Use of Geospatial Technology in Assessing Geology

Given the advancement in technology in recent years, it is imperative that geological surveys harness this growth to develop applications to aid geological understanding.

The Groundwater Programme, Geological Survey of Ireland

The Geological Survey of Ireland’s (GSI) Groundwater Programme aims to understand and protect Ireland’s groundwater resources and, therefore, drinking water supplies and surface water quality. To achieve these goals, the Groundwater Programme continues to acquire data for the island of Ireland and advance hydrogeological conceptual understanding, using the most up-to-date technology available.

The Groundwater Programme’s “Groundwater 3D” began in early 2015 as a four-year project. Groundwater 3D (GW3D) aims to produce three-dimensional (3D) subsurface models that will provide sound geological science to meet the requirements of our stakeholders (e.g., local authorities, national government agencies, environmental consultants and the general public). The GSI anticipates these new 3D data products will benefit end-users by facilitating the management of resources, such as wholesome drinking water supplies and the environment.

GW3D will allow us model at sub-regional, catchment or sub-catchment scales:

  • surface and subsurface flow within certain Karst regions of Ireland
  • sand and gravel bodies for water resources and as potential contaminant flow pathways
  • groundwater flow and chemistry within the layers of interest (e.g., the transition zone)
  • natural groundwater chemistry, starting with the national picture for certain parameters.

GW3D involves data collection, data collation, field mapping, data interpretation, report production and technical modelling. The field mapping includes extensive well audits and groundwater level monitoring, karst feature mapping, karst tracer testing, logging subsoil and bedrock exposures, flow gauging, and supervising subsoil and bedrock drilling. Owing to the range of field mapping, associated varied data types and the amount of data collected, effective and efficient data management is a critically important facet of GW3D. This article describes the technology used, from data collection apps to data dissemination apps, and outreach, over the project timeframe. It also touches on our approaches to mapping karst features.

Figure 1. Data collection app – Wells. Image Credit: Shane Carey

Data collection – from app to map

As technology continues to develop, so does the breadth of useful applications (apps) available to GSI. The GSI and Groundwater Programme have positioned themselves to be able to harness growth in the digital technology sector. In-house expertise is being encouraged to develop apps fit for specific data collection and management purposes (Figure 1). As such, the GW3D mapping team has been able to improve its efficiency and accuracy by using a number of in-house data collection apps, avoiding the associated time and potential errors (e.g., georeferencing) necessary to digitally transcribe field information. The advantages of this approach are:

  • Data are backed up in real time and GPS locations are verified.
  • Photographs of the site are geotagged so their exact location has been stored (Figure 2).
  • GPS coordinates of the site are attained through tablet device using robust technology and backed up onsite.
  • Data are captured digitally, minimising data input time for field geologists.

Capturing information with the geological fieldwork app allows for the data to be imported into a desktop Geographic Information System (GIS) mapping package, where it can be further analysed. The latest GIS technology is used for this project, namely ArcGIS 10.1.

Figure 2 shows an example of how photographs are automatically geotagged with the exact data point location. Significantly, these can be further integrated with any relevant data easily and with negligible errors using the GIS mapping package.

Figure 2. Geotagged photograph of karst feature mapped in County Cork. Image Credit: Shane Carey

Field data are now captured using the geological fieldwork app in tandem with the GIS mapping package for all thematic areas of the GW3D project, which, to date, has included:

  • Karst feature mapping in Rathcroghan, County Roscommon
  • Borehole data capture in North County Cork
  • Sand and gravel aquifer mapping in Castletown Geoghegan, County Westmeath.

Remote sensing approaches to karst modelling

Traditionally, karst feature mapping involved laborious and time-consuming mapping in the field with a hand-held GPS, camera and field notebook; however, with the advancement in remote sensing technology and data capture, the GSI is exploring novel approaches to field mapping. Lidar (Light Detection and Ranging) is a remote sensing surveying method used to map the topographic surface of the Earth. The GSI has been investigating its use for karst feature mapping in an Irish geological context (Figure 3).

