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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Research Project #436067

Research Project: Establishing Confidence Intervals and Error Bounds for the ISSDOTv2 Sand Bed Load Measurement Method

Location: Watershed Physical Processes Research

Project Number: 6060-13000-026-41-I
Project Type: Interagency Reimbursable Agreement

Start Date: Feb 1, 2019
End Date: Jun 30, 2020

Objective:
The main objective of the work is to validate the integrated section, surface difference over time, version 2 (ISSDOTv2) method of measuring bed load sediment transport in a range of conditions in a laboratory flume. The ISSDOTv2 method is used the U.S. Army Corps of Engineers to measure sand bed load in large rivers where physical sampling is difficult or impossible due to depth and flow conditions. Confidence intervals will be established from comparison to independent measurements of sediment transport, and the effect of unsteady flow conditions on the method will be assessed.

Approach:
A recirculating laboratory flume will be used to create flow conditions that result in a wide range of bed load sand transport rates. A 64-transducer acoustic bed mapping system will be used to collect detailed topographic data from which bed load will be calculated using the integrated section, surface difference over time, version 2 (ISSDOTv2) method. The results from the ISSDOTv2 calculations will be compared to the independent measurements of bed load from an automated bed load trapping/weighing system in the flume. Confidence intervals on ISSDOTv2 transport estimates will calculated from the results of experiments with conditions that do not change with time. More complex experiments with conditions that change with time will be used to establish error bounds for the ISSDOTv2 in unsteady flow and spatially heterogeneous flow.