본 연구에서는 확률밀도함수의 서식처 적합도 지수를 사용하여 도심하천구간과 자연하천구간에서 유량점증방법론(Instream flow Incremental Methodology, IFIM)을 토대로 피라미 서식처의 생태유량을 모의하였다. 이와 같은 방법을 적용하기 위하여 본 연구에서는 PHABSIM 모형을 사용하였다. 본 연구에서는 서식처 적합도 지수(Kang, 2010)를 기초로 확률밀도함수의 매개변수를 조정하여 확률밀도함수의 서식처 적합도 지수를 개발하여 생태유량을 분석하였다. 그 결과, 도심하천구간에서는 정규분포가 자연하천구간에서는 2변수 log-pearson 분포가 Kang (2010)의 생태유량에 가장 근접하는 경향을 보였다. 확률밀도함수에 의한 서식처 적합도 지수와 하천구간별로 생태유량을 모의하여 확률론적 방법을 적용한 생태유량 산정기법을 제안하였다.

In this study, a comprehensive field monitoring was conducted to understand habitat conditions of fish species in up and downstream of Hoengseong Dam. Based on the monitoring data, riverine health conditions such as composition ratio of fish species, bio-diversity (dominance index, diversity, evenness and richness), index of biological integrity (IBI) and qualitative habitat evaluation index (QHEI) were assessed, and optimal ecological flowrates (OEF) were estimated using the habitat suitability indexes (HSI) established for three fish species Coreoleuciscus splendidus, Pungtungia herzi and Microphysogobio longidorsalis selected as icon species using the physical habitat simulation system (PHABSIM). The total number of species sampled was 20 species, and two species of Zacco platypus (30.4%) and C. splendidus (20.9%) dominated the fish community. As a result, it was revealed that IBI and QHEI values decreased from upstream to downstream along the river. The estimated IBI value ranged from 24 to 36 with average being 30.9 out of 50, rendering the site ecologically fair to good health conditions. HSI for C. splendidus were determined according to three different month in terms of season: Spring (April), Summer (August) and Autumn (October). HSI for flow velocity were estimated at 0.7 to 0.8 m/s for the Spring, 0.5 to 1.0 m/s for the Summer and 0.8 to 0.9 m/s for the Autumn. HSI for water depth were estimated at 0.3 to 0.5 m for the Spring; 0.3 to 0.5 m for the Summer; and 0.3 to 0.4 m for the Autumn. OEF was estimated at 4.2 and 6.5 m3/s for the Spring and Autumn, and 12.0 m3/s for the Summer. Overall, it was concluded that the Hoengseong Dam has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.

금강수계중 용담댐하류 앞섬 지점에서 생태유량을 산정하기 위한 생태 모니터링을 실시하여 어류종별 서식환경 특성조사를 포괄적으로 실시하였다. 이를 바탕으로 어류상, 상대풍부도 및 생물다양도 분석 등을 포함한 하천의 건강성 평가를 실시하고, 쉬리, 피라미 및 감돌고기 등에 대하여 작성한 서식처적합도 지수(HSI)와 물리적 서식처 모의시스템(PHABSIM)을 이용한 최적 생태유량을 산정하였다. 본 지점에서 채집된 종수는 20종이였으며, 우점종은 쉬리(22.4%

This study was focused on estimating instream flow, and its optimal alternative for securing the required total amount of instream flow was also researched in order to restore ecosystems and riverine aesthetics of the Mugeo Stream, the first tributary of the Taewha River flowing through the center of Ulsan. In this study the hydraulic and hydrologic conditions and water quality were investigated at specific channel reaches and representative stations of the Mugeo Stream to determine a proper estimate of instream flow. And riverine functions, such as the minimum flow, water quality conservation, fish habitat, and recreation, were considered to restore the environmental functions of the stream. As a result, the total amount of 11,500㎥/day was set as the target instream flow for the Mugeo Stream. It was chosen as the optimal alternative for securing the total external supply of 10,000㎥/day which have to be transfered from the riverbed flow diverted through the Taewha Main river at upstream of Samho bridge. The water quality throughout the Mugeo Stream channels will be improved considerably to 3-4 mg/l of BOD standard if the target instream flow is supplied and sewage is intercepted by the sanitary sewage system.

금번 연구는 낙동강 유역의 영강, 위천, 회천, 거창위천, 청도천, 단장천에서 산란기와 성어기에 어류의 서식과 수심, 유속, 하상재료 등 수리학적 특성에 관한 자연과학과 공학의 학제간 상호 연계조사를 시행하였으며, 어종별(피라미와 갈겨니), 성장단계별(산란기와 성어기), 서식처조건별(수심, 유속과 하상재료) 어류 서식 적합도 기준을 작성하였다. 유지유량 증분법 개념의 물리적 서식처 모의시스템을 적용하여, 낙동강 유역의 주요 하천에서 어류서식에 적합한 유