Surface and groundwater dynamic interaction in the Upper Great Chaophraya Plain of Thailand is explored. The surface-soil water model SWAT and the groundwater model MODFLOW are semi-coupled to determine the various hydrological components and their relevant flow behaviour. The coupled models are executed by running the simulations individually using the monthly river-groundwater interactions an...

The dependency of surfaceor groundwater flows and aquifer hydraulic properties on dewateringinduced layer deformation is not available in the USGS's groundwater model MODFLOW. A new integrated hydrologic model, MODFLOW-OWHM, formulates this dependency by coupling mesh deformation with aquifer transmissivity and storage and by linking land subsidence/uplift with deformationdependent flows that a...

Investigation of the interaction of surface water (SW) and groundwater (GW) is critical in order to determine the effects of best management practices (BMPs) on the entire system of water resources. The objective of this research was to develop a modeling system for considering SW–GW interactions and to demonstrate the applicability of the developed system. A linked modeling approach was select...

This paper presents an approach for coupling MODFLOW and MT3DMS for the simulation of variable-density ground water flow. MODFLOW routines were modified to solve a variable-density form of the ground water flow equation in which the density terms are calculated using an equation of state and the simulated MT3DMS solute concentrations. Changes to the MODFLOW and MT3DMS input files were kept to a...

In order to simulate large-scale ground water flow problems more efficiently with MODFLOW, the OpenMP programming paradigm was used to parallelize the preconditioned conjugate-gradient (PCG) solver with in this study. Incremental parallelization, the significant advantage supported by OpenMP on a shared-memory computer, made the solver transit to a parallel program smoothly one block of code at...

Low permeability zones (LPZs) are major sources of groundwater contamination after active remediation to remove pollutants in adjacent high (HPZs). Slow back diffusion from LPZs HPZs can extend management polluted sites by decades. Numerical models often used simulate diffusion, estimate cleanup times, and develop site strategies. Sharp concentration gradients present at the interface between L...

This study proposes a transient groundwater modeling using spreadsheet simulation (TGMSS) model for solving groundwater problems. TGMSS may be considered as a practical method and introduction to groundwater modeling that uses spreadsheets instead of conventional groundwater model codes. Irregular aquifer geometry, variable boundary conditions and sinks and/or source values, heterogeneous aquif...

Historical drainage improvements have created complex hydrological regimes in many low-lying, wet coastal grassland areas. The manipulation of ditch water levels is a common management technique to maintain important in-stream and in-field habitats in such areas. However, in wet grasslands with low soil conductivities the water table in the centre of each field is not closely coupled to variati...