Learn about the 8-Digit HUCs Overlay, including the definition, benefits, tips, coverage and update frequency.
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Definition
The term "8-Digit HUCs" refers to a detailed classification system used in hydrology to identify and organize specific sub-watersheds or drainage areas within larger river basins. The Hydrologic Unit Code (HUC) system assigns unique codes to these hydrologic units, allowing for a hierarchical representation of watersheds.
In hydrology and water resource management, the Hydrologic Unit Code (HUC) system plays a crucial role in delineating and categorizing drainage basins across the United States. The system provides a structured framework for understanding and managing water-related processes at a localized level within a hierarchical watershed system.
The 8-digit version of these HUCs is the most commonly used resolution of this data. Each represents a more detailed subdivision within a larger hydrologic unit. Think of it as zooming in on a map of river basins to focus on specific sub-watersheds. Each 8-Digit HUC code is unique to a particular drainage area, allowing researchers, scientists and water resource managers to analyze and understand hydrologic characteristics at a finer resolution.
Key Benefits
This overlay is valuable for precise delineation of watersheds, facilitating detailed analyses in hydrology, water quality assessment and resource management.
Tip: Each HUC is labeled with it's name and 8-digit code
Limitation: These units were georeferenced and delineated at a scale of 1:24,000. Larger-scale zooming may reveal errors in precision. While it offers greater detail compared to coarser HUC levels, such as 2-digit or 4-digit, the 8-digit HUCs may still not capture all localized variations in hydrology and water management needs.
Coverage
Contiguous United States (exclude Hawaii and Alaska)
Update Frequency
As updates are available