PHABSIM을 이용한 반변천 하천생태유량 산정- 피라미, 참몰개를 대상으로 -

Abstract

The objective of this study was to estimate an optimum ecological flow rate in the Banbyeon stream based on the two representative fish species.Hydraulic stream environment was simulated with HEC-RAS for two water flow regimes and used for the PHABSIM hydraulic simulation. A dominantspecies of Zacco platypus and an endemic species of Squalidus chankaensis tsuchigae were selected as the representative fishes whose habitat conditionswere evaluated for the spawning and adult stages. Weighted usable area (WUA) was estimated based on habitat suitability index (HSI) and PHABSIMhabitat simulation. Overall deep water zone in the stream demonstrated greater WUA which implies better habitat status. The estimated WUA for Zaccoplatypus as the dominant species was about five times greater than Squalidus chankaensis tsuchigae at the stream flow of 12 m³/s. The optimumecological flow rates were 15 m³/s and 25 m³/s for the respective spawning and adult stages of Zacco platypus, while 5 m³/s was estimated for boththe life cycles of Squalidus chankaensis tsuchigae. Assuming that the dominant species may survive better in wider flow regimes, the optimumecological flow rate should be determined rater based on the endemic species and flow rate of 5 m³/s was suggested for the Banbyeon stream.