A digital hydrologic unit boundary dataset for the State of Alabama at the Watershed (11-digit) level. The data consists of geo-referenced digital map data and attribute data, captured from 7 1/2 minute quadrangles to form a seamless layer for the entire state. It was developed by the organization SCIOPS and last updated on 1997-12-31.
Use Cases
- Delineating watersheds for environmental impact assessments based on the uniform subdivision of drainage areas.
- Supporting GIS applications for land management based on the seamless, state-wide polygon data layer.
- Linking land areas to attribute data for program planning based on the unique hydrologic unit ID codes.
Strengths
- Provides a seamless data layer covering the entire State of Alabama.
- All land area in the state is uniquely contained within one 11-digit hydrologic unit boundary.
- Hydrologic units are sized up to 250,000 acres, suitable for detailed analysis.
Limitations
- Last updated 1997 12 31 23:59:59.999000; freshness should be verified.
- Column-level documentation is absent; field semantics must be inferred after download.
- Row count is unknown, which may limit suitability assessment.
Provenance
- Source
- SCIOPS
- Collection Method
- Developed by delineating boundary lines on base maps and digitizing the delineated lines.
- Time Range
- 1997
- Freshness
- 1997-12-31 23:59:59.999000
- Geography
- State of Alabama