Elevation-Derived Hydrography READ Rules: Connector: Indefinite Surface
A connector feature used where evidence of channelization is not present in the DEM surface but connectivity between an upstream and downstream channel is indicated by terrain modelling (Figure 47).
Introduction Continued...
Connector: Indefinite Surface features may be used include where the DEM is limited or where the channel is obscured in the DEM due to heavy vegetative cover (see the Delineating Features in Areas with DEM Limitation section). Connector: Indefinite Surface features can 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. Connector: Indefinite Surface may also be used to maintain the linear network through depressions in non-karst or thermokarst terrain (see Depressions under Special Cases).
Delineation
The limit of a Connector: Indefinite Surface 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 but resumes downstream. May be determined by modelling techniques, but a clearly defined channel shall not be found in locations where a Connector: Indefinite Surface is used. Connector: Indefinite Surface shall never be used in headwater locations. For indiscernible channels in headwater locations, see Drainageway.
Representation Rules
Delineate features as points, lines, or polygons based on their area or length along different axes (Table 24).
| Kind of feature object | Area | Shortest Axis | Longest Axis |
| 0-dimensional (point) | -- | -- | -- |
| 1-dimensional (line) | -- | greater than 0 | -- |
| 2-dimensional (polygon) | -- | -- | -- |
Special Conditions
None.
Data Extraction
Capture Conditions
Connector: Indefinite Surface features bridge gaps where a clearly defined channel is lost on the topographic surface but resumes downstream. Connector: Indefinite Surface features shall only be captured in locations with clearly defined channels upstream and downstream and shall have no discernible channel in between.
- A Connector: Indefinite Surface feature is used where a channel is not detectable (Appendix 3).
- If a section within a Connector: Indefinite Surface segment is within a channel on the elevation surface for more than 100 meters lidar (200 meters IfSAR), it shall be split and the section that is within a channel on the elevation surface shall be coded as a Stream/river, Canal/ditch, or other hydrographic features that may be within a channel on the elevation surface.
- Examples where Connector: Indefinite Surface features may be used include, but are not limited to:
- Areas with DEM Limitations or heavy vegetative cover where the channel cannot be resolved.
- Connector: Indefinite Surface 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.
- The Connector: Indefinite Surface feature type 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.
- If a feature does not have evidence of channelization, and is a headwater, the Drainageway feature type (FCode: 46800) shall be used.
- The Connector: Indefinite Surface feature type 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.
- Avoid using the Connector: Indefinite Surface feature type if karst terrain indicates underground flow is predominant and year-round (see Appendix 1 for Underground Conduit).
Attribute Information
FClass 1—Hydrography feature defined within the collection criteria of the elevation-derived hydrography specifications.
FCode 33404— Connector: Indefinite Surface (a connector feature used where evidence of channelization is not present in the DEM surface but connectivity between an upstream and downstream channel is indicated by terrain modelling).
EClass 2— Linear feature that follows elevation surface.
OR
FClass 1—Hydrography feature defined within the collection criteria of the elevation-derived hydrography specifications.
FCode 33404— Connector: Indefinite Surface (a connector feature used where evidence of channelization is not present in the DEM surface but connectivity between an upstream and downstream channel is indicated by terrain modelling).
EClass 0— Not used to create elevation derivatives.
Source Interpretation Guidelines
None.