Using landscape characteristics to define an adjusted distance metric for improving kriging interpolations
2010 (English)In: International Journal of Geographical Information Science, ISSN 1365-8816, E-ISSN 1362-3087, Vol. 24, no 5, 723-740 p.Article in journal (Refereed) Published
Interpolation of point measurements using geostatistical techniques such as kriging can be used to estimate values at non-sampled locations in space. Traditional geostatistics are based on the spatial autocorrelation concept that nearby things are more related than distant things. In this study, additional information was used to modify the traditional Euclidean concept of distance into an adjusted distance metric that incorporates similarity in terms of quantifiable landscape characteristics such as topography or land use. This new approach was tested by interpolating soil moisture content, pH and carbon-tonitrogen (C:N) ratio measured in both the mineral and the organic soil layers at a field site in central Sweden. Semivariograms were created using both the traditional distance metrics and the proposed adjusted distance metrics to carry out ordinary kriging (OK) interpolations between sampling points. In addition, kriging with external drift (KED) was used to interpolate soil properties to evaluate the ability of the adjusted distance metric to incorporate secondary data into interpolations. The new adjusted distance metric typically lowered the nugget associated with the semivariogram, thereby better representing small-scale variability in the measured data compared to semivariograms based on the traditional distance metric. The pattern of the resulting kriging interpolations using KED and OK based on the adjusted distance metric were similar because they represented secondary data and, thus, enhanced small-scale variability compared to traditional distance OK. This created interpolations that agreed better with what is expected for the real-world spatial variation of the measured properties. Based on cross-validation error, OK interpolations using the adjusted distance metric better fit observed data than either OK interpolations using traditional distance or KED. Â© 2010 Taylor & Francis.
Place, publisher, year, edition, pages
2010. Vol. 24, no 5, 723-740 p.
C:N ratio, Geostatistics, Kriging, Semivariogram, Soil moisture, Soil pH
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-143470DOI: 10.1080/13658810903062487OAI: oai:DiVA.org:uu-143470DiVA: diva2:390106