Cook Inlet Basin Study Unit – Glaciers

nawqa_glac1 is a polygon coverage of glaciers in the Cook Inlet National Water-Quality Assessment (NAWQA) study unit. The Cook Inlet NAWQA is located in southcentral Alaska and the coverage was created from 1:2,000,000 digital line graphs (DLGs). The purpose of nawqa_glac1 is to give a general overview of the amount of glaciers present in the Cook Inlet Basin. Because glaciers play an important part in the hydrology of rivers and streams, their absence or presence will be a critical factor in the selection of water-quality sampling sites for the Cook Inlet NAWQA.

The glacier coverage was created by USGS and Alaska Division of Natural Resources (ADNR) personnel using the USGS 1:2,000,000 digital line graphs (DLG) and techniques described by Domaratz and others (1982). Polygons representing glaciers were assigned a value of 40 to the item MAJ in the polygon attribute table. The drainage basin boundaries of the Cook Inlet Basin, developed from 1:250,000 quadrangle maps, were used as the boundaries of the coverage.