| 摘要 |
<p>PROBLEM TO BE SOLVED: To cultivate microbes in a layer in which pebbles (cobble stones or the like) are stuffed in the voids between recesses in the joint of the upper part and the bottom formed by continuously laid purifying and protecting river bed blocks and the adjacent recesses to improve the quality of water by means of the biofilm and improve highly advanced functional effects in culture, protection, recovery, etc., for fish and shellfish and aquatic lives. SOLUTION: In purifying and protecting river bed blocks for a water stream, recesses 6 are formed in the joints 4 having I-shaped sections at the front and side faces and connecting the square bottom 2 and the smaller square top 3 than the bottom and natural stones are put on the upper face of the top 3. And further, pebbles are stuffed in the voids 7 formed by the recesses of the joints of the blocks 1 parallelly laid and adjacently formed.</p> |
