PHABSIM을 이용한 복하천 하류 구간의 피라미 생애주기별 물리적 서식처 평가

Abstract

The objectives of this study were to assess physical habitat suitability of fish species for different life cycle stages and to suggest appropriate ecologicalstream flows in a Bokha downstream reach. A dominant species of Zacco platypus was selected as the study fish of which three stages of spawning,juvenile and adult in life cycle were considered into assessment. The stream hydraulic environment was calibrated with HEC-RAS before the PHABSIMsimulation. The hydraulics of flow velocity and depth were used to estimate Weighted Usable Area (WUA) by multiplying respective habitat suitabilityindices with stream area. Overall the WUAs tend to be great in gentle slopes with relatively shallow water depth regions. Maximum WUAs, ie,candidate for ecological flow rates were 1 m3/s, 7 m3/s and 8 m3/s for the respective spawning, juvenile and adult stages of Zacco platypus. Sincethe ecological flow rates for juvenile and adult stages appeared to be is greater than the abundant flow rate (3.67 m3/s) for the study reach, additionalwater supply may be needed but should be cautious to avoid the spawning period of Apr through May from the stream water management perspective.