Publication Details

Category Text Publication
Reference Category Journals
DOI 10.5194/soil-6-215-2020
Licence creative commons licence
Title (Primary) Development of pedotransfer functions for water retention in tropical mountain soil landscapes: spotlight on parameter tuning in machine learning
Author Gebauer, A.; Ellinger, M.; Brito Gomez, V.M.; Ließ, M.
Source Titel Soil
Year 2020
Department BOSYS
Volume 6
Issue 1
Page From 215
Page To 229
Language englisch
Data and Software links https://doi.org/10.17605/OSF.IO/7UBWY
Abstract Machine-learning algorithms are good at computing non-linear problems and fitting complex composite functions, which makes them an adequate tool for addressing multiple environmental research questions. One important application is the development of pedotransfer functions (PTFs). This study aims to develop water retention PTFs for two remote tropical mountain regions with rather different soil landscapes: (1) those dominated by peat soils and soils under volcanic influence with high organic matter contents and (2) those dominated by tropical mineral soils. Two tuning procedures were compared to fit boosted regression tree models: (1) tuning with grid search, which is the standard approach in pedometrics; and (2) tuning with differential evolution optimization. A nested cross-validation approach was applied to generate robust models. The area-specific PTFs developed outperform other more general PTFs. Furthermore, the first PTF for typical soils of Páramo landscapes (Ecuador), i.e., organic soils under volcanic influence, is presented. Overall, the results confirmed the differential evolution algorithm's high potential for tuning machine-learning models. While models based on tuning with grid search roughly predicted the response variables' mean for both areas, models applying the differential evolution algorithm for parameter tuning explained up to 25 times more of the response variables' variance.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=23270
Gebauer, A., Ellinger, M., Brito Gomez, V.M., Ließ, M. (2020):
Development of pedotransfer functions for water retention in tropical mountain soil landscapes: spotlight on parameter tuning in machine learning
Soil 6 (1), 215 - 229 10.5194/soil-6-215-2020