USGS: USGS TM 3-C4
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Title
| Guidelines and Procedures for Computing Time-Series Suspended-Sediment Concentrations and Loads from In-Stream Turbidity-Sensor and Streamflow Data Chapter 4 of Book 3, Applications of Hydraulics Section C, Sediment and Erosion Techniques |
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Author
| Rasmussen, P.P., Gray, J.R., Glysson, G.D., and Ziegler, A.C. |
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Abstract/Summary Statement
| In-stream continuous turbidity and streamflow data, calibrated with measured suspended-sediment concentration data, can be used to compute a time series of suspended-sediment concentration and load at a stream site. Development of a simple linear (ordinary least squares) regression model for computing suspended-sediment concentrations from instantaneous turbidity data is the first step in the computation process. If the model standard percentage error (MSPE) of the simple linear regression model meets a minimum criterion, this model should be used to compute a time series of suspended-sediment concentrations. Otherwise, a multiple linear regression model using paired instantaneous turbidity and streamflow data is developed and compared to the simple regression model. If the inclusion of the streamflow variable proves to be statistically significant and the uncertainty associated with the multiple regression model results in an improvement over that for the simple linear model, the turbidity-streamflow multiple linear regression model should be used to compute a suspended-sediment concentration time series. The computed concentration time series is subsequently used with its paired streamflow time series to compute suspended-sediment loads by standard U.S. Geological Survey techniques. Once an acceptable regression model is developed, it can be used to compute suspended-sediment concentration beyond the period of record used in model development with proper ongoing collection and analysis of calibration samples. Regression models to compute suspended-sediment concentrations are generally site specific and should never be considered static, but they represent a set period in a continually dynamic system in which additional data will help verify any change in sediment load, type, and source. |
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Table of Contents
| Abstract Introduction Types of Turbidity Sensors Relation of Turbidity to Suspended-Sediment Concentration Computation of Suspended-Sediment Concentration and Load Time-Series Record Summary Acknowledgments Selected References Appendix 1. Examples of Suspended-Sediment Concentration Models from Kansas, Oregon, Florida, and California Appendix 2. Computation, Storage, and Real-Time Display of Time-Series Suspended-Sediment Concentrations and Loads in National Water Information System Appendix 3. Comparison of Computed Suspended-Sediment Concentrations with Water-Quality Criteria |
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Citation
| Rasmussen, P.P., Gray, J.R., Glysson, G.D., and Ziegler, A.C., 2009, Guidelines and procedures for computing time-series suspended-sediment concentrations and loads from in-stream turbidity-sensor and streamflow data: U.S. Geological Survey Techniques and Methods book 3, chap. C4, 53 p. |
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Method Source
| USGS |
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Source Organization Country
| USA |
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Publication Year
| 2009 |
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Special Notes
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Item Type
| Report / Guidance Document |
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Publication Source Type
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Government Agency (Federal, USA) |
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Purpose
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Data analysis |
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Design or Data Analysis Objectives
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Compare locations Compliance with a threshold Continuous (sensor) data Derive thresholds Exploring/summarizing data Interpolate concentrations Loads & fluxes Probability survey Relationships & correlations Temporal trends Volume calculations |
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Complexity
| Medium |
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Media Emphasized
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Soils/Sediment Surface Water |
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Media Subcategory
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Special Topics
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Characterizing the uncertainty of an estimated value Evaluating whether data follow a certain (e.g., normal) distribution Identifying outliers Measurements taken using a water quality sensor |
