Abstract for: Simulation of Drainage Systems in unsteady state condition, using system dynamics

The system dynamics technique is one of the object oriented approach that studies and manages complex feedback systems. Its merits include the friendly and easily development and improvement of model. Itís also used as a decision tool for engineering problems.In this paper, the system dynamics technique was used to simulate the performance of a drainage system in unsteady state condition. The model is capable to predict many hydrological parameters such as water table fluctuation, drainage discharge, upward flux, evapotranspiration, deep percolation, infiltration, runoff, soil moister content and unsaturated hydraulic conductivity on the basis of variation of soil moister content. All above parameters were investigated theoretically and their trends were found to be legible. The model was validated using observed experimental field data collected from amirkabir unit in sugar beet development plan located at khozestan, Iran. The observed data were water table level and drainage discharge. The standard error index was calculated to determine the agreement between the observed and simulated values of water table and drainage discharge. The results indicated that S.E. for water table and drainage discharge were 10.2 and 0.13 centimeter per day respectively.