MODFLOW is a groundwater modeling program. It can be compiled and remedied according to the practical applications. Because of its structure and fixed data format, MODFLOW can be integrated with Geographic Information Systems (GIS) technology for water resource management. The North China Plain (NCP), which is the politic, economic and cultural center of China, is facing with water resources sh...

In an age of both big data and increasing strain on water resources, sound management decisions often rely numerical models. Numerical models provide a physics-based framework for assimilating making sense information that by itself only provides limited description the hydrologic system. Often, are best option quantifying even intuitively obvious connections between human activities resource i...

First posted March 3, 2022 For additional information, contact: Director, Integrated Modeling and Prediction DivisionWater Mission AreaU.S. Geological Survey12201 Sunrise Valley Dr., MS 411Reston, VA 20192-0002Contact Pubs Warehouse This report documents a new Groundwater Transport (GWT) Model for MODFLOW 6. The GWT simulates three-dimensional transport of single chemical species in fowing grou...

The MODFLOW Lake Package is integrated into the FREEWAT GIS environment in order to simulate surface water groundwater interaction using state of the art techniques for numerical simulations, thus allowing the improved consideration of surface water bodies for water resources management. Surface water bodies, both stationary and flowing, can strongly affect groundwater elevations and flow patte...

The effect of future climate scenarios on surface and groundwater resources was simulated using a modeling approach for an artificial recharge area in arid southern Iran. Future climate data for the periods of 2010–2030 and 2030–2050 were acquired from the Canadian Global Coupled Model (CGCM 3.1) for scenarios A1B, A2, and B1. These scenarios were adapted to the studied region using the delta-c...

A three-dimensional model for predicting redox controlled, multi-species reactive transport processes in groundwater systems is presented. The model equations were fully integrated within a MODFLOW-family reactive transport code, RT3D. The model can simulate organic compound biodegradation coupled to different terminal electron acceptor processes. A computational approach, which uses the spatia...

This paper presents the program KALMOD which has been developed to enable the execution of the integration of the Kalman filtering and the numerical groundwater flow model MODFLOW on microcomputers. The program can be applied to quantify and reduce the uncertainty of the groundwater flow model, and to analyse and design groundwater monitoring networks. KALMOD consists of a preprocessor, a proce...

The contaminant transport equation is solved in three dimensions using the Eulerian–Lagrangian Localized Adjoint Method (ELLAM). Trilinear and finite volume test functions defined by the characteristics of the governing equation are employed and compared. Integrations are simplified by forward tracking of integration points along the characteristics. The resulting equations are solved using a p...

PHT3D, a three-dimensional, MODFLOW/MT3DMS-based reactive multicomponent transport model is presented. The model couples, via an operator-splitting method, the transport simulator MT3DMS (Zheng and Wang, 1998) and the geochemical package PHREEQC-2 (Parkhurst and Appelo, 1999). Through the flexible, generic nature of PHREEQC-2, PHT3D can handle a broad range of equilibrium and kinetic reactive p...