DOI: 10.48443/eaak-tt31
title: Discharge field collection (DP1.20048.001)
title: RELEASE-2022

description: This data product contains the quality-controlled, native sampling resolution data from NEON's stream and river discharge field collection protocol. Individual discharge measurements are conducted by means of surveys that occur in wadeable streams and rivers along permanently benchmarked cross-sections at NEON aquatic sites.  At the Toolik Lake site discharge is measured at the lake outflow and inflow locations.  At stream sites (and Toolik Lake inflow and outflow), discharge is measured using a handheld flowmeter (when flows are very low) and acoustic Doppler current profiler (ADCP) instrumentation (when flows are at or above baseflow).  During flowmeter measurements the waterbody is divided into lateral sub-sections (of which there are typically 20-25 per cross-section). Within each subsection, an instantaneous velocity magnitude is obtained via a handheld flowmeter and transformed to a volumetric discharge magnitude by applying the velocity across the full subsection area. Total stream discharge is then calculated by summing the discrete volumetric discharges for each subsection.  During ADCP measurements the ADCP is placed in a trimaran float and pulled back and forth across the channel using a tethered rope system.  Velocity, depth, and area data are continuously measured, and discharge is calculated for each transect.  Total discharge for a given bout is the mean discharge across all transects.  At river sites discharge is measured using ADCPs deployed in remote controlled boats that are driven back and forth across the channel.  Discharge is calculated in the same manner as the ADCP method at stream sites, only the deployment method differs.  If remote controlled boats are not available a piloted boat method serves as a backup where the ADCP is deployed off the side of a piloted boat.  
For additional details, see the user guide, protocols, and science design listed in the Documentation section in this data product's details webpage. 

Latency:
The expected time from data and/or sample collection in the field to data publication is as follows, for each of the data tables (in days) in the downloaded data package. See the Data Product User Guide for more information.

dsc_fieldData:  30

dsc_individualFieldData:  30

dsc_individualFieldDataADCP:  30
description: Discharge is measured in all wadeable stream and river sites as well as the Toolik lake inflow and outflow. At stream sites and the Toolik Lake inflow and outflow, field collection measurements are made 24 times per year until a valid stage-discharge relationship, i.e. rating curve, is developed. Once a relationship has been established, measurements will be made 12 times per year to verify the rating curve and identify when a new stage-discharge relationship may need to be developed. Discharge field collections will be planned to capture the range of discharge values for a particular location. At some sites this may mean relatively evenly timed surveys, e.g. every two weeks during stage-discharge relationship development, while at others the surveys may be concentrated during variable-flow times of year, e.g. spring snow-melt, with less frequent surveys during baseflow times of year.  At river sites discharge is measured 12 times per year across a range of stage levels. Instrumentation: HACH FH950 (wadable stream sites + Toolik Lake inflow/outflow), Teledyne Stream Pro ADCP (wadable stream sites + Toolike Lake inflow/outflow), Teledyne River Pro ADCP (river sites)