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GWSDAT

GWSDAT Version 3.1 now released!

Updates Include:

  • Well Redundancy Analysis: This allows the user to very conveniently drop a well or a combination of wells from the analysis and investigate the resultant impact.
  • Updated User Manual: http://gwsdat.net/gwsdat_manual. A fully comprehensive description of GWSDAT, updated for version 3.1.
  • Excel Add-in Menu: New Excel menu designed to be clearer to navigate and easier to install.
  • Custom Colour Key: In response to user feedback, the latest version has the functionality to customise the colour key in the main GWSDAT spatial plot.
  • Updated branding: The Excel data input templates have been updated with more contemporary colour schemes.
  • Bug Fixes: Numerous bug fixes and enhancements. More robust data input procedures which report more thoroughly on any potential issues, e.g. missing data, incorrect units, etc.

GroundWater Spatiotemporal Data Analysis Tool (GWSDAT)

GWSDAT is an open source, user-friendly, software application for the visualisation and interpretation of groundwater monitoring data. It also enables to work with other types of monitoring data collected over time and space (e.g. soil gas concentrations).

Key functionalities of tool:

  • Trend analyses
  • Data smoothing
  • Spatiotemporal smoothing
  • Determination of contamination plume characteristics
  • Well redundancy analysis
  • Automatic report generation tools based on user input.

Business Benefits

GWSDAT, through improved risk-based decision making and response, adds value in several different ways:
  • Early identification of increasing trends or off-site migration.
  • Evaluation of groundwater monitoring trends over time and space (i.e., holistic plume evaluation).
  • Nonparametric statistical and uncertainty analyses to assess highly variable groundwater data.
  • Reduction in the number of sites in long-term monitoring or active remediation through simple, visual demonstrations of groundwater data and trends.
  • More efficient evaluation and reporting of groundwater monitoring trends via simple, standardised plots and tables created at the ‘click of a mouse.’
  • Well Redundancy Analysis functionality to identify potential optimization measures with regards to monitoring well network sampling locations.

 

Background

Introduction

The GroundWater Spatiotemporal Data Analysis Tool (GWSDAT) has been developed by Shell Global Solutions for the analysis of groundwater monitoring data. It is designed to work with simple time-series data for solute concentration and ground water elevation, but can also plot non-aqueous phase liquid (NAPL) thickness if required. Spatial data is input in the form of well coordinates, and wells can be grouped to separate data from different aquifer units. The software also allows the import of a site basemap in GIS shapefile format. Concentration trend and 2D contour plots generated using GWSDAT can be exported directly to Microsoft PowerPoint and Word to expedite reporting.

Software Architecture

The application is supported for Windows 8 & 10 and the corresponding version of Microsoft Office (including 64-bit operating systems). Data input to GWSDAT is via a standardized Excel spreadsheet and the data analysis and plot functions are accessed through an Excel Add-in application. The statistical engine used to perform geo-statistical modelling and display graphical output is the open- source statistical programming language R (www.r-project.org). A user manual and two example datasets are provided with the software for training and demonstration purposes.

GroundWater Spatiotemporal Data Analysis Tool (GWSDAT)  Excel


Spatiotemporal Data Analysis

The modelling of solute distribution in groundwater is typically restricted to either the analysis of trends in individual wells or independent fitting of spatial concentration distributions (e.g. by Kriging) to data from monitoring events. Neither of these techniques satisfactorily elucidate the interaction between spatial and temporal components of the data. GWSDAT applies a spatiotemporal model smoother for a more coherent and smooth interpretation of the interaction in spatial and time-series components of groundwater solute concentrations. A spatiotemporal concentration smoother is fitted for each analyte using a non-parametric regression technique known as Penalised Splines (Eilers and Marx, 1992, 1996). A Bayesian methodology is used to select the appropriate degree of model smoothness (Evers et al, 2015) The fit of the spatiotemporal algorithm to the monitoring data can be evaluated.

Screenshot of GWSDAT tool spatiotemporal model


Graphical User Interface

The GWSDAT graphical user interface (GUI) allows the user to navigate through a groundwater dataset and explore concentration/ groundwater elevation trends in individual wells and across the site. Several options are available to customize the display and data analysis. Note that plots can also be automatically exported.

GWSDAT graphical user interface 1

GWSDAT graphical user interface 2

 

Data Visualisation

GWSDAT includes the following tools for trend visualization and detection:

Spatial plot: For the analysis of spatial trends in solute concentrations, groundwater flow and, if present, NAPL thickness. Overlaid on this plot are the predictions of the spatiotemporal solute concentration smoother which is a function that simultaneously estimates both the spatial and time series trend in site solute concentrations. GIS shapefiles can also be overlaid on this plot.

Screenshot of GWSDAT tool spatial trend visualization


Well Trend plot:
For the investigation of historical time-series trends in solute concentrations, groundwater elevation and, if present, NAPL thickness for individual wells. Users can overlay a nonparametric smoother which estimates the time-series trend in solute concentration. The advantage of this nonparametric method is that the trend estimate is not constrained to be monotonic, i.e. the trend can change direction.

Well Trend plot 


Trend and Threshold Indicator Matrix:
This feature provides a summary of the level and time series trend in solute concentrations at a particular model output interval.

Screenshot of GWSDAT tool trend and threshold indicator matrix


Plume diagnostic:
This feature enables to calculate and display plume diagnostic quantities (area, mass, concentration) for a delineated plume displayed with a solid red contour line.

Plume diagnostics plots 2

Plume diagnostics plots 1 


Well Redundancy:
This features enables to very conveniently drop a well or a combination of wells from the analysis and investigate the resultant impact.

Well redundancy 1

Well redundancy 2


Useful Links & Presentations


Acknowledgements

The authors gratefully acknowledge those people who have contributed their knowledge and time to the development of GWSDAT. The authors wish to express their gratitude to Adrian Bowman, Ludger Evers and Daniel Molinari from the department of Statistics, University of Glasgow, for their invaluable contributions to the development of the spatiotemporal algorithm. Thanks also to Ewan Mercer from the University of Glasgow for his assistance in the development of the GWSDAT user interface. We acknowledge and thank the R project for Statistical Computing and all its contributors without which this project would not have been possible. A big thank you to Shell's worldwide environmental consultants for assistance in evaluating and testing the earlier versions of GWSDAT. Thanks also to the Shell Year in Industry students who spent a great deal of time testing GWSDAT and making suggestions for improvements. We thank both current and former colleagues including Matthew Lahvis, Jonathan Smith, George Devaull, Dan Walsh, Curtis Stanley, Marco Giannitrapani and Philip Jonathan for their support, vision and advocacy of GWSDAT.


References


Installation Instructions

System Requirements: Windows 8 or 10. Microsoft Office versions: 365, 2016, 2013, 2010. You need to be connected to the internet when you install GWSDAT version 3.1.

  • Download and install the latest version of the open source statistical application "R" available from: http://cran.r-project.org/bin/windows/base/. Please accept all default settings during installation. (Users must have administrator access rights to install R).
  • Download the GWSDAT_v3.10 zip file from below and unzip to somewhere on your C: Drive which is read/writable, e.g. C:\Users\A.N.Other\GWSDAT.  
  • Open Excel and install the GWSDAT add-in by choosing: "File" > "Options""Add-Ins" > "Go" > "Browse" and then select "GWSDAT V3.10.xlam" located in the "C:\Users\A.N.Other\GWSDAT\GWSDAT_v3.10" folder. To avoid any Excel add-in security issues please ensure that this is a trusted location. See link here for troubleshooting Excel Add-in installation issues.
  • A menu called "GWSDAT v3.10" will appear in the EXCEL ribbon (on right side) along the top of the EXCEL window.

For older version

System Requirements: Windows XP, Vista, 7, 8, 10. Microsoft Office versions: 2007, 2010, 2013, 2016.

  • Download and install the open source statistical application "R”. Note that version 3.00 of GWSDAT only works with R version<4.0.0. Hence, please download and install version 3.6.3 of R available here: https://cran.r-project.org/bin/windows/base/old/3.6.3/. Please accept all default settings during installation. (Users must have administrator access rights to install R)
  • Download the GWSDAT V3.00 zip file from below and unzip to somewhere on your C: Drive, e.g. "C:\Users\A.N.Other\GWSDAT_v3.00". To avoid any Excel add-in security issues please ensure that this is a trusted location – see here for more details.
  • Open up Excel and install the GWSDAT add-in by choosing: "Office button" > "Excel Options" > "Add-Ins" > "Go" > "Browse" and then select "GWSDAT V3.00.xlam" located in the "C:\Users\A.N.Other\GWSDAT_v3.00" folder.
  • Repeat the above step and select "GWSDAT V2.13.xlam" to install the original version.

Getting started

  • To get started with a basic example activate menu by clicking on “GWSDAT v3.10”and then select “Open Example” -> select “Basic Example" and then select "Analyse”.
  • Note- the first time you run this it may take a while as it needs to download and install some additional R packages.
  • To get started with a more complex example activate menu by clicking on “GWSDAT v3.10”and then select “Open Example” -> select “Comprehensive Example”, and then select "Analyse”.


Downloads


Help and Support

Please see http://gwsdat.net/gwsdat_manual/ for comprehensive user manual and supporting material. To report any software issues or bugs please fill in the user feedback form here: www.gwsdat.net/feedback.

Please note that the API / Shell Global Solutions do not provide consultancy on data interpretation or use of the GWSDAT software.

Further details on GWSDAT at www.gwsdat.net