Objective
Long term groundwater level monitoring is conducted for a variety of purposes, including characterising existing hydrogeological regimes, identifying temporal changes in hydrogeological regimes, and monitoring groundwater remediation projects. Networks of hydrostatic pressure loggers are often utilised to gain long-term, high resolution groundwater elevation data in groundwater monitoring projects. The large amount of data generated by these long-running data logger networks is time consuming to process and display manually in hydrographs. A custom R code, or script, has been created to streamline this process and automate the production of hydrographs for several large-scale groundwater investigation projects.
Design and Methodology
The script was developed to import raw hydrostatic pressure files and convert them to groundwater elevation, as the well location of each data logger file is identified within the code and matched to manually recorded standing water levels. Additional information can also be displayed to aid in the visual interpretation of the data. Folders of rainfall, tidal, and irrigation information can be imported and matched to the relevant groundwater elevation time series. The script then produces formatted figures displaying these data.
Results
The script has significantly reduced time spent on hydrograph production. The implementation of a defined, repeatable process for data transformation has decreased the potential for human error, and the resulting visualisation of the data has allowed groundwater trends within the monitoring periods of these projects to be observed, including the tidal and rainfall dependent nature of recharge.
Conclusion
The creation of this data processing script made the visualisation of groundwater elevation and environmental data more efficient in several groundwater investigation projects, allowing more time for interpretation. As the collection of high resolution environmental data becomes more common, the lessons learnt from the development of this code can be applied to a wide range of projects.