Elevation-Derived Hydrography READ Rules: Low-Confidence Area, Predetermined
Low-Confidence Area, Predetermined is a reference polygon used by the 3D Elevation Program (3DEP) to define an area where lidar penetration to the bare- earth surface is expected to be difficult to determine.
Use
These areas would be established prior to the collection and agreed upon by the data producer and the customer. Examples might include known areas of mangroves or triple-canopy tropical rainforest. Low-confidence areas may overlap other hydrographic features.
Attribute/Attribute Value
Each feature requires domain codes to be entered into the attribute table for the feature class (EDH Feature type description, associated geometry, and use classification table). See “Field Definitions and Domain Values for Attributes” section for more information on EDH code definitions.
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 11).
Special conditions: none.
Table 11. Low-confidence Area, Predetermined.
|
Kind of feature object |
Area |
Shortest Axis |
Longest Axis |
|
0-dimensional (point) |
-- |
-- |
-- |
|
1-dimensional (line) |
-- |
-- |
-- |
|
2-dimensional (polygon) |
greater than 0 |
-- |
-- |
Data Extraction
Capture Conditions
Established prior to the collection and agreed upon by the data producer and the customer.
Topology rules for adjacent features do not apply to low- confidence areas. For instance, they do not need to be snapped to adjacent features.
Attribute Information
FClass 9—Non-Hydrography Feature (elevation dataset limitation).
FCode 991—Low-confidence area (pre-determined).
EClass 9—Elevation dataset limitation.
Source Interpretation Guidelines
None.
