Writers : Mozafari, Morteza; Raeisi, Ezatollah; Zare, Mohammad; Mohammadi, Zargham; Bahadori, Farahtaj
Refference : The 26th Symposium on Geoscieences;Tehran
Publishing Year : 1386

Abstract :
The Doosti dam with a reservoir capacity of 1250 Million cubic meters was constructed on Harrirood river in northerneast Iran, at the border of Turkmenian and Iran. The dam provides water for 50000 hectares of Turkmenian and Iranian agricultural fields, as well as drinking water for Mashad Province. The study area is located in the east of Kopedagh zone. The formations on the right abutment of the dam are composed of Neyzar sandstone, Kalat limstone and Pesteligh alternative layers of marl and sandstone. After filling up the dam reservoir, four springs emerged from the Pesteligh and Neyzar Formations and seepages emerged from the alluvium, 2.8 km downstream of the dam. The maximum discharge ofthese springs is 2, 2, 5 and 70 l/s, respectively. Fifteen kilograms of uranine were injected in a 113 m deep borehole in the Pesteligh Formation. Dye was detected in boreholes and springs that were in direct contact with parts of the Pesteligh Formation having the same sandstone layers as the injection borehole. The dye tracing revealed that the hydraulic connection of permeable sandstone layers was disconnected by 10 to 20 m thick marl layers. The dye velocity was in the range of diffuse flow regime, confirming the efficiency of a grout curtain in the Pesteligh Formation. No dye was detected in Kalat and Neyzar Formations near the dam body because the injection borehole was not in direct contact with these formations. New dye tracing is required to check the efficiency of the grout curtain in these formations.
Subject List : Dam