Author(s): Jung Min Kim; Young Do Kim; Siwan Ryu; Jae Hyeon Park; Won Je Lee
Linked Author(s):
Keywords: IFIM; PHABSIM; QUAL2E; Ecological flow recommendation
Abstract: Hydraulic structures such as a dam, a weir and a water gate affect on the flow depth, velocity, bed topology, water quality and so on, so that the hydraulic structures may affect on the water environment for plants and aquatic lives in and around rivers. Therefore, before construction of such hydraulic structures, it is necessary to conduct the environmental assessment. To recommend ecological flow for major tributaries in Changwon Stream basin, the Instream Flow Incremental Methodology (IFIM) have been applied. In particular physical habitat simulation using PHABSIM have been selected for microhabitat variables and QUAL2E model have been used to implement the opitimal environmental flow. The PHABSIM technique enables the quantitative prediction of suitable physical habitat in a river reach for chosen species and lifestages under different river flow scenarios, based on field measurements, hydraulic calibration, and species physical habitat preferences (depth, velocity, and substrate). The PHABSIM model was applied to adjacent straight trapezoidal and highly sinuous reaches in a third order agricultural stream in East-Central Illinois. A 30-Year flow record for each reach. Supplementing PHABSIM analysis, detailed surveys provided planamitric maps of each reach, and regular fish sampling both supported the selection of species modeled with PHABSIM and provided data for PHABSIM evaluation. Analysis of the 30-year WUA (Weighed Usable Area) estimates supported the development of metrics for fish community analysis, and the analysis of selected fish species populations in each reach. Metrics developed for four of the six species modeled were positively related to the relative differences in numbers of fish present between the two reaches.
Year: 2009