| Abstract: | Optimal estimators are developed for computation of suspended-sediment concentrations in streams. The estimators are a function of parameters, computed by use of generalized least squares, which simultaneously account for effects of streamflow, seasonal variations in average sediment concentrations, a dynamic error component, and the uncertainty in concentration measurements. The parameters are used in a Kalman filter for on-line estimation and an associated smoother for off-line estimation of suspended-sediment concentrations. The accuracies of the optimal estimators are compared with alternative time-averaging interpolators and flow-weighting regression estimators by use of long-term daily-mean suspended-sediment concentration and streamflow data from 10 sites within the United States. For sampling intervals from 3 to 48 days, the standard errors of on-line and off-line optimal estimators ranged from 52.7 to 107%, and from 39.5 to 93.0%, respectively. The corresponding standard errors of linear and cubic-spline interpolators ranged from 48.8 to 158%, and from 50.6 to 176%, respectively. The standard errors of simple and multiple regression estimators, which did not vary with the sampling interval, were 124 and 105%, respectively. Thus, the optimal off-line estimator (Kalman smoother) had the lowest error characteristics of those evaluated. Because suspended-sediment concentrations are typically measured at less than 3-day intervals, use of optimal estimators will likely result in significant improvements in the accuracy of continuous suspended-sediment concentration records. Additional research on the integration of direct suspended-sediment concentration measurements and optimal estimators applied at hourly or shorter intervals is needed. |
| Genre: | Article |
| ProdID: | 70024023 |
| Citation Author: | Holtschlag, D. J. |
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| Citation End Page: | 1155 |
| Citation Issue: | 7 |
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| Citation Language: | English |
| Citation Larger Work Title: | Hydrological Processes |
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| Citation Number Of Pages: | 23 |
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| Citation Search Results Text: | Optimal estimation of suspended-sediment concentrations in streams; 2001; Article; Journal; Hydrological Processes; Holtschlag, D. J. |
| Citation Start Page: | 1133 |
| Citation Volume: | 15 |
| Citation Year: | 2001 |
| Type: | citation/reference |
| Text: | Optimal estimation of suspended-sediment concentrations in streams; 2001; Article; Journal; Hydrological Processes; Holtschlag, D. J. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1002/hyp.207 |
| Date Other: | Mon, 1 Jan 2001 00:00 -0600 |
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