Simulation optimization model for aquifer parameter estimation using coupled meshfree point collocation method and cat swarm optimization

Abstract

Here we propose a new simulation-optimization model (S-O) for aquifer parameter estimation by coupling radial point collocation meshfree method (RPCM) with cat swarm optimization (CSO). The decision and state variables are zonewise transmissivity values and hydraulic heads at the predefined locations, respectively. The hydraulic head values obtained using RPCM acts as input for the CSO model. The RPCM-CSO model minimize sum of the weighted squared difference of simulated and observed hydraulic heads for different realization of transmissivity values. Further for comparison, RPCM model is coupled with particle swarm optimization (PSO) and elitist-mutated PSO (EMPSO). The RPCM-CSO model has been applied to estimate the zonal transmissivity values of a synthetic aquifer for validation and to a field problem. For synthetic problem, the transmissivity values are compared with available results. The RPCM-CSO model is more accurate than other models based on the genetic algorithm (GA) and PSO. For the field problem, average percentage error in parameter estimation using RPCM-CSO model is 1.555%, for RPCM-PSO is 3.145% and for RPCM-EMPSO is 2.270%. Further a reliability analysis carried out showed that RPCM-CSO model is accurate and efficient to estimate the transmissivity values. This study showed the effectiveness of RPCM-CSO model for aquifer parameter estimation.