J Korean Soc Environ Eng. 2016; 38(2): 47-55.
Published online 2016 February 29.
Estimation of Ecological Flow and Habitat Suitability Index at Jeonju-Cheon Upstream
Department of Civil Engineering, Chonbuk National University
Received 2015 December 02; Accepted 2016 February 02.
ABSTRACT
In this study, WUA (Weighted Usable Area) based on the Instream Flow Incremental Methodology (IFIM) was calculated to determine ecological flow at JeonJu-Cheon by using River2D model. To calibrate River2D, simulation results for low flow conditions of River2D were compared with calibrated HEC-RAS simulation results and the optimum parameters were determined. The results were RMSE (0.18), NSE (0.71) and coefficient of determination (0.78) for velocity and RMSE (0.02), NSE (0.71), coefficient of determination (0.73) for water depth. The result shows that the model successfully simulates the water flows. A selected target fish species to build the habitat suitability index were composed of Zaccoplatypus and Coreoleuciscus splendidus. These species showed the highest occurrences over the past decade in f ish monitoring. Also, The WUA-Discharge curve was calculated with the suitability index in a medium flow conditions. From the result, WUA is changed according to flowrate. In the flowrate-WUA/A graph, ecological flow can be determined at 1.8~2.0 m3/s for Zaccoplatypus 2.0 m3/s and Coreoleuciscus splendidus 1.8 m3/s at JeonJu-Cheon upstream. When compared with flow-duration analysis, it is demonstrative that simulation results fitted ecological flow considering quantity of available habitat for each fish species.
Keywords :
IFIM (Instream Flow Incremental Methodology), WUA (Weighted Usable Area), HSI, River2D, Ecological Flow
