Current approaches to modeling geofiltration in urban areas

Abstract

Background. The purpose of the study is to develop theoretical concepts and applied approaches to modeling hydrogeological processes in space and time under the influence of natural and anthropogenic factors.

Methods. Hydrogeological modeling is one of the most effective and reliable tools for studying and predicting underground flow processes. Among numerical methods, the finite difference method, implemented in the well-known Processing MODFLOW software package, is most often used. Accurate determination of hydrodynamic pressures at the epignosis modeling stage is key to improving the accuracy of predictive calculations. To refine the geofiltration parameters of aquifers and the intensity of infiltration recharge, it is necessary to adjust the surface of the hydrodynamic head. Accuracy of parameters can be achieved when the model head values agree with actual measurements within the acceptable error range. To improve the reliability of the spatial position of the hydrodynamic head surface, it is proposed to use a tool independent of hydrogeological modeling – the Darcy Flow module in ArcGIS – to reproduce the head surface before the calibration stage.

Results. The proposed approach was tested on the example of a residential area in Kyiv. The direction and general trend of the underground flow, determined at the first stage in ArcGIS using the Darcy Flow module, were used to calibrate the geofiltration parameters of the model and the intensity of infiltration recharge by comparing the calculated groundwater levels with actual observation data. The high degree of agreement between the field and model results for determining the hydrodynamic head at selected points confirms the reliability and accuracy of the modeling results. The calculations prove the effectiveness of the combined use of the Darcy Flow module (ArcGIS) and the Processing MODFLOW software package for hydrogeological analysis.

Conclusions. Theoretical and applied approaches to modeling hydrogeological processes in urbanized areas have been substantiated and proposed. The results confirm the feasibility of applying the proposed integrated approach to optimize the practical use of the deterministic finite difference method in groundwater modeling based on engineering and geological survey data. The proposed methodology significantly improves the reliability and efficiency of deterministic geofiltration models.