The nonhorizontal-model-layer (NHML) grid system is more accurate than the horizontal-model-layer grid system to describe groundwater flow in an unconfined sloping aquifer on the basis of MODFLOW-2000. However, the finite-difference scheme of NHML was based on the Dupuit-Forchheimer assumption that the streamlines were horizontal, which was acceptable for slope less than 0.10. In this study, we...

FloPy is a Python package for developing, running, and post-processing models that are part of the MODFLOW family of codes. FloPy includes support for MODFLOW-2000, MODFLOW-2005, MODFLOW-NWT, and MODFLOW-USG. Other supported MODFLOW-based models include MODPATH (version 6), MT3DMS and SEAWAT. If you think you have found a bug in FloPy, or if you would like to suggest an improvement or enhanceme...

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...

The accuracy with which MODFLOW simulates surface water-groundwater interaction is examined for connected and disconnected losing streams. We compare the effect of different vertical and horizontal discretization within MODFLOW and also compare MODFLOW simulations with those produced by HydroGeoSphere. HydroGeoSphere is able to simulate both saturated and unsaturated flow, as well as surface wa...

As a widely used groundwater flow model, MODFLOW offers a set of packages to simulate hydrologic stresses, inflows and outflows, to a groundwater system. Specifically, MODFLOW lacks a general method to process areally distributed recharge and discharge to groundwater. One solution would be to create a new package for MODFLOW. Alternatively, it is also possible to make the best use of existing c...

A key aspect of estimating transmissivity distributions from pumping tests is the spatial resolution of the estimation. Some assumption of spatial structure is needed to make an inversion possible. Both the nature of groundwater flow and assumed structure cause a smeared estimate. This research is focused on the how information content of the data smears the estimate. The inversion procedure ne...

Exercise 3.2d: Calculate weights on hydraulic-head and flow observations For the head observations, first calculate the total variance of measurement error for the head observations, by adding the variance for the elevation measurement and the variance for the water-level measurement. This total variance is 1.0025 m, as shown in Table 3.2. Then, calculate the weight as the inverse of this varia...

Prior to using MODFLOW, students need experience with simpler codes that provide “hands-on” experience setting up boundary and initial conditions, coding simple solution algorithms, and handling numerical errors. The best way to do this is using spreadsheet models; faculty no longer can expect students to know a common computer language, but students are familiar with spreadsheets. Many aspects...

The City ofRostov the Great (Rostov) is one of the oldest cities in the Russian Federation. Many buildings need to be restored due to advanced degradation of the wooden and stone foundations. This degradation and other environmental problems are in large part caused by high groundwater levels, which are in turn directly associated with human activity over the years. Technical analyses were comp...