The Role of Dams for River Ecosystem Restoration and Managing Environmental drought

In this study, an environmental drought monitoring method was developed in the river ecosystem considering the fish habitat, and the role of the dam on the restoration of the river aquatic ecosystem and environmental drought management is analyzed. To analyze the flow regime, fish habitat, and environmental flow change before and after dam construction, a multidisciplinary approach linking ecology, hydrology, hydraulics, and GIS was applied. The Ecological Drought Index for Fish Habitat (ECODI fh) was developed using the results of calculating the ecological flow required to secure the habitat of the target fish species. As a result of comparing SPI, which is a meteorological drought index calculated by applying precipitation in Korea's Gam river basin, and ECODI_fh based on fish habitat, the severity of the ecological drought was similar in the meteorological drought period (2008-2009) before dam construction. However, after the dam construction, it was found that the ecological drought situation was maintained for a considerable period of time due to the supply of environmental flow from the dam even during the meteorological drought period (2014-2015). Using ECODI_fh proposed in this study, the damage caused by drought in the river ecosystem can be quantitatively evaluated in connection with the environmental flow, and it is judged that real-time monitoring of ecological drought is possible. In addition, it is expected that the dam operation method during the drought period to properly respond to the environmental drought can be technically presented.