Hong, I.; Kim, J.S.; Kim, K.H.; Shin, H.S., and Jeon, H.S. 2018. Analysis of physical habitat change for target fish induced by extended floodplain. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 86–90. Coconut Creek (Florida), ISSN 0749-0208.

Flood protection structures such as levees and dams are being built continuously to prevent floods and they cause many rivers to lose inundated river areas. These losses slow down the natural development process and also reduce the weighted usable area of fish. In particular, fish requiring periodic floods and floodplains are seriously affected by flow regulation and floodplain reduction. Therefore many species of fish have gone extinct due to environmental changes and instability of river ecosystems. In order to protect and maintain the habitat environment of fish in aquatic ecosystem, proper habitat of fish must be guaranteed. One of the ways to ensure the proper habitat of fish is to restore the floodplain area. Restoration of floodplain offers many benefits to several species. The River2D model was used to simulate habitat of Pseudopungtungia nigra with life stage before and after restoration on the Mankyung River. As a result of WUA calculation which is an important index when estimating the optimum flow rate, it is found that after three kinds of restoration scenarios are more effective than before restoration. In case of old bypass channel restoration, the WUA value shows that the largest restoration effect at 20.0% in spawning and 39.5% in juvenile stage. Unlike the previous result, restoration effect of backswamp restoration was largest at 85.3% in adult stage. Based on these results, it is necessary to secure proper habitat to protect and maintain the fish habitat environment, and it is also considered that the effect on the physical habitat with life stage should be fully examined.