Figure 3. Karst feature mapping using Lidar data (Co. Roscommon). Image Credit: Shane Carey

Using the latest 3D technological software and high resolution Lidar data, it is now possible to undertake remote mapping assessments from the office. This work is followed by targeted field mapping to validate specific features detected by the Lidar data. The 3D software used to visualize the data is called Virtalis Geovisionary. The software was developed by Virtalis, a virtual reality and visualization company, in collaboration with the British Geological Survey. It is specialist software for high-resolution 3D visualization and interpretation of geoscience data. Essentially, it brings geology and GIS together in a 3D computer environment. Thus far, mapping Irish karst features in this way has proven to be successful in certain areas of counties Roscommon, Monaghan and Cork.

Data dissemination – mobile and desktop applications

The GSI, is the national agency for geoscience, strives to produce up-to-date, high-resolution information to all stakeholders across Ireland. The ever-increasing availability of higher resolution digital information races to meet the growing demands of stakeholders

Figure 4 Mobile application. Image Credit: Shane Carey

and their specific management needs, especially through legislative requirements e.g., the Irish Environmental Protection Agency’s need for detailed sub-catchment scale information with respect to contaminant pathways to water bodies. However, collecting and interpreting high quality data is of little use to our stakeholders unless it is easily accessible and visible on a user-friendly interface.

Mobile application access

When developing the data dissemination applications, our main task was to produce an accessible interface that would reach as many end-users as possible. Hence, cross platform mobile applications were developed using the latest GIS company ESRI platforms – ArcGIS API for Javascript, along with desktop applications that use the latest Flash technology.

The mobile application (Groundwater mobile web app, Figure 4) was developed specifically for the Groundwater Programme and contains functionalities such as:

  • A choice of OSI (Ordnance Survey, Ireland) basemaps (Figure 5)
  • Geolocators
  • Switching on/off various groundwater layers (Figure 6)
  • Layer identify functionality
  • Displaying PDF reports for certain layers

This is an extremely useful on-site tool for field geologists, engineers, local authorities, agricultural consultants and hydrogeological consultants, to name just a few stakeholders. It also is used by the GSI groundwater field team when out on site. The application has an accompanying video tutorial guide (Figure 7) and since its launch in April 2015, the application has been used more than 700 times.

Desktop application access

The desktop application (groundwater viewer; Figure 8) was developed using the ArcGIS API for Flex (which is used to create GIS web applications) and comes with more expansive user functionality, including all the mobile application functionality, Irish Transverse Mercator (ITM) coordinate search, and the ability to print maps, upload shapefiles, extract data, and draw and measure.

Figure 8. Groundwater data viewer. Image Credit: Shane Carey

A move toward 3D

Moving from traditional 2D mapping to 3D modelling involves the acquisition of detailed topographic surface data (Lidar and bathymetry) and subsurface geologi

cal data (Figure 9). These data need to be standardized, interpreted and displayed in a meaningful way to the end-user. A number of software packages now available allow data to be represented in a succinct and purposeful way.

Some of the packages currently used by the GSI include ArcHydro for Hydrogeology, Geovisionary and GoCad. 3D models for specific regions of Ireland are being developed using these 3D software applications (Figure 9).

Figure 9. Bathymetry data of Lough Gur, Ireland. Image Credit: Shane Carey

Outreach – Twitter

The Groundwater Programme, a large part of which currently revolves around the GW3D project, involves a huge body of work from data collection to interpretation to data display and dissemination. A key part of the project involves communication with stakeholders and ensuring they receive the latest groundwater news. To follow the GSI’s groundwater mapping story and receive the latest news on data releases and mobile and desktop application updates, please follow us on Twitter @GsiGroundwater.

This article is published with the permission of the Director of the Geological Survey of Ireland, Koen Verbruggen.

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