Header

UZH-Logo

Maintenance Infos

Incorporating landscape characteristics in a distance metric for interpolating between observations of stream water chemistry


Lyon, Steve W; Seibert, Jan; Lembo, A J; Steenhuis, T S; Walter, M T (2008). Incorporating landscape characteristics in a distance metric for interpolating between observations of stream water chemistry. Hydrology and Earth System Sciences, 12:1229-1239.

Abstract

Spatial patterns of water chemistry along stream networks can be quantified using synoptic or “snapshot” sampling. The basic idea is to sample stream water at many points over a relatively short period of time. Even for intense sampling campaigns, the number of sample points is limited and interpolation methods, like kriging, are commonly used to produce continuous maps of water chemistry based on the point observations from the synoptic sampling. Interpolated concentrations are influenced heavily by how distance between points along the stream network is defined. In this study, we investigate different ways to define distance and test these based on data from a snapshot sampling campaign in a 37-km2 watershed in the Catskill Mountains region (New York State). Three distance definitions (or metrics) were compared: Euclidean or straight-line distance, in-stream distance, and in-stream distance adjusted according characteristics of the local contributing area, i.e., an adjusted in-stream distance. Using the adjusted distance metric resulted in a lower cross-validation error of the interpolated concentrations, i.e., a better agreement of kriging results with measurements, than the other distance definitions. The adjusted distance metric can also be used in an exploratory manner to test which landscape characteristics are most influential for the spatial patterns of stream water chemistry and, thus, to target future investigations to gain process-based understanding of in-stream chemistry dynamics.

Abstract

Spatial patterns of water chemistry along stream networks can be quantified using synoptic or “snapshot” sampling. The basic idea is to sample stream water at many points over a relatively short period of time. Even for intense sampling campaigns, the number of sample points is limited and interpolation methods, like kriging, are commonly used to produce continuous maps of water chemistry based on the point observations from the synoptic sampling. Interpolated concentrations are influenced heavily by how distance between points along the stream network is defined. In this study, we investigate different ways to define distance and test these based on data from a snapshot sampling campaign in a 37-km2 watershed in the Catskill Mountains region (New York State). Three distance definitions (or metrics) were compared: Euclidean or straight-line distance, in-stream distance, and in-stream distance adjusted according characteristics of the local contributing area, i.e., an adjusted in-stream distance. Using the adjusted distance metric resulted in a lower cross-validation error of the interpolated concentrations, i.e., a better agreement of kriging results with measurements, than the other distance definitions. The adjusted distance metric can also be used in an exploratory manner to test which landscape characteristics are most influential for the spatial patterns of stream water chemistry and, thus, to target future investigations to gain process-based understanding of in-stream chemistry dynamics.

Statistics

Citations

4 citations in Web of Science®
5 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

39 downloads since deposited on 31 Jan 2013
20 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Institute of Geography
Dewey Decimal Classification:910 Geography & travel
Language:English
Date:2008
Deposited On:31 Jan 2013 17:16
Last Modified:07 Dec 2017 19:07
Publisher:Copernicus Publications
ISSN:1027-5606
Publisher DOI:https://doi.org/10.5194/hess-12-1229-2008

Download

Download PDF  'Incorporating landscape characteristics in a distance metric for interpolating between observations of stream water chemistry'.
Preview
Content: Published Version
Language: English
Filetype: PDF
Size: 405kB
View at publisher
Licence: Creative Commons: Attribution 3.0 Unported (CC BY 3.0)