Conus-wide Analysis of Manning's n Values

The datasets utilized in this study were derived from extensive global research initiatives. Specifically, the United States Geological Survey (USGS) compiled HYDRoSWOT, an assemblage of HYDRoacoustic data supporting the Surface Water Oceanographic Topography satellite mission. This compilation encompasses over 200,000 Acoustic Doppler Current Profiler (ADCP) surveys conducted at numerous sites throughout the United States.

The MODIS instrument, situated on the Terra and Aqua satellite missions, generated the MOD13Q1 V6.1 product, offering information on the Normalized Difference Vegetation Index (NDVI). This product serves as a continuity index to the pre-existing National Oceanic and Atmospheric Administration-Advanced Very High-Resolution Radiometer (NOAA-AVHRR) derived NDVI. Sand and clay content data were acquired as percentages (kg/kg) at six standard depths (0, 10, 30, 60, 100, and 200 cm); however, only depths of 0 and 10 cm were considered in this investigation.

The Aridity Index (AI), depicting the ratio between precipitation and evapotranspiration aggregated annually, was sourced from the Global Aridity Index Version 2 dataset. This dataset provides high-resolution global raster climate data pertaining to evapotranspiration processes and rainfall deficit for potential vegetative growth.

Slope information was determined utilizing the National Hydrography Dataset version 2 (NHDPlus V2) and subsequently averaged for each reach. Additionally, the median streambed particle size (D50) across rivers within the conterminous United States (CONUS) was incorporated as an input variable in the analysis.