| Abstract: | This paper addresses two components of the problem of estimating the magnitude of step trends in surface water quality. The first is finding a robust estimator appropriate to the data characteristics expected in water-quality time series. The J. L. Hodges-E. L. Lehmann class of estimators is found to be robust in comparison to other nonparametric and moment-based estimators. A seasonal Hodges-Lehmann estimator is developed and shown to have desirable properties. Second, the effectiveness of various sampling strategies is examined using Monte Carlo simulation coupled with application of this estimator. The simulation is based on a large set of total phosphorus data from the Potomac River. To assure that the simulated records have realistic properties, the data are modeled in a multiplicative fashion incorporating flow, hysteresis, seasonal, and noise components. The results demonstrate the importance of balancing the length of the two sampling periods and balancing the number of data values between the two periods. |
| Genre: | Article |
| ProdID: | 70013756 |
| Citation Author: | Hirsch, Robert, M. |
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| Citation End Page: | 503 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Water Resources Bulletin |
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| Citation Number Of Pages: | 11 |
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| Citation Publisher: | American Water Resources Association |
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| Citation Search Results Text: | Statistical Methods and Sampling Design for Estimating Step Trends in Surface-Water Quality; 1988; Article; Journal; Water Resources Bulletin; Hirsch, Robert, M. |
| Citation Start Page: | 493 |
| Citation Volume: | 24 |
| Citation Year: | 1988 |
| Type: | citation/reference |
| Text: | Statistical Methods and Sampling Design for Estimating Step Trends in Surface-Water Quality; 1988; Article; Journal; Water Resources Bulletin; Hirsch, Robert, M. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1111/j.1752-1688.1988.tb00899.x |
| Date Other: | Fri, 1 Jan 1988 00:00 -0600 |
| Publisher: | American Water Resources Association |
