3D Hydrography Program 3DHP_all: Flowline

id3dhp

Unique identifier for 3DHP features.

Text

Yes

7

-

-

This is a base-36 7-digit alphanumeric unique identifier that is not persistent. 

Applied to hydrolocation features in this case.

featuredate

Date the feature was loaded into the 3DHP core database.

Date

Yes

-

-

-

-

mainstemid

A cross-dataset identifier for all flowlines that represent the headwater to outlet path of a river.

Text

Yes

200

-

-

A mainstem is equivalent to a feature with the same levelpathid in NHDPlus HR.

The text field will be a <geoconnex.us>*.

gnisid

A permanent, unique number assigned by the Geographic Names Information System (GNIS)**

to a geographic feature name for the sole purpose of uniquely identifying that name.

Long Integer

Yes

-

-

-

gnisid = "null" if no name is associated with the feature. The gnisid is conflated

from points and assigned to features. The most recent name, and any historic names,

can be retrieved from the GNIS data base using the gnisid.

featuretype

Feature type description.

Short Integer

Yes

-

flowline

feature

type

-

-

featuretypelabel

The name of the feature type.

Text

Yes

50

-

-

The featuretype label is based on the coded value description in the featuretype field.

Allows label display in non-ESRI datasets.

lengthkm

Length of linear flowline feature. Value based on regional spatial reference systems.

Double

Yes

 -

 -

 -

Computed in projections based on specific locations, please see the Spatial Reference

System Section of this specification for more information.

waterbodyid3dhp

The id3dhp of the waterbody that a waterbody connector flows through.

Text

Yes

7

 -

 -

flowdirection

Identifies the flow direction of a feature relative to the direction it was digitized.

Short Integer

No

 -

Flow

direction

type

1

 -

onsurface

Defines vertical relationship of flowline features.

Short Integer

No

 -

Onsurface

type

1

Indicates whether the flowline feature is on the land surface, below the surface, or elevated

above the ground and another hydrography feature.

1

River

Flowing body of water that receives inflow from upstream and surrounding catchment.

Yes

In elevation-derived hydrography a River is a feature that is delineated

within elevation-surface channelization.

2

Canal

Flowing body of water that receives inflow from upstream but not the surrounding catchment.

No

Integrated with elevation but not thought to integrate with surrounding

hydrology in most cases.

3

Drainageway

Drainage pathway in a low drainage area setting (headwater) upstream of the onset of

discernable channelization.

No

-

4

Surface Connector

Abstract surface or near surface path used to connect upstream channelized features with

downstream channelized features.

Yes

 In elevation-derived hydrography a Surface Connector is a feature that is

delineated where there is no elevation-surface channelization.

5

Waterbody Connector

Abstract connector over a portion of the landscape covered by water.

Yes

-

6

Elevation Breaching Connector

A known or inferred connection that is used to breach values in the elevation surface that are

blocking the natural downstream flow of a hydrologic feature.

Yes

Culverts across transportation features are the most common occurrence.

7

Hydro Unenforced Connector

Specific or abstract connector representing flow that is not determined by the surface-water

hydrologic network.

No

Most pipelines and underground flowpaths through karst terrain are included

here.

0

Flow direction is unable to be determined from elevation surface

1

Flow direction is in digitized direction, and z-values on vertices flow downslope

2

Flow direction is in digitized direction, and z-values on vertices flow upslope

0

Feature is above another hydrography feature, elevated above the surface

1

Feature is on the land surface

2

Feature is below the land surface

id3dhp

Unique identifier for identified 3DHP flowline feature.

Text

No

7

-

-

This is a base-36 7- digit alphanumeric unique identifier that is not persistent.

catchmentid3dhp

Unique identifier of catchment for catchment aggregation

Text

No

7

-

-

All hydro-enforced flowlines within an aggregate catchment will be identified

in catchmentid3dhp. Flowlines that are not hydro-enforced will not be associated

with a catchment and the catchmentid3dhp will be NULL.

flowpathid3dhp

Unique identifier of catchment for flowpath aggregation.

Text

Yes

7

-

-

Identifies the flowlines along the main path of a catchment. Flowlines within a

catchment that are not on the mainstem path will have a NULL flowpathid3dhp.

streamlevel

StreamLevel is a numeric code that traces main paths of

water flow upstream through the drainage network.

Long Integer

Yes

-

-

-

StreamLevel should be constant for a mainstemid. StreamLevel increase from

downstream to upstream.

startflag

Startflag is used to differentiate headwater features from

non-headwater features.

Short Integer

Yes

0

logical

-

Set to true if the flowline feature is a headwater according to the flownetwork table,

otherwise false.

terminalflag

Terminalflag is used to differentiate terminal flow features

from non-terminal flow features.

Short Integer

Yes

0

logical

-

Set to true if the flowline feature is a terminal feature (flows into ocean, Great Lakes,

Canada, Mex. or the ground) otherwise set to false.

streamorder

Strahler stream order number for the flowline feature.

Long Integer

Yes

-

-

-

Streamorder does not increment when a path emanating from a diversion joins a

main path.

streamcalculator

Further modification of streamorder created to assist with

tracking divergences and is computed with streamorder.

Long Integer

Yes

-

-

-

Streamcalculator is assigned the value 0 along diverted paths.

hydrosequence

Nationally unique sequence number that places the reach in

hydrologic sequence.

Double

Yes

-

-

-

If a path exists between two flowlines, the upstream flowline will have a larger hydrosequence

value. If no path exists between the flowlines, hydrosequence has no significance. Hydrosequence

is equivalent to a topological sort of the dendritic network.

dnhydrosequence

Downstream mainstem hydrologic sequence number.

Double

Yes

-

-

-

-

uphydrosequence

Upstream mainstem hydrologic sequence number.

Double

Yes

-

-

-

-

levelpath

Hydrologic sequence number of the most downstream flowline

feature that is on the same StreamLevel path as this flowline

feature according to the flownetwork table.

Long Integer

Yes

-

-

-

-

uplevelpath

Levelpath identifier of the feature on the main path immediately

upstream.

Double

Yes

-

-

-

-

dnlevelpath

Levelpath identifier of the feature on the main path immediately

downstream.

Double

Yes

-

-

-

-

pathlength

Distance to terminal flowline feature downstream along main path

in kilometers using an equal area projection.

Double

Yes

-

-

-

Computed in projections based on specific locations, please see the Spatial Reference System

Section of this specification for more information

terminalpath

Hydrologic sequence number of terminal flowline of the basin the

feature is in.

Double

Yes

-

-

-

-

arbolatesum

The sum of the lengths of every upstream feature in the flownetwork,

as well as the length of the current feature.

Double

Yes

-

-

-

-

divergence

Indicates if a flowline feature is a diversion based on the divergencetype.

Short Integer

Yes

0

divergence

type

-

-

rtrndivergence

Indicates that one or more of the paths contributing to a given flowline

originates in a divergence that recombines with its main path at the current flowline.

Short Integer

Yes

0

logical

-

Set to true if flowline feature is a return divergence, otherwise false.

0

No divergence

1

Main path through a divergence

2

Minor path through a divergence