TY - JOUR ID - 88245 TI - Effect of different hydraulic conditions on the hyporheic flow charachteristics around gabion weir structures JO - Iranian journal of Ecohydrology JA - IJE LA - en SN - 2423-6098 AU - pourhosein ghadi, mehrdad AU - dehghani, amir ahmad AU - Meftah Halghi, mehdi AD - PhD Student, Department of Water Engineering, University of Agricultural Sciences and Natural Resources, Gorgan, IRAN AD - Associated Professor, Department of Water Engineering, Gorgan University of Agricultural Sciences and Natural Resources AD - Associate Professor, Department of Water Engineering , University of Agricultural Sciences and Natural Resources, Gorgan Y1 - 2022 PY - 2022 VL - 9 IS - 1 SP - 15 EP - 33 KW - Hyporheic Zone KW - Hyporheic Flow KW - Gabion Weir KW - Flow pattern KW - Residence Time DO - 10.22059/ije.2022.329091.1539 N2 - Gabion weir at the longitudinal variation of hydraulic head causes that surface flow enters the porous medium and mix with the subsurface flow and return to the surface water flow again. This mixing takes place in the hyporheic zone play an important role in the river ecology. In this study, the flow pattern around the gabion weir structure was investigated by conducting laboratory studies. The particle pathes were traced by injection of dye and the hydraulic head profiles were measured under different hydraulic conditions. Downstram hydraulic conditions were also adjusted in order to create three flow conditions, including through flow gabion weir (TFGW), overflow gabion weir with no hydraulic jump (NFGW) and overflow gabion weir with hydraulic jump (PNGW).In order to investigate the characteristics of the hyporheic zone, the measured hydraulic head on the sediment-water interphase was introduced as a drichlet boundary to the groundwater model and flow modeling was performed in a porous media. The results show that there is a good agreement between the observed and computational flow pattern in the hyporheic zone.The observations showed that in TFGW and NFGW flow conditions, the particle pathlines are downstream directed upwelling (DDU) and in PNGW flow condition, there are both upstream directed upwelling (UDU) and downstream directed upwelling (DDU).Also the hyporheic exchange flow (Qex) was ranged between 1.63 and 2.80 l/s.The residence time in all flow conditions increases with decreasing Reynolds number. In this study, the relationships with high accuracy were presented for estimating residence time and hyporheic exchange flow. UR - https://ije.ut.ac.ir/article_88245.html L1 - https://ije.ut.ac.ir/article_88245_21918efbbdafde6664aeee4bf2de2bd4.pdf ER -