Making an Environmental Impact Assessment using ONLY Open Source Software

The study of the environment, the understanding of the water cycle / atmospheric processes and the interaction with the aquatic and terrestrial ecosystems needs advanced analysis tools.

It is important to understand how the environment works and the potential impacts of our actions in the future. This goes further than a regulatory approach, we need a constant search and evolution of codes and models and this is where open source software has important advantages.

To have a glimpse about what we mean when we mention about ‘Open Source’, kindly read our article on “What is Open Source?.”

We are going to provide links to and explain the different software tools that can be used in order to conduct your assessment.

For Text and Data processing

To process text documents you can use LibreOffice ( which is the free version of Microsoft Office. The packages are similar to the ones we already know about:

  • Microsoft Word is LibreOffice Writer
  • Microsoft Excel is LibreOffice Calc
  • Microsoft Power Point is LibreOffice Impress

For the analysis of long time series data we recommend Python ( through the Anaconda suite ( Also R (, which is a good option that processes continuous data and spatial files.

For spatial data analysis and generation of maps

Our main recommendation is QGIS ( This software has grown a lot in the past few years and the version 3 is the most current one. QGIS lets you process, analyze and represent vectorial datasets and rasters.

In QGIS you can represent populations, ecosystems, water bodies, define influence and affected zones.

For air quality modeling

To model the discharge of emissions from chimneys the best option is Aermod, which is developed by the EPA ( It is easy to use since it performs a 2D calculus.

For more complex configurations and 3D modeling we recommend OpenFoam (

For Hydrological modeling

To represent precipitation, runoff and storm events on a daily scale, we recommend HEC-HMS ( This software has a great GUI and is easy to use. The software lets you implement several hydrological rainfall, loss, runoff and routing models.

SWAT ( is also an interesting software since it lets you perform hydrological and water quality modeling. It can also be used as a QGIS complement.

To model the mixing zone related to discharge points, OpenFOAM is recommended ( This software is for fluid modeling, may be water or air, and can model laminar or turbulent, miscible or immiscible, compressible or incompressible conditions

To model groundwater flow

Our number one option is MODFLOW, which is a code to model saturated and unsaturated groundwater flow in 3D in regional and local scale. MODFLOW can represent different elements that affect groundwater flow such as wells, recharge, evapo-transpiration, among others.

Contaminant transport can be coupled to the MODFLOW flow model using the code MT3DMS.

We hope that this list can show you a new perspective of the current status of open source software to evaluate the environment and potential impacts.

About the Author


Kumbirai is a 4th year Surveying & Geomatics students at the Midlands State University in Zimbabwe. He is also the Founder and Team Lead at African Surveyors Connect. He enjoys spending time writing web-applications and is more of a GIS enthusiast who mainly focuses and grew interests in Health and Land Administrative Applications of Geographic Systems.

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