Estimation and analysis of the water age in Dez reservoir, using CE-QUAL-W2

Considering the fact that the water circulations in fluid environments are greatly complicated, it is so hard to achieve a deep understanding about them by using simple methods. Therefore, it is essential to use special techniques to investigate and explain them. Most of these methods required to use some auxiliary variables. The concept of water age is one the most important ones. The concept of water age can be defined as the time taking a water parcel to leave the domain which its age prescribed to be zero. In this research the water age of the Dez reservoir were estimated by using a two dimensional laterally averaged model, CE-QUAL-W2, and the dominant hydrodynamic processes to the age of inflow water in Dez reservoir were illustrated. The Dez reservoir was separated into two halves, from the volumetric aspects, and the results showed that the water age in the second section was shorter than that in the first one; as a result, the sedimentation, the main problematic issue in Dez reservoir, would be more probable in the second section. Moreover, it was shown that the mean residence time of river water in the reservoir, which is hard to be estimated, can be estimated more easily by using the water age concept. This simulation was executed for a period of two years (2002-2003). The comparison of the measured temperature profiles and surface water elevations with observed values indicated that there was a good accuracy in both calibration and verification stages.

کلیدواژه ها:

Water age ، Dez reservoir ، CE-QUAL-W2 ، hydrodynamic processes ، mean residence time