Abstract
Several topics on commonality and dissimilarity between ecology and civil engineering in rivers and streams of Japan were provided. Both contain the fields of spatial sciences. Thus, habitat becomes a principle importance for both sciences. In river and stream ecosystems, habitat produces species richness, which enhances the biodiversity within river ecosystem. I also revised a check-sheet of microhabitats which is conformed by three spatial layers: channel center and margin, riffle-pool sequences, and habitat elements.
