A study on the development of environmental-ecological flow standards in Nam river watershed

Accelerating climate change and artificial structures such as dams threaten the quality and quantity of water environments on rivers. Recently, issue for the health of these ecosystems is emerging in Korea. Comparing to study focused only on the amount of water in the past, interest in the ecological function of rivers is increasing today. The ecological function of a river plays an important role in maintaining the environmental health of the river by maintaining the habitat conditions of the ecosystem in the river. In general, assessments of optimal or minimum flow rates required to preserve ecosystem function have been performed by habitat- based models that define the relationship between stream flow and habitat availability for fish. In this study, a study on the environmental- ecological flow of the Nam River in Korea was conducted with physical habitat simulation using flow data from 2010 to 2020. The target fish species were platypus, platypus, Odontobutis platycephala, and Squalidus chankaensis tsuchigae, which were selected based on field monitoring. Fish habitats were evaluated at Geumsan Bridge upstream of Namgang and Jeongamdaegyo Bridge downstream of Namgang respectively. The environmental- ecological flow results for the platypus, Odontobutis platycephala, and Squalidus chankaensis tsuchigae are as follows: 3.1, 28.1, and 41.3 CMS in. Geumsan Bridg, respectively, and 19.6, 4.9, and 24.5 CMS, in Jeongam Bridge, respectively. It is expected that this study can be used as a guideline for river restoration or environmental flow maintenance in the future.