Evaluating sedimentation effect on reservoirs water quality: a case study, Shahriyar reservoir

Abstract

In this research, total dissolved solids (TDS) was simulated by CE-QUAL-W2 software in two scenarios of with and without sedimentation in normal, dry, and wet periods of inflow for Shahriyar reservoir, an under-construction dam located in Iran. Shahriyar reservoir is a dam with a total capacity of 700 million cubic meters (MCM) and a dead volume of 360 MCM. In case of with sedimentation compared with without sedimentation, results showed an annual average increase of 4, 4.3, and 8.7% in TDS of outflow for normal, wet, and dry periods, respectively. There is no significant change in TDS profile of the reservoir in both conditions. According to the average outflow TDS of 1448, 1301, and 1555 mg/L compared with the average inflow TDS of 1714, 1520, and 1835 in normal, wet, and dry conditions, respectively, the effect of dam on inflow TDS adjustment can be also observed. With the mentioned outflow TDS, there is no limitation to use of reservoir water for agricultural purposes based on FAO irrigation guidelines for both scenarios.