Elevation-Derived Hydrography READ Rules: Connector: Indefinite Surface
A Connector: Indefinite Surface is a connector feature used where evidence of channelization is not present in the digital elevation model surface but connectivity between an upstream and downstream channel is indicated by terrain modelling.
Introduction Continued...
Situations where Indefinite Surface Connectors may be used include where the DEM is limited or heavy vegetative cover in which the channel cannot be resolved. Indefinite surface connector features may also be used to connect through areas having conservation treatments such as grassed waterways, which are designed to prevent soil erosion and the formation of channels. This FCode is recommended for use in situations where streams sink into the ground under low or normal flow conditions but would flow over the surface during high flow or flood conditions and connect to downslope hydrographic features.
Attribute/Attribute Value
Each feature requires domain codes to be entered into the attribute table for the feature class (Elevation-Derived Hydrography Feature type description, associated geometry, and use classification table in the Elevation-Derived Hydrography Data Acquisition Specifications 2023 revision A2). See “Field Definitions and Domain Values for Attributes” section for more information on Elevation-Derived Hydrography code definitions.
Delineation
The limit of an indefinite surface connector is the space needed for connectivity between an upstream segment of a natural topographic flow-path and the downstream portion of that flowpath, where the channel becomes indiscernible over a distance and then picks up again downstream. May be determined by modelling techniques, but a clearly defined channel should not be found in locations where an indefinite channel connector is used. Indefinite surface connectors should never be used in headwater locations. For indiscernible channels in headwater locations, see drainageway.
Representation Rules
When delineating a feature, it must be created with the appropriate geometry, either point, line, or polygon, which is determined by the size of the feature or the length along different axes of the feature (table 5).
Special conditions: none.
Table 5. Connector: Indefinite Surface Representation Rules.
| Kind of feature object | Area | Shortest Axis | Longest Axis |
| 0-dimensional (point) | -- | -- | -- |
| 1-dimensional (line) | -- | greater than 0 | -- |
| 2-dimensional (polygon) | -- | -- | -- |
Data Extraction
Capture Conditions
Indefinite surface connectors are used to bridge a gap cause where a clearly defined channel is lost on a topographic surface but picks up again downstream. Indefinite surface connectors should be captured only in locations with clearly defined channels upstream and downstream and should have no discernible channel.
Attribute Information
FClass 1—Hydrography feature defined within the collection criteria of the elevation-derived hydrography specifications.
FCode 33404— Indefinite Surface Connector (a connector feature used where evidence of channelization is not present in the digital elevation model surface but connectivity between an upstream and downstream channel is indicated by terrain modelling).
EClass 2— Linear hydrographic features that follow the elevation surface.
Source Interpretation Guidelines
None.
