APDV:  Analyte Point Data File Format

Discussion of analyte (e.g. chemistry) or Property Files

Analyte (e.g. chemistry) or property files contain horizontal and vertical coordinates, which describe the 3-D locations and values of properties of a system. For simplicity, these files will generally be referred to in this manual as analyte (e.g. chemistry) files, although they can actually contain any scalar property value of interest. Analyte (e.g. chemistry) files must be in ASCII format and can be delimited by commas, spaces, or tabs. They must have a .apdv suffix to be selected in the file browsers of EVS modules .The content and format of analyte (e.g. chemistry) files are the same, except that fence diagram files require some special subsetting and ordering. Each line of the analyte (e.g. chemistry) file contains the coordinate data for one sampling location and any number of (columns of) analyte (e.g. chemistry) or property values. There are no computational restrictions on the number of borings and/or samples that can be included in a analyte (e.g. chemistry) file, except that run times for execution of kriging do increase with the number of samples in the file.

Analyte (e.g. chemistry) data can be visualized independently or within a domain bounded by a geologic system. When a geologic domain is utilized for a 3-D visualization, a consistent coordinate system must be used in both the analyte (e.g. chemistry) and geology files. The boring and sample locations in 3-D analyte (e.g. chemistry) files do not have to correspond to those in the geology files, except that they must be contained within the spatial domain of the geology, or they will not be displayed in the visualization. If the posting of borings and sample locations are to honor the topography of a site, the analyte (e.g. chemistry) files also must contain the top surface elevation of the boring. As will be described in later sections, EVS uses tubes to show actual boring locations and depths, and spheres to show actual sample locations in three-space. In order for these entities to be correctly positioned in relation to a variable topography, the top elevation of the boring must be supplied to the program.

Format:

• You may insert comment lines in .apdv files.

  • Comment lines must begin with a ’#’ as the first character of a line.

Line 1: You may include any header message here (that does not start with a ’#’ character) unless you wish to include analyte names for use by other EVS modules (e.g. data component name). The format for line 1 to enable chemical names is as follows

A. Placing a pair of ’@’ symbols triggers the use and display of chemical names (example @@VOC). Any characters up to the @@ characters are ignored, and only the first analyte name needs @@, after that the chemical names must be delimited by spaces,

B. The following rules for commas are implemented to accommodate comma delimited files and also for using chemical names which have a comma within (example 1,1-DCA). Commas following a name will not become a part of the name, but a comma in the middle of a text string will be included in the name. The recommended approach is to put a space before the names.

C. If you want a space in your analyte name, you may use underscores and EVS will convert underscores to spaces (example: Vinyl_Chloride in a .aidv file will be converted to ’r;Vinyl Chloride." Or you may surround the entire name in quotation marks (example: "Vinyl Chloride").

The advantages of using chemical names (attribute names of any type) are the following:

• • many modules use analyte names instead of data component numbers,

  • when writing EVS Field files (.eff, .efb, etc.), you will get analyte names instead of data component numbers.

  • when querying your data set with post_sample’s mouse interactivity, the analyte name is displayed.

  • time-series data can be used and the appropriate time-step can be displayed.

Line 2: Specifications

• Elevation/Depth Specifier: The first item on line 2 must be the word Elevation or Depth (case insensitive) to denote whether well screen top and bottom elevations are true elevation or depth below ground surface.
• Coordinate Units:After Depth/Elevation, include the units of your coordinates (e.g. feet or meters)

Line 3: Specifications

• The first integer (n) is the number of samples (rows of data) to follow. You may specify "All" instead to use all data lines in the file.
• The second integer is the number of analyte (chemistry) values per sample.
• The units of each data analyte column (e.g. ppm or mg/kg).

Line 4: The first line of analyte point data must contain:

• X

• Y

• Elevation (or Depth) of sample

• (one or more) Analyte Value(s) (chemistry or property)

• Well or Boring name.  The boring name cannot contain spaces (recommend underscore "_" instead).

• Elevation of the top of the boring.

Boring name and top are are optional parameters, but are used by many modules and it is highly recommended that you include this information in your file if possible. They are used by post_samples for posting tubes along borehole traces and for generating tubes which start from the ground surface of the borehole. Both 3d estimation and gridding and horizons will use this information to determing the Z spatial extent of your grids (gridding and horizons will create a layer that begins at ground surface if this information is provided). Numbers and names can be separated by one comma and/or any number of spaces or tabs.

BLANK ENTRIES (CELLS) ARE NOT ALLOWED.

 

Please see the section on Handling Non-Detects for information on how to deal with samples whose concentration is below the detection limit. For any sample that is not detected you may enter any of the following. Please note that thefirst threeflag words are not case sensitive, but must be spelled exactly as shown below.

• Prepend a less than sign < to the actual detection limit for that sample. This allows you to set the "Less Than Multiplier" in all modules that read .apdv files to a value such as 0.1 to 0.5 (10 to 50%). This is the preferred and most rigorous method.

• nondetect

• non-detect

• nd

• 0.0 (zero)

For files with multiple analytes such as the example below, if an analyte was not measured at a sample location, use any of the flags below to denote that this sample should be skipped for this analyte.Please note that these flag words are not case sensitive, but must be spelled exactly as shown below.

• missing

• unmeasured

• not-measured

• nm

• unknown

• unk

• na

Example Files are here: