liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Semiparametric approaches to flow normalization and source apportionment of substance transport in rivers
Stålnacke, P., Jordforsk - Ctr. Soil Environ. Res., NO-1432 Aas, Norway.
Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Mathematics, Statistics .
2001 (English)In: Environmetrics, ISSN 1180-4009, Vol. 12, no 3, 233-250 p.Article in journal (Refereed) Published
Abstract [en]

Statistical analysis of relationships between time series of data exhibiting seasonal variation is often of great interest in environmental monitoring and assessment. The present study focused on regression models with time-varying intercept and slope parameters. In particular, we derived and tested semiparametric models in which rapid interannual and interseasonal variation in the intercept were penalized in the search for a model that combined a good fit to data with smoothly varying parameters. Furthermore, we developed a software package for efficient estimation of the parameters of such models. Test runs on time series of runoff data and riverine loads of nutrients and chloride in the Rhine River showed that the proposed smoothing methods were particularly useful for analysis of time-varying linear relationships between time series of data with both seasonal variation and temporal trends. The predictivity of the semiparametric models was superior to that of conventional parametric models. In addition, normalization of observed annual loads to mean or minimum runoff produced smooth curves that provided convincing evidence of human impact on water quality. © 2001 John Wiley & Sons, Ltd.

Place, publisher, year, edition, pages
2001. Vol. 12, no 3, 233-250 p.
Keyword [en]
Regression, Rhine River, Riverine load, Roughness penalty, Runoff, Semiparametric, Smoothing
National Category
Social Sciences
URN: urn:nbn:se:liu:diva-47394DOI: 10.1002/env.459OAI: diva2:268290
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2011-01-13

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Grimvall, Anders
By organisation
Faculty of Arts and SciencesStatistics
In the same journal
Social Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 31 hits
ReferencesLink to record
Permanent link

Direct link