THE ONTARIO GEOLOGICAL SURVEY'S SURFICIAL AQUIFER MAPPING PROGRAM; PRODUCTS AND VISUALIZATION TOOLS

The Ontario Geological Survey's (OGS) surficial aquifer mapping program is part of a broader OGS initiative designed to provide basic geoscience information for the identification, protection, preservation and sustainable use of the provincial groundwater resource. Three-dimensional (3-D) mapping of surficial deposits involves the characterization of the geometry and inherent properties of aquifers and aquitards overlying bedrock. This information can 1) aid in studies involving groundwater identification, extraction, protection and remediation; 2) assist with the development of policies surrounding land use and nutrient management; and 3) help to better understand the interaction between surface and groundwater systems. The results of these projects are being released on CD-ROM as a series of Groundwater Resources Studies. The reports briefly summarize the geology, provide an in depth discussion of the procedures and protocols involved in the construction of the 3-D geologic models and contain a brief discussion of the geometry and properties of the main hydrostratigraphic units modelled. Structural contour and isopach maps, cross sections spaced at 2.5 km intervals and depth to aquifer maps that can be used to assess aquifer vulnerability and recharge accompany the reports. Companion digital data sets are also released on CD-ROM with the Groundwater Resources Studies. They consist of 1) portable document format (PDF) versions of all cross-sections and maps listed above; 2) comma delimited text files of modelled surfaces on a 100 m grid; 3) 100 m ArcInfo® structural contour grids of discontinuous surfaces; 4) abridged versions of the subsurface databases used for the construction of the 3-D models that contain borehole location and stratigraphic information; 5) a beta cross-section viewer capable of drawing and saving sections along lines drawn on a Microsoft® Windows® Virtual Earth™ base map; and 6) a .kmz file that portrays fence diagrams, transparent overlays of the structural contour, isopach and aquifer recharge/susceptibility maps as well as borehole location and lithologic information in a web-based (Google™ Earth) environment. This functionality allows for enhanced user interaction with the spatial data.