Mapping impact of intense rainfall on a high-severity burned area using principal component analysis

High-severity wildfires have a major impact on soil properties. Moreover, recently burned areas are highly sensitive to intense rainfall events. However, little is known about the impact of extreme rainfall on the relationship between soil properties and their spatial distribution. The objective of...

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Main Authors: M. Francos, P. Pereira, X. Úbeda
Format: Article
Language:English
Published: Universidad de La Rioja 2019-09-01
Series:Cuadernos de Investigación Geográfica
Subjects:
Online Access:https://publicaciones.unirioja.es/ojs/index.php/cig/article/view/3516
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author M. Francos
P. Pereira
X. Úbeda
author_facet M. Francos
P. Pereira
X. Úbeda
author_sort M. Francos
collection DOAJ
description High-severity wildfires have a major impact on soil properties. Moreover, recently burned areas are highly sensitive to intense rainfall events. However, little is known about the impact of extreme rainfall on the relationship between soil properties and their spatial distribution. The objective of this study is to examine the effects of an intense rainfall event on soil properties and their spatial distribution in a small area using principal component analysis (PCA). The variables studied were aggregate stability (AS), total nitrogen (TN), soil organic matter (SOM), inorganic carbon (IC), C/N ratio, calcium carbonates (CaCO3), pH, electrical conductivity (EC), available phosphorus (P), extractable calcium (Ca), extractable magnesium (Mg), extractable sodium (Na) and extractable potassium (K). Each PCA (before and after intense rainfall event) allowed us to extract five factors. Factor 1 in the pre-intense rainfall event PCA explained the variance of EC, available P, extractable Mg and K; factor 2 accounted for TN, SOM (high loadings), IC and CaCO3 (low loadings); factor 3 explained AS, extractable Ca and Na; and, factors 4 and 5 accounted for C/N and pH, respectively. Factor 1 in the after intense rainfall event PCA explained the variance of TN, SOM, EC, available P, extractable Mg and K (high loadings) and pH (low loading); factor 2 accounted for IC and CaCO3; factor 3 explained extractable Ca and Na; factor 4 accounted for AS; and, factor 5 for C/N. The results showed that the intense rainfall event changed the relationship between the variables, strengthening the correlation between them, especially in the case of TN, SOM, EC, available P, extractable Mg and extractable Ca with AS. In the case of the pre-intense rainfall event PCA, the best- fit variogram models were: factors 1 and 2 – the linear model; factors 3 and 4 – the pure nugget effect; and, factor 5 – the spherical model. In the case of the factors after intense rainfall event PCA, with the exception of factor 5 (spherical model), the best fit model was the linear model. The PCA score maps illustrated a marked change in the spatial distribution of the variables before and after the intense rainfall event. Important differences were detected in AS, pH, C/N IC, CaCO3, extractable Ca and Na.
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spelling doaj.art-4a1399c5396b47eebcb132bdfec7c2cd2022-12-22T00:00:58ZengUniversidad de La RiojaCuadernos de Investigación Geográfica0211-68201697-95402019-09-0145260162110.18172/cig.35163133Mapping impact of intense rainfall on a high-severity burned area using principal component analysisM. Francos0P. Pereira1X. Úbeda2University of BarcelonaMykolas Romeris UniversityUniversity of BarcelonaHigh-severity wildfires have a major impact on soil properties. Moreover, recently burned areas are highly sensitive to intense rainfall events. However, little is known about the impact of extreme rainfall on the relationship between soil properties and their spatial distribution. The objective of this study is to examine the effects of an intense rainfall event on soil properties and their spatial distribution in a small area using principal component analysis (PCA). The variables studied were aggregate stability (AS), total nitrogen (TN), soil organic matter (SOM), inorganic carbon (IC), C/N ratio, calcium carbonates (CaCO3), pH, electrical conductivity (EC), available phosphorus (P), extractable calcium (Ca), extractable magnesium (Mg), extractable sodium (Na) and extractable potassium (K). Each PCA (before and after intense rainfall event) allowed us to extract five factors. Factor 1 in the pre-intense rainfall event PCA explained the variance of EC, available P, extractable Mg and K; factor 2 accounted for TN, SOM (high loadings), IC and CaCO3 (low loadings); factor 3 explained AS, extractable Ca and Na; and, factors 4 and 5 accounted for C/N and pH, respectively. Factor 1 in the after intense rainfall event PCA explained the variance of TN, SOM, EC, available P, extractable Mg and K (high loadings) and pH (low loading); factor 2 accounted for IC and CaCO3; factor 3 explained extractable Ca and Na; factor 4 accounted for AS; and, factor 5 for C/N. The results showed that the intense rainfall event changed the relationship between the variables, strengthening the correlation between them, especially in the case of TN, SOM, EC, available P, extractable Mg and extractable Ca with AS. In the case of the pre-intense rainfall event PCA, the best- fit variogram models were: factors 1 and 2 – the linear model; factors 3 and 4 – the pure nugget effect; and, factor 5 – the spherical model. In the case of the factors after intense rainfall event PCA, with the exception of factor 5 (spherical model), the best fit model was the linear model. The PCA score maps illustrated a marked change in the spatial distribution of the variables before and after the intense rainfall event. Important differences were detected in AS, pH, C/N IC, CaCO3, extractable Ca and Na.https://publicaciones.unirioja.es/ojs/index.php/cig/article/view/3516wildfirespatial modelingprincipal component analysissoil chemical propertiesintense rainfall
spellingShingle M. Francos
P. Pereira
X. Úbeda
Mapping impact of intense rainfall on a high-severity burned area using principal component analysis
Cuadernos de Investigación Geográfica
wildfire
spatial modeling
principal component analysis
soil chemical properties
intense rainfall
title Mapping impact of intense rainfall on a high-severity burned area using principal component analysis
title_full Mapping impact of intense rainfall on a high-severity burned area using principal component analysis
title_fullStr Mapping impact of intense rainfall on a high-severity burned area using principal component analysis
title_full_unstemmed Mapping impact of intense rainfall on a high-severity burned area using principal component analysis
title_short Mapping impact of intense rainfall on a high-severity burned area using principal component analysis
title_sort mapping impact of intense rainfall on a high severity burned area using principal component analysis
topic wildfire
spatial modeling
principal component analysis
soil chemical properties
intense rainfall
url https://publicaciones.unirioja.es/ojs/index.php/cig/article/view/3516
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AT ppereira mappingimpactofintenserainfallonahighseverityburnedareausingprincipalcomponentanalysis
AT xubeda mappingimpactofintenserainfallonahighseverityburnedareausingprincipalcomponentanalysis