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Modeled and observed trends in streamflows at managed basins in the conterminous U.S. from October 1, 1983 through September 30, 2016

October 5, 2021

This data release contains trend results computed on the basis of modeled and observed daily streamflows at 1,257 gages across the conterminous U.S. from October 1, 1983 through September 30, 2016. Study gages were selected from the GAGES-II dataset of gages classified as non-reference which means streamflows may be affected by human influence. Modeled daily streamflows were computed using the deterministic Precipitation Runoff Modeling System (PRMS), and five statistical techniques: Nearest-Neighbor Drainage Area Ratio (NNDAR), Map-Correlation Drainage Area Ratio (MCDAR), Ordinary Kriging of the logarithms of discharge per unit area (OKDAR), Nearest-Neighbor nonlinear spatial interpolation using flow duration curves (NNQPPQ), and Map-Correlation nonlinear spatial interpolation using flow duration curves (MCQPPQ). Results include trends in annual means, annual percentiles (1, 5, 10, 25, 50, 75, 90, 95, 99), annual extremes (1-day high, 3-day high, and 7-day low). Bias and volumetric efficiency statistics between observed and modeled streamflows also are provided.