Groundwater Flow Modeling Using Mesh Free Analytic Element Method: A Case Study of Astaneh-Kouchesfahan Plain, Gilan Province, Iran

Astaneh-Kouchesfahan Plain is an important water resource system in the northern Iran. In this study, Astaneh-Kouchesfahan plain’s groundwater flow was modeled in the steady state using mesh free analyticelement method (AEM). AEM performs the modeling using exact analytic functions but it does not need mesh-dependent interpolation functions. In this method, each exact analytic function expresses a hydrological and geological feature, which affects aquifer systems. In order to model Astaneh- Kouchesfahan plain’s aquifer in AEM, the uniform flow, line sink, point sink and area sink elements were used. PSO algorithm was utilized to calibrate the model. Analytic element model and the PSO algorithm were developed and implemented in Python OOP language. During the calibration process, using collected data in March 2010, hydraulic conductivity was calculated to be 12.75 m/day and SefidRud’s river bed conductance range 320 to 1200 m2/day. Correlation coefficient for both hydraulic conductivity and the river bed conductance was calculated to be 0.8709. Flow modeling was performed using the aforementioned parameters and the results were compared with data collected in June 2010. Modeling results indicated a correlation coefficient of 0.8877.