NHD Event Data Dictionary

The data structure of events in the RAD are largely patterned upon the event table format defined by the USGS NHD schema. Several tools now exist to create hydrologic events using the NHD standard and the RAD accepts events in this format. The following data dictionary is provided as an aid in understanding this format. Note that the cycle_year, start_date and end_date fields are not currently part of the USGS NHD schema but are vital in the submission of event data to the RAD.

NHD Point Event

Field Name
Data Type
NULL?
Description
Stored in RAD?

comid
NUMBER(11) N
Unique numeric identification number for the event. Note this value is not directly stored within the RAD event table but should be a logical unique identifier for the event in case RAD events need to be traced back to their data submission. This field is critical for the join to the metadata records and must be unique for a given event submission. All attempts should be made to create a unique identification number system that remains unique among all batches submitted.
Y

eventdate
DATE
Y
The date the event was created or updated.
Y

event_type
INTEGER
N
Value indicating the program for which the event has been created. See RAD Programs for values of each program. Y

reachcode
VARCHAR2(14)
Y
The reach code value of the NHD waterbody feature the event occurs upon. When submitting custom or nonstandard event types, this field may be left NULL.
Y

reachsmdate
DATE
Y
Date that the NHD reach code was assigned.
Y

reachresolution
INTEGER
N
Value indicating the resolution of the NHD waterbody feature the event occurs upon. See NHD Resolution Domain Table for the list of values.
Y

featurecomid
INTEGER
Y

N

featureclassref
INTEGER
Y

N

source_originator
VARCHAR2(30)
N
Abbreviated name of the organization submitting the event.
Y

source_datadesc
VARCHAR2(20)
Y
Attribute value being indexed.
Y

source_featureid
VARCHAR2(60)
Y
Foreign key to external program database. Y

featuredetailurl
VARCHAR2(99)
Y

Y

offset
NUMBER(12,7)
Y
Event display offset.
Y

measure
NUMBER(12,4)
N
Point measure that the event occurs at upon the reached flowline.
Y

cycle_year
DATE
Y
The cycle year of the event data being submitted. Not all programs have the cycle year concept. For those programs with a cycle year concept this field is mandatory. Convention is to use April 1st of the cycle year when storing the date value.
Y

start_date
DATE
N
The start date indicates the date on which the event becomes valid for the program. All program events must have a start date. For programs tracking this value only via year, use April 1st for month and day.
Y

end_date
DATE
N
The end date indicates the date on which the event is no longer valid or is superceded by new event data in a new record. For event submitters, this field will only be used when submitting historical data to be place directly into the RAD archive tables. Note that the majority of submissions will not utilize this field.
Y

rid
<geometry>
Y
Acceptable geometry data types include MDSYS.SDO_GEOMETRY, SDE.ST_GEOMETRY, BLOB of Geographic Markup Language (GML) 2.1, BLOB of Well-Known-Text (WKT) or Well-Known-Text binary format (WKB). Submissions using shapefiles or file geodatabases do not need to add this field. All geometries should utilize a NAD83 unprojected coordinate system or supply specific documentation on projection and datum used.
Y

objectid
INTEGER
N
Unique numeric key used by ArcSDE. Simply prefill with any unique integer.
Y

NHD Line Event

Field Name
Data Type
NULL?
Description
Stored in RAD?

comid
NUMBER(11) N
Unique numeric identification number for the event. Note this value is not directly stored within the RAD event table but should be a logical unique identifier for the event in case RAD events need to be traced back to their data submission. This field is critical for the join to the metadata records and must be unique for a given event submission. All attempts should be made to create a unique identification number system that remains unique among all batches submitted. Y

eventdate
DATE
Y
The date the event was created or updated.
Y

event_type
INTEGER
N
Value indicating the program for which the event has been created. See RAD Programs for values of each program. Y

reachcode
VARCHAR2(14)
Y
The reach code value of the NHD waterbody feature the event occurs upon. When submitting custom or nonstandard event types, this field may be left NULL.
Y

reachsmdate
DATE
Y
Date that the NHD reach code was assigned.
Y

reachresolution
INTEGER
N
Value indicating the resolution of the NHD waterbody feature the event occurs upon. See NHD Resolution Domain Table for the list of values. Y

featurecomid
INTEGER
Y

N

featureclassref
INTEGER
Y

N

source_originator
VARCHAR2(30)
N
Abbreviated name of the organization submitting the event. Y

source_datadesc
VARCHAR2(20)
Y
Attribute value being indexed.
Y

source_featureid
VARCHAR2(60)
Y
Foreign key to external program database. Y

featuredetailurl
VARCHAR2(99)
Y

Y

offset
NUMBER(12,7)
Y
Event display offset.
Y

fmeasure
NUMBER(12,4) N
Linear Reference starting measure.
Y

tmeasure
NUMBER(12,4)
N
Linear Reference ending measure.
Y

shape_length
NUMBER(12,4)
N
Length of linear event in meters.
Y

cycle_year
DATE
Y
The cycle year of the event data being submitted. Not all programs have the cycle year concept. For those programs with a cycle year concept this field is mandatory. Convention is to use April 1st of the cycle year when storing the date value. Y

