All of the data, queries and views are based on the following tables.
The first five tables are related to one another. The relationships between these tables are shown in the figure below.
The "Boring Data" table contains Boring IDs, x-y coordinates (Easting & Northing) and Top or ground surface elevation. This table might also contain boring or well construction details, contractor info, dates or other information.
Every chemical sample associated with a boring must also include the depth or Z coordinate, one or more analyte measurements (in this case, only total hydrocarbons). If depth is used, the Top or ground surface elevation must be available in A unique sample ID may also be associated with a sample or sample location (depth or elevation), however in this example, samples are identified (uniquely) by their boring ID and elevation.
The above three tables contain sufficient information to create a complete C Tech chemistry file. These same three tables could also be used to create a geology file representing ONLY the ground surface.
In order to create a true 3D geologic model, additional subsurface information must be provided. If none were available, a single geologic layer could still be created using ground surface and a constant elevation "floor" or constant depth for the bottom of the layer.
One way to create a true 3D geologic model or display all boring logs is using C Tech’s PGF (pre-geology file) format. The table below represents that information. Your corresponding table might also have material descriptors (e.g. sand, silt, etc.) in addition to the required Material ID.
Generally, a single layer (two surfaces) .geo or .gmf file is used when a .pgf file is used with Geologic Indicator Kriging to produce a 3D geologic model. This constrains the assignment of geologic materials to cells that lie between ground surface and the layer bottom vs. kriging into a "block" with flat top and bottom surfaces.
The table below contains additional subsurface depths. These depths represent surface position observations for the bottoms of 5 geologic layers relative to the ground surface at each boring location. This data has been organized according to C Tech’s geologic hierarchy. The data in this table can be used to create a .geo or a .gmf file.
C Tech’s .geo file format also provides for an optional column which contains a symbol number used to place a graphical symbol at the top of each boring, well or hydropunch. The table below contains that information.
In addition to tables that are a part of a relational database, information can be stored in tables that stand-alone, containing what is sometimes referred to as a "flat file". The table below represents such a file containing 273 samples for volatile organic compounds. Note that this table uses elevations (not depths) and does not include ground surface elevation information.
Similar to the table above, this table contains all required information to create the PGF file for a site in a single flat file.
