Field measurements of water column optical properties from the Kootenai River in northern Idaho, September 26-27, 2017, and similar data from several other rivers

Field measurements of various optical properties of the water column were acquired from a single location on the Kootenai River in northern Idaho, September 26-27, 2017, to support research on remote sensing of rivers, particularly estimation of water depth from passive optical image data. The field measurements included in this data release include several parameters measured with three different instruments. A WetLabs EcoTriplet multi-probe was used to measure the volume scattering coefficient (Beta) at 700 nm, the back-scattering coefficient (b_b) at 700 nm, chlorophyll concentration, colored dissolved organic matter (CDOM) concentration, and turbidity. A Sequoia Scientific LISST-100X was used to measure the total mass concentration of suspended sediment and the particle size distribution of that sediment. A WetLabs ac-s was used to measure spectra of the beam absorption (a) and beam attenuation (c) coefficients at 81 wavelengths from 399.6-746.5 nm. All measurements were made from a dock at the Kootenai Tribal Fish Hatchery near Bonners Ferry, ID, by lowering each sensor into the water in turn. Each instrument was allowed to measure a time series of data for 2-3 minutes and the values reported in this data release are time averages over the entire sample duration. The coordinates of the measurements are included in the files comprising this data release and are in the UTM Zone 11N projection and NAD83 datum, with units of meters. Software provided by the manufacturer of each instrument was used to control the sensor in the field, record data to a computer, and export the raw data. Additional data processing (i.e., organization, plotting, and time averaging) was completed using custom functions developed in MATLAB. This data release consists of .csv files with the time-averaged values of each optical parameter; please see the metadata for further information on these files. This field-based data set played a valuable role in developing improved methods for mapping river bathymetry from remotely sensed data and understanding the limitations of spectrally based depth retrieval. In addition to these measurements from the Kootenai River, this data release includes a compilation of similar optical field data from several other rivers where studies have been conducted to develop methods for remote sensing of river bathymetry. These data were all collected using the methods and instruments described above for the Kootenai River and provide a database for evaluating the effects of water column optical properties on spectrally based depth retrieval. This compilation is provided in .csv data files and a Google Earth .kmz file with locations.

Tags: Blue River, California, Colorado, Colorado River, Deschutes River, Grand Teton National Park, Idaho, Kootenai River, Muddy Creek, Nebraska, Niobara River, Oregon, Sacramento River, Snake River, USDOI, USGS, Wyoming, absorption, attenuation, bathymetry, data.gov, depth, optical properties of water, remote sensing, rivers, scattering, suspended sediment, turbidity
Organization: United States Geological Survey