start_date
DATE
Y
The start date indicates the date on which the event becomes valid for the program. All program events must have a start date. For programs tracking this value only via year, use April 1st for month and day. Y

end_date
DATE
Y
The end date indicates the date on which the event is no longer valid or is superceded by new event data in a new record. For event submitters, this field will only be used when submitting historical data to be place directly into the RAD archive tables. Note that the majority of submissions will not utilize this field.
Y

rid
<geometry>
Y
Acceptable geometry data types include MDSYS.SDO_GEOMETRY, SDE.ST_GEOMETRY, BLOB of Geographic Markup Language (GML) 2.1, BLOB of Well-Known-Text (WKT) or Well-Known-Text binary format (WKB). Submissions using shapefiles or file geodatabases do not need to add this field. All geometries should utilize a NAD83 unprojected coordinate system or supply specific documentation on projection and datum used.
Y

objectid
INTEGER
N
Unique numeric key used by ArcSDE. Simply prefill with any unique integer.
Y

NHD Area Event

Field Name
Data Type
NULL?
Description
Stored in RAD?

comid
NUMBER(11) N
Unique numeric identification number for the event. Note this value is not directly stored within the RAD event table but should be a logical unique identifier for the event in case RAD events need to be traced back to their data submission. This field is critical for the join to the metadata records and must be unique for a given event submission. All attempts should be made to create a unique identification number system that remains unique among all batches submitted. Y

eventdate
DATE
Y
The date the event was created or updated.
Y

event_type
INTEGER
N
Value indicating the program for which the event has been created. See RAD Programs for values of each program. Y

reachcode
VARCHAR2(14)
Y
The reach code value of the NHD waterbody feature the event occurs upon. When submitting custom or nonstandard event types, this field may be left NULL.
Y

reachsmdate
DATE
Y
Date that the NHD reach code was assigned.
Y

reachresolution
INTEGER
N
Value indicating the resolution of the NHD waterbody feature the event occurs upon. See NHD Resolution Domain Table for the list of values. Y

featurecomid
INTEGER
Y

N

featureclassref
INTEGER
Y

N

source_originator
VARCHAR2(30)
N
Abbreviated name of the organization submitting the event. Y

source_datadesc
VARCHAR2(20)
Y
Attribute value being indexed.
Y

source_featureid
VARCHAR2(60)
Y
Foreign key to external program database.
Y

featuredetailurl
VARCHAR2(99)
Y

Y

shape_area
NUMBER(18,3)
N
Area of the event in square kilometers.
Y

cycle_year
DATE
Y
The cycle year of the event data being submitted. Not all programs have the cycle year concept. For those programs with a cycle year concept this field is mandatory. Convention is to use April 1st of the cycle year when storing the date value. Y

start_date
DATE
Y
The start date indicates the date on which the event becomes valid for the program. All program events must have a start date. For programs tracking this value only via year, use April 1st for month and day. Y

end_date
DATE
Y
The end date indicates the date on which the event is no longer valid or is superceded by new event data in a new record. For event submitters, this field will only be used when submitting historical data to be place directly into the RAD archive tables. Note that the majority of submissions will not utilize this field.
Y

rid
<geometry>
Y
Acceptable geometry data types include MDSYS.SDO_GEOMETRY, SDE.ST_GEOMETRY, BLOB of Geographic Markup Language (GML) 2.1, BLOB of Well-Known-Text (WKT) or Well-Known-Text binary format (WKB). Submissions using shapefiles or file geodatabases do not need to add this field. All geometries should utilize a NAD83 unprojected coordinate system or supply specific documentation on projection and datum used.
Y

objectid
INTEGER
N
Unique numeric key used by ArcSDE. Simply prefill with any unique integer. Y

NHD Feature to Metadata

Field Name
Data Type
NULL?
Description
Stored in RAD?

comid
NUMBER(11)
N
Unique numeric identification number for the event. Note this value is not directly stored within the RAD event to metdata table but should be a logical unique identifier for the event in case RAD events need to be traced back to their data submission.
Y

duuid
NUMBER(11)
N
Unique numeric identification number for the metadata record. Note this value is not directly stored within the RAD event to metdata table but should be a logical unique identifier for the metadata in case RAD events need to be traced back to their data submission. Y

NHD Metadata

Field Name
Data Type
NULL?
Description
Stored in RAD?

