The HEM to NHDEvent XML Conversion Tool (HEM2XML) takes a Hydrography Event Management (HEM) created file geodatabase and exports the events to an Extensible Markup Language (XML) file that matches the Exchange Network hosted NHDEvent Exit schema format. The tool also compresses the XML file for efficient Exchange Network submission.

Changelog

Version: 3.0.1 - Released: February 05, 2019

• Corrected toolbar installation issue.

Version: 3.0 - Released: February 01, 2019

• Version 3.0 released for use with ArcGIS v10.5.1.
• The previous versions of the HEM2XML Tool were archived but are available for download by request to waters_support@epa.gov.

Version: 2.1 - Released: April 15, 2013

• Version 2.1 released for use with ArcGIS v10.1. The release also includes revisions noted in release v2.0.

Version: 2.0 - Released: April 15, 2013

• Version 2.0 released for use with ArcGIS v10.0. The release also includes revisions noted in release v1.2.2.
• The xml output file was restructured to mirror USGS NHD Event Model v2.1.
• A validation check was added to ensure the Permanent_Identifier field contains a unique value and valid Global Unique Identifier (GUID).
• A validation check was added to ensure the Meta_ProcessID field in the HEMMetadata table has a unique value and uses a valid GUID format.
• A validation check was added to ensure the Source_DatasetID field in the HEMSourceCitation table has a unique value and uses a valid GUID format.
• A validation check was added to ensure the Meta_ProcessID field in the HEMSourceCitation table uses a valid GUID format.
• The Meta_ProcessID and Permanent_Identifier together comprise the primary key for the HEMFeatureToMetadata table. Checks were added to validate that neither value is null, both values must be proper GUIDs and their combination must be unique.

Version: 1.2.2 - Released: April 15, 2013

• Removed the reached multi-string restriction on line events. Previously the occurrence of reached multi-strings prevented the XML from being generated. Multi-string geometries will be corrected using backend scripting.
• A header tag was added to indicate the EventType.

Version: 1.2.1 - Released: March 9, 2012

• This is a patch to Version 1.2 to allow the submission of multi-string custom line events with the specific condition: REACHCODE = null AND FMEASURE=null AND TMEASURE=null. In Version 1.2, this custom event should have been written to the the XML output but instead was rejected and cancelled the process of building the XML. Version 1.2.1 can be installed over Version 1.2.

Version: 1.2 - Released: January 17, 2012

• The user input form was altered to include three optional input fields (Cycle_Year, Start_Date, End_Date). These fields allow a user to provide standardized dates for an entire submission by overriding the feature level equivalent attributes.
• Added the ability to create a subset of data for submission to the CDX. This functionality is available on a tab on the input form.
• Added support for the Multipoint feature type.
• Since the HEM Tool does not currently support curves, the HEM2XML Tool was updated to provide an alert message to users when a submission contains features that contain curves. The alert message displays information about the feature id containing the curve.
• Multi-string reached events are rejected unless they are custom events. If a multi-string is encountered, the build of the XML is cancelled and an alert message is provided regarding the error and feature id.
• Links to help documentation have been added to the Tool.
• Suppressed the Byte Order Mark when creating xml output file to provide greater flexibility with CDX code changes.
• Software and tool version information is now recorded in the generated XML file to support server-side debugging activities.
• Corrected the way the gml srsName tag is written for NAD83 data from "EPSG:4269" to "urn:ogc:def:crs:OGC::CRS83" for coordinates written in LONGITUDE LATITUDE order.

Version: 1.1 - Released: February 28, 2011

• Empty feature tables are now properly handled by the tool. The tables will be ignored when writing the XML file.
• The feature count totals have been corrected in the XML header file when building consecutive files.
• A validation check was added to verify that the HEMFeatureToMetadata record count is greater than or equal to the sum of feature records.
• A validation check was added to check that the EPSG (European Petroleum Survey Group) code is not 0. If the code is 0 because the Spatial Reference name is "Longitude / Latitude [NAD 83]" or "NAD83" as defined using an Oracle SRID, this is replaced with the EPSG code 4269 when writing the file.
• Multipart lines are now supported.
• The tool dialog now closes on a successful build. If the process is cancelled or errors out, the dialog remains open and the Cancel button changes to Close.

Version: 1.0 - Released: August 31, 2010

• Initial release of the tool
• Follows the USGS 2.0 Event model
• Compatible with HEM 2.2