Abolfazl Shamsai - Professor of Civil Engineering Department, Sharif University of Technology
Reza Ghasemizadeh - Graduate Student of Environmental Engineering, Sharif University of Technology
Arash Niroomandi - Graduate Student of Water Engineering, Sharif University of Technology
Moretza Mohamadi - Graduate Student of Geotechnics Engineering, Sharif University ofTechnology

This paper describes the application of statistical data in estimation of future trends and periodicity in stream flows of Zayandehrood River. Assuming the steady state conditions, the correlation between flow and concentration of chosen soluble chemicals such as calcium, magnesium, carbonates, sulphates, anions, cations and EC is developed. A logarithmic model is derived and in a concentration versus flow plot, a hysteresis effect is observed. In spite of the simplifying assumptions involved in development of the equations, the various relationships between flow and concentration of solutes are suitable. The amount of raise in concentration of some chemicals, by passing through Isfahan is recognizable in Q-C-X diagrams.

Zayandehrood River, Soluble chemicals, Water quality prediction,Stream flow variability, Hysteresis