duuid
NUMBER(11)
N
Unique numeric identification number for the metadata record. Note this value is not directly stored within the RAD metadata table but should be a logical unique identifier for the metadata in case RAD events need to be traced back to their data submission. Y

processdescription
VARCHAR2(4000)
N
Process used to create the event data.
Y

processdate
DATE
N
Date the event data was processed.
Y

attributeaccuracyreport
VARCHAR2(1800)
Y
Attribute accuracy of event data.
N

logicalconsistencyreport
VARCHAR2(1000)
Y
Logical consistency of event data.
N

completenessreport
VARCHAR2(2400)
Y
Completeness description of event data.
N

horizpositionalaccuracyreport
VARCHAR2(3100)
Y
Horizontal positional accuracy of event data.
N

vertpositionalaccuracyreport
VARCHAR2(3100)
Y
Vertical positional accuracy of event data.
N

metadatastandardname
VARCHAR2(100)
Y
Metadata standard name.
N

metadatastandardversion
VARCHAR2(30)
Y
Metadata standard version.
N

metadatadate
DATE
Y
Date metadata records was created or modified.
N

datasetcredit
VARCHAR2(4000) Y

N

contactorganization
VARCHAR2(100)
Y
Name of the organization responsible for the metadata record.
Y

addresstype
VARCHAR2(40) Y
Type of address given (mail/physical).
Y

address
VARCHAR2(100)
Y
Address of contact person.
Y

city
VARCHAR2(40)
Y
City of contact person.
Y

stateorprovince
VARCHAR2(30)
Y
State of contact person.
Y

postalcode
VARCHAR2(20)
Y
Zip Code or Postal Code of contact person.
Y

contactvoicetelephone
VARCHAR2(40)
Y
Voice phone number of contact person.
Y

contactinstructions
VARCHAR2(120)
Y

Y

contactemailaddress
VARCHAR2(40)
Y
Email Address of contact person.
Y

NHD Reach Resolution Domain Table

Value
Description

1
Local Resolution

2
High Resolution

3
Medium Resolution

Field Name	Data Type	NULL?	Description	Stored in RAD?
comid	NUMBER(11)	N	Unique numeric identification number for the event. Note this value is not directly stored within the RAD event table but should be a logical unique identifier for the event in case RAD events need to be traced back to their data submission. This field is critical for the join to the metadata records and must be unique for a given event submission. All attempts should be made to create a unique identification number system that remains unique among all batches submitted.	Y
eventdate	DATE	Y	The date the event was created or updated.	Y
event_type	INTEGER	N	Value indicating the program for which the event has been created. See RAD Programs for values of each program.	Y
reachcode	VARCHAR2(14)	Y	The reach code value of the NHD waterbody feature the event occurs upon. When submitting custom or nonstandard event types, this field may be left NULL.	Y
reachsmdate	DATE	Y	Date that the NHD reach code was assigned.	Y
reachresolution	INTEGER	N	Value indicating the resolution of the NHD waterbody feature the event occurs upon. See NHD Resolution Domain Table for the list of values.	Y
featurecomid	INTEGER	Y		N
featureclassref	INTEGER	Y		N
source_originator	VARCHAR2(30)	N	Abbreviated name of the organization submitting the event.	Y
source_datadesc	VARCHAR2(20)	Y	Attribute value being indexed.	Y
source_featureid	VARCHAR2(60)	Y	Foreign key to external program database.	Y
featuredetailurl	VARCHAR2(99)	Y		Y
offset	NUMBER(12,7)	Y	Event display offset.	Y
measure	NUMBER(12,4)	N	Point measure that the event occurs at upon the reached flowline.	Y
cycle_year	DATE	Y	The cycle year of the event data being submitted. Not all programs have the cycle year concept. For those programs with a cycle year concept this field is mandatory. Convention is to use April 1st of the cycle year when storing the date value.	Y
start_date	DATE	N	The start date indicates the date on which the event becomes valid for the program. All program events must have a start date. For programs tracking this value only via year, use April 1st for month and day.	Y
end_date	DATE	N	The end date indicates the date on which the event is no longer valid or is superceded by new event data in a new record. For event submitters, this field will only be used when submitting historical data to be place directly into the RAD archive tables. Note that the majority of submissions will not utilize this field.	Y
rid	<geometry>	Y	Acceptable geometry data types include MDSYS.SDO_GEOMETRY, SDE.ST_GEOMETRY, BLOB of Geographic Markup Language (GML) 2.1, BLOB of Well-Known-Text (WKT) or Well-Known-Text binary format (WKB). Submissions using shapefiles or file geodatabases do not need to add this field. All geometries should utilize a NAD83 unprojected coordinate system or supply specific documentation on projection and datum used.	Y
objectid	INTEGER	N	Unique numeric key used by ArcSDE. Simply prefill with any unique integer.	Y

Value	Description
1	Local Resolution
2	High Resolution
3	Medium Resolution