ISPRS Int. J. Geo-Inf. 2018, 7(2), 64; doi:10.3390/ijgi7020064
Accounting for and Predicting the Influence of Spatial Autocorrelation in Water Quality Modeling
1
Department of Geography, University of Kentucky, Lexington, KY 40508, USA
2
Department of Geography, Seoul National University, Seoul 08826, Korea
*
Author to whom correspondence should be addressed.
Received: 28 November 2017 / Revised: 7 February 2018 / Accepted: 17 February 2018 / Published: 19 February 2018
(This article belongs to the Special Issue Geographic Information Science and Spatial Analysis in Water Resources)
Abstract
Several studies in the hydrology field have reported differences in outcomes between models in which spatial autocorrelation (SAC) is accounted for and those in which SAC is not. However, the capacity to predict the magnitude of such differences is still ambiguous. In this study, we hypothesized that SAC, inherently possessed by a response variable, influences spatial modeling outcomes. We selected ten watersheds in the USA and analyzed if water quality variables with higher Moran’s I values undergo greater increases in the coefficient of determination (R2) and greater decreases in residual SAC (rSAC). We compared non-spatial ordinary least squares to two spatial regression approaches, namely, spatial lag and error models. The predictors were the principal components of topographic, land cover, and soil group variables. The results revealed that water quality variables with higher inherent SAC showed more substantial increases in R2 and decreases in rSAC after performing spatial regressions. In this study, we found a generally linear relationship between the spatial model outcomes (R2 and rSAC) and the degree of SAC in each water quality variable. We suggest that the inherent level of SAC in response variables can predict improvements in models before spatial regression is performed. View Full-TextKeywords:
spatial autocorrelation; water quality; spatial modeling; coefficient of determination; residual autocorrelation
▼
Figures
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
Share & Cite This Article
MDPI and ACS Style
Miralha, L.; Kim, D. Accounting for and Predicting the Influence of Spatial Autocorrelation in Water Quality Modeling. ISPRS Int. J. Geo-Inf. 2018, 7, 64.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
Related Articles
Article Metrics
Comments
[Return to top]
ISPRS Int. J. Geo-Inf.
EISSN 2220-9964
Published by MDPI AG, Basel, Switzerland
RSS
E-Mail Table of Contents Alert