Digital datasets were used to develop basin characteristics values that are used in multiple regression equations and tested for the use in predicting flow-duration curves (FDCs) in ungaged areas of Illinois. Several basin characteristics are easily derived from StreamStats basin delineations, such as basin area and basin centroid (https://streamstats.usgs.gov/ss/). Other basin characteristics require ancillary datasets as input. The data provided through this data release are those data that have been collected, tested, and ultimately selected as a basis for FDC development. These include Soil Components (Available Water Capacity, Drainage Index, and Permeability); PRISM 3-Month Average Precipitation; and Thickness and Coarseness of Quaternary Sediments.
There are 7 grids included in the Illinois portion of this data release: Soil Drainage index (drainind), PRISM December to February Average Precipitation (prdecfeb00), PRISM September to November Average Precipitation (prsepnov00), PermBXThick equation inputs (qss_permb and qss_thick), STATSGO Permeability (statsperm), and Available Water Capacity (watcapinil). NOTE: While previous versions are available from the author, all the records in previous versions can be found in version 3.0.
First posted - May 26, 2020 (available from author)
Revised - February 19, 2021 (version 2.0)
Revised - December 2, 2021 (version 3.0)