Author(s): Naoko Kohashi
Linked Author(s):
Keywords: Bottom Roughness; Residual Current; Substance Transport; Water Pollution
Abstract: Nowadays there are some chronic serious environmental problems, such as eutrophication, blue tide and so on, in a complicated coastal zone and a semienclosed bay, because the water exchange between an inner bay and an outer sea is weak compared with the supply of contaminant. Under this situation, a method to improve the water quality by 3-dimensional unsymmetrical small structures have been proposed by Komatsu et al. (1997). Here, the term of" Bottom Roughness" means this artificial structure set up on the sea bottom. In this paper, a concept and a summary of this method are described, and then its effect is examined by laboratory experiments and numerical simulations. From these results, it becomes clear that: 1) the substance transport can be intensified by using Bottom Roughness, 2) this method has a ability to create and control a residual flow pattern. Consequently, it is found that this method can make the water quality in a sea area better with the help of only natural tidal energy.
Year: 1999