2006 年 12 巻 p. 437-442
A natural deficit part on a groundsel was found at the Oyanagawa river that is a branch of the Fuji river in Yamanashi Prefecture, Japan. It was observed that the deficit part was used as a transportation route for aquatic animals as well as that the groundsel still remained the disaster prevention function. Therefore, the local government of Yamanashi Prefecture decided to conduct slitting works of groundsels at the same river tentatively. After the slitting work, habitat for aquatic animals has changed by river bad variation and sediment transport. The follow-up investigation on the change is carried out from August 2003. This paper reports these results of the investigation in order to develop a rational basic examination method for similar river works.