espam.precipitation

Conversion routines for ESPAM Tools

Contains conversion tools used for the ESPAM Tools. Currently only contains methods for converting PRISM files into a format usable by the ESPAM Tools.

class espam.precipitation.PreBuilder(settings)

Builder for PRE file format.

Creates a PRE file for input into MKMOD given processed PRISM precipitation data.

This class is a subclass of Builder

>>> buildPRE = PreBuilder(settings)
>>> buildPRE.generate_file("D:\out.pre")

generate_file(output_file)

Builds a PRE file from the input settings

Generates a PRE file, using the datasources from the settings.ini file:

• ESPA Model Grid Feature Class defined by the espagrid key
• Processed PRISM rasters defined by the prism key

See the PRE File Format document for more details on the PRE file format.

generate_file is a common method shared by all *Builder classes. The generate_file method always takes an output_file parameter, which is the location the file will be saved to. The settings used by generate_file are passed to the *Builder object in the constructor.

Parameters:	output_file (str) – Location to store output PRE file

espam.precipitation.batch_import_downloaded_prism(prism_download_dir, espa_grid_feature_class, out_dir)

Process a directory of PRISM files downloaded from the PRISM FTP Site.

Finds all GZipped files in the prism_download_dir and determines their Stress Period using the date embedded in the file name. Uses the prism_gzip_converter method to perform the imports. The file names should not be altered an any way from the names PRISM assigned to the files.

Parameters:	prism_download_dir (string) – Directory containing PRISM gz files downloaded from FTP site. espa_grid_feature_class (string) – Path to ESPA Model Grid GIS Dataset output_grid (string) – Directory to write the output processed grids to

espam.precipitation.prism_converter(prism_ascii_file, espa_grid_feature_class, output_grid)>

Converts Raw PRISM File Into A Format Usable For The ESPAM.Tools

The conversion process is as follows:

1. Imports PRISM ASCII File into an Esri Grid
2. Defines Projection Onto New Grid as NAD 83/Decimal Degrees
3. Projects PRISM Grid to IDTM 83
4. Clips PRISM Grid To ESPA Model Boundary
5. Resamples Grid Size To 500m x 500m
6. Converts Cell Values from 100’s of mm of rainfall to feet of rainfall

This tool requires a Spatial Analyst license to run.

Parameters:	prism_ascii_file (string) – Path to PRISM ASCII file espa_grid_feature_class (string) – Path to ESPA Model Grid GIS Dataset output_grid (string) – Path to output grid created by this function

espam.precipitation.prism_gzip_converter(prism_gzip_file, espa_grid_feature_class, output_grid)

Uncompresses a downloaded PRISM file and runs prism_converter

Uses Gunzip to uncompress a PRISM File, then runs the conversion process in the function prism_converter.

Parameters:	prism_gzip_file (string) – Path to GZipped PRISM file espa_grid_feature_class (string) – Path to ESPA Model Grid GIS Dataset output_grid (string) – Path to output grid created by this function