Optimised calibration of regional groundwater model through inverse modeling

Regional groundwater modeling is always constrained by lack of data and lack of understanding of system uncertainty. Inverse modeling of groundwater flow provides both an efficient automated parameter calibration and an additional uncertainty assessment of physically based model. The inverse groundwater modeling was used to identify model parameters and understand uncertainties associated with the regional hydrogeology and groundwater model in Belfast, Northern Ireland. The automated calibration of the model parameters, boundary condition and regional recharge was carried out using non-linear least squared optimisation. The regional groundwater flow model was constrained by uncertainty analysis during the optimal calibration. The sensitivity and confidence intervals obtained from the inverse modeling indicate that the major uncertainties were insufficient head observations and effect of the complex topography in the region. The approach is proved valuable for better understanding of the regional hydrogeology.