Maybe confined or unconfined aquifer are terms that would sound familiar from your first hydrogeology class, however it´s a simple definition about the location of the hydraulic head over the vertical limits of your aquifer. It might be that you have employed those terms in different reports, or maybe you have seen this aquifer classification on some environmental impact assessments or geological reports, but which is the relevance of this classification on the groundwater flow? This article talks about the comparison of the the confined / unconfined aquifer condition based on numerical modeling with some discussion about the convertible character of the aquifer.

GRIDGEN is a program developed by the United States Geological Survey (USGS) to create unstructured grids to be used in numerical models such as MODFLOW-USG.

The use of unstructured grids has advantages, like the capacity of refining specific areas. However, its design and manipulation is more complicated than in structured grids. The most complex step is the creation of input data, specifically the ones related to cell connectivity. For this reason, GRIDGEN is an useful tool that helps to simplify the process.

The United States Geological Survey (USGS) has just released the latest MODFLOW version: MODFLOW 6. It is the sixth core version of MODFLOW to be released by the USGS (previous core versions were released in 1984, 1988, 1996, 2000, and 2005).

Constructing and calibrating numerical models can be a challenging task in terms of time, available data and professional abilities of the modeler. Since this work is usually done alone, there are many questions about the conceptualization of the physical environment, the construction of the model and the calibration with observed data. Based on the questions asked by some attendees of our webminars, we have written this article for all the confused hydrogeological modelers.

Evapotranspiration is the mixed process of soil evaporation and transpiration of plants. This process is not included in many Hydrology books or in hydrological methods like the rational method, SCS, among others. Evapotranspiration is not relevant in when calculating maximum floods, but it is considered in water balances of superficial water and groundwater.

This article shows the relevance of the evapotranspiration process in the conceptualization and modeling of groundwater, indicating which would be the errors and inaccuracies of not considering this process.

A hydrogeological evaluation needs a numerical representation of the groundwater flow regime. Numerical models are a great tool to evaluate the current and future conditions of groundwater flow. In order to make a model, it is necessary to have geological and climate data, among other types.

The following list describes the input data needed to carry out a hydrogeological modeling. The information required could be either in tabular or vectorial format.

Impact on groundwater flow from mining facilities could be evaluated many times along the different mining phases, many of these evaluations are done by different consultant companies. This post is focused on strategies and best practices for cost (& time) optimization, specially for hydrogeological investigation on mining projects. 

In the actual society, the environmental aspects are a concern when planning projects related to water resources. In this context, numerical models are useful tools to represent the superficial water and groundwater cycle and determine the contamination effects.