The Patagh dam is under construction in the Kermanshah province, west of Iran. The right abutment of the dam is located on Ilam-Sarvak limestone which has the potential of karstication. This limestone is discharged by several springs including Gelodareh spring. In order to study the possible leakage through the dam, a dye tracing test was organized in PC208 borehole near the dam. The recession coefficients and hydrochemical data of the Gelodareh spring show that the flow regime of the area is of diffuse type. The dye was appeared in the water samples of PC206 borehole and Gelodareh Spring, which are located downstream of the dam. This imply the hydraulic connection between injection well and these points. Therefore, the potential of seepage through the right abutment of the dam is exist. The measured mean flow velocity to PC206 borehole (0.86 m/h) denotes to diffuse flow regime. The breakthrough curve of the Gelodareh spring shows multiple peaks without significant tail except the last one. Besides, the high flow velocity (11.8 m/s) contradict the diffuse flow regime. The ambiguous behavior of the dye breakthrough curve of the Gelodareh spring is explained by a combination of siphon and diffuse flow systems. Existence of a siphon flow system explains the multiple periodic peaks of breakthrough curve without tail. The last peak with tail is result of diffuse flow system. A neck, close to the spring or the main conduit which conveys water to the spring, might be causing the pseudo-steady state behavior of spring discharge and vanishes the periodic discharge fluctuation which is created by siphon. It is probable that the siphon level situated in the zone of water level fluctuation.
کلید واژگان :Dye tracing, Karst, Breakthrough curve, Patagh dam, siphon
ارزش ریالی : 600000 ریال
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