Cook Inlet Basin Study Unit – Hydrologic Unit Boundaries

nawqa_huc is a polygon coverage of hydrologic unit boundaries within the Cook Inlet Basin National Water-Quality Assessment (NAWQA) study area in southcentral Alaska. A hydrologic unit is a region or area bounded by a drainage divide and occupied by a drainage system. Each hydrologic unit (drainage area) boundary and an 8-digit name (huc.code) is from the report U.S. Geological Survey, 1987, Hydrologic unit map-1987-State of Alaska: U.S. Geological Survey map, 1 sheet.

The purpose of this coverage is to define the extent and boundaries of drainage systems within the Cook Inlet Basin. The hydrologic unit boundaries were drawn on the 1:250000 paper quadrangle maps. The boundaries were then digitized and entered into ARC-INFO. Using ARC-EDIT procedures, the data were edited where appropriate and then combined into one coverage.