子主题：1)建立细沙的输沙率公式；2)解释和估计穿越高风黑并向内陆输送的沙粒现象；3)制定小障碍物周围风沙局部堆积的对策。期末报告给出了第一和第二主题的研究成果。第三个主题正在研究中，结果将在不久的将来公布。

Beach nourishment is now the principal option for shore protection in some countries such as the USA and The Netherlands, and it is being increasingly employed in other countries, particularly in Western Europe and Japan. Fill material must be taken from offshore borrow areas and this material is usually small in diameter. Such fine sand is easily transported by the wind. There is little knowledge about wind-blown transport of fine sand. In addition, wind-blown sand that is transported over a flat sand surface is normally concentrated to a layer near the surface. However, considerable amount of wind-blown sand may cross over wind-breaks that are several meters high and be transported inland. At present, there is no comprehensive theory to describe this phenomenon.The purpose of this study is to solve the problems.Three sub three themes are stated in this study concerned with the fine sand ;1)to establish the sand transport rate formula for fine sand,2)to explain the phenomenon and estimate sand that cross over the high wind-blacks and transported inland,3)to develop countermeasures for the local accumulation of blown sand around small obstacles.Research results concerned the theme first and second are given in the final report. Third theme is under research and results will be published in near future.