Data file formats

This section provides an overview of the file formats supported by Source. Table 1 lists the supported time-series data file formats. Raster data file formats are listed in Table 2. Several GIS, graphics and other formats that are also recognised by Source are listed in Table 3 but are not otherwise described in this guide. Click on the link associated with each file extension to go directly to information about that time series.

Table 1. Text-based time-series data file formats

Table 2. Text-based raster data file formats

Table 3. Other supported file formats

Annual stochastic time series

The .AR1 format contains replicates of annual time-series data generated using the AR(1) stochastic method. The file format is shown in Table 4. This format is not the same as the AR(1) format (.GEN) generated and exported by the Stochastic Climate Library.

Table 4. AR1 data file format

where:

ESRI ASCII grids

The .ASC format is a space delimited grid file, with a 6 line header as shown in Table 5. Values are not case sensitive and arranged in space delimited rows and columns, reflecting the structure of the grid. Units for cell size length depend on the input data, and could be either geographic (eg degrees) or projected (eg metres, kilometres). Units are generally determined by the application, with metres (m) being common for most TIME-based applications. For a file format description, refer to:

http://resources.esri.com/help/9.3/arcgisengine/com_cpp/gp_toolref/spatial_analyst_tools/esri_ascii_raster_format.htm

Arcinfo grid coverages can be converted to .ASC files using ESRI’s GRIDASCII command. ASC files can be imported into ArcGIS using the ASCIIGRID command.

Table 5. .ASC data file format

where:

AWBM daily time series

An AWBM daily time series format file (.AWB) is an ASCII text file containing daily time series data formatted as shown in Table 6. Dates (the year and month) were optional in the original AWBM file format, but are not optional in the format used in Source.

Table 6. AWB data file format

where:

SWAT BSB time series

A .BSB is a line-based fixed-format file, typically used by applications written in FORTRAN. The SWAT BSB subbasin output file contains summary information for each of the subbasins in a watershed. The reported values for the variables are the total amount or weighted average of all hydrological response units (HRUs) within the subbasin. The format is shown in Table 7.  For more details, refer to the SWAT 2012 input/output manual (Arnold et al., 2012).

The .BSB file format specifies data time step numbers, but not dates. When imported into Source via File Data Sources, the user has the opportunity to manually set the correct data start date.

Table 7. .BSB data file format (first 7 data columns only). The .BSB format also includes an 8 line header, which is not shown.

where:

BOM 6 minute time series

A .BSM (also .PLUV) is a fixed-format file, typically supplied by the Australian Bureau of Meteorology for 6 minute pluviograph data. The file has two header lines (record types 1 and 2) followed by an arbitrary number of records of type 3. The formats of record types 1..3 are shown in Table 8, Table 9 and Table 10, respectively.

All fields in .BSM files use fixed spacing when supplied, but Source can also read spaced-separated values.

Rainfall data points:

• Each row of data contains all of the observations for that day;

• The number of observations for a day depends on the observation interval. For example, if the observation interval is 6 minutes, there will be 24×60÷6=240 observations (raini fields) in each row of data;

• Each rain field is in FORTRAN format F7.1 (a field width of seven bytes with one decimal place);

• Assuming that observations are numbered from 1..n, the starting column position of any given raini field can be computed from 14+7×i;

• The unit of measurement is tenths of a millimetre (eg. a rainfall of 2 mm will be encoded as "20.0").

• Values are interpreted as follows:

  • 0.0 means there was no rain during the interval.

  • a positive non-zero value is the observed rainfall, in tenths of a millimetre, during the interval.

  • If there is zero rain for the whole day, no record is written for that day.

Missing data:

• A sentinel value of -9999.0 means that no data is available for that interval;

• A sentinel value of -8888.0 means that rain may have fallen during the interval but the total is known only for a period of several intervals. This total is entered as a negative value in the last interval of the accumulated period. For example, the following the following pattern would show that a total of 2 millimetres of rain fell at some time during an 18-minute period: -8888.0-8888.0 -20.0

• If an entire month of data is missing, either no records are written or days filled with missing values (-9999.0) are written. No attempt is made to write dummy records if complete years of data are missing.

Example file

61078 1

61078 2 WILLIAMTOWN RAAF

61078 19521231 .0 .0 .0 [etc., 240 values]

61078 1953 1 1 .0 .0 .0 [etc., 240 values]

61078 1953 1 3 .0 .2 .0 [etc., 240 values]

61078 1953 115 .0 .0 .2 [etc., 240 values]

61078 1953 118 .0 .0 .0 [etc., 240 values]

61078 1953 212 .0 .0 .0 [etc., 240 values]

61078 1953 213 .0 .0 .0 [etc., 240 values]

61078 1953 214 .0 .0 .0 [etc., 240 values]

61078 19521231 .0 .0 .0 [etc., 240 values]

61078 19521231 .0 .0 .0 [etc., 240 values]

The following notes are taken from the Bureau of Meteorology advice:

• All data available in the computer archive are provided. However very few sites have uninterrupted historical record, with no gaps. Such gaps or missing data may be due to many reasons from illness of the observer to a broken instrument. A site may have been closed, reopened, upgraded or downgraded during its existence, possibly causing breaks in the record of any particular element.

• Final quality control for any element usually occurs once the manuscript records have been received and processed, which may be 6-12 weeks after the end of the month. Thus quality-controlled data will not normally be available immediately, in "real time".

Table 8. .BSM data file format (record type 1)

where:

Table 9. .BSM data file format (record type 2)

where:

Comma delimited time series

A .CDT comma delimited time-series format file is an ASCII text file that contains regular (periodic) time-series data. The file type commonly has no header line but, if required, it can support a single line header of "Date,Time series 1".

You can use the .CDT format to associate observations with a variety of time interval specifications. Table 10 shows how to structure annual data, Table 11 how to specify daily data aggregated at the monthly level, and Table 12 the more traditional daily time series (one date, one observation). Table 13 explains how to supply data in six-minute format.

Table 10. .CDT data file format (annual time series)

where:

Table 11. .CDT data file format (time series with monthly data)

where: