Changing pattern of ground water levels and ground gas concentrations over 13 rounds of (spot) monitoring before, during and after leakage of discharge water from a Combined Heat and Power Plant (NOTE: hypothetical site & conditions). See QGIS3 course for full-screen hi-res video.
LQM have for many years had to make sense of myriad datasets, in multiple data formats and from varied site investigations … ranging from single house plots to large industrial sites or residential estates … previous investigations and risk assessments undertaken by small independents through to large multi-national companies.
One of the most consistently frustrating features of such work is a little more effort at combining the data collected with the right data analysis tools and data formats would have made the original decision-making more effective, cost efficient and ultimately sustainable. Robust data management, analysis and visualisation breeds the sound science and defensible decisions from site investigations regulators demand, stakeholders expect and clients deserve.
Roger Chandler of Keynetix in the Nov/Dec 2018 issue of the AGS Magazine clearly states the importance of using the AGS data format and you cannot argue against the logical efficiency of his two ‘Golden rules’ … only enter data once … and get someone else to do it!
Once you have all of this data in the right format you need a way to interrogate, visualise and evaluate it. For contamination investigations the LQM starting tool of choice is a Geographic Information System (GIS), as each sample you take or monitoring point has a location in space (Easting, Northing, Elevation) and time. Your conceptual site model has the same dimensions and so there is a logical efficiency in using a GIS to store and present your data.
BS ISO 18400‑104:2018 ‘Sampling Strategies’ (and other members of the BS ISO 18400 series) is guidance intended to be used in conjunction with and take precedence over BS 10175:2011+A2:2017 ‘Investigation of potentially contaminated sites’. Part 104 provides guidance on the development of site investigation and sampling strategies taking into account the need to obtain representative samples and to have regard to relevant statistical principles. (We will leave the limitations of non-spatial statistics for another occasion – but Paul Nathanail did cover this in a webinar on geostatistics a year or so ago).
GIS helps us ensure we meet the current standards for data collection, visualisation, data analysis and dissemination of information.
The good news is that free and open source GIS tools such as QGIS are now widely available and have, for most contaminated land situations, comparable functionality to commercial software systems. Indeed QGIS can be integrated with data analytics (e.g. RQGIS). A host of user-friendly plugins also brings more conventional statistical and graphical spreadsheet analysis, such as summary statistics, X-Y scatter plots, histograms, box-plots and even ternary plots directly into the GIS environment (WARNING – non spatial statistics can give misleading results!).
You can quickly load your geotagged site walkover photos into your GIS model and view them conveniently within QGIS as an aid to communication and visualisation to clients and colleagues (see this LQM GIS web-byte). Similarly you can view your borehole logs as images or tables in tandem with your contaminant and other site investigation datasets, helping you more clearly define your conceptual site model, risk evaluation and communication (there’s a LQM GIS web-byte to help you with that too).
If your looking to display your monitoring data as an animated video then QGIS can do that for you too. The major limitation of QGIS for site investigations is knowing what it can do for you and how to do it.
If you would like to learn more; here’s some good news: LQM are running three one-day entirely hands-on courses to cater for both beginners (QGIS 1), current users looking to more efficiently translate data into information and solve problems (QGIS 2) and for those wishing to learn how to create efficient workflows which can be shared with colleagues, save you time and produce reproducible outputs (QGIS3). These courses will help you to inform your conceptual site model, site investigation design, interrogate your SI data and produce informative spatial and temporal infographics and not just meaningless pages of data.
QGIS 1: Building a QGIS project – the road to data visualisation (03 December 2019)
QGIS 2: Solving & Visualising Contaminated Land Problems using QGIS (04 December 2019)
Given the requirements of the British Standards Institute and the important role that the AGS data format plays in achieving a more efficient approach towards site investigation and development, there is little excuse for not investing a little bit of effort to learn how to gain maximum value from some of the great free and open source GIS tools available to us.