Benchmarking a random forest for predicting preferential flow in soils

Preferential flow processes are important to fully understand flow and solute transport in the vadose zone and implement adequate management practices. Physical models are difficult to use at large scales to predict soil susceptibility to preferential flow. Instead, pedotransfer functions might b...

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Autor principal: Jordà Guerra, Helena
Formato: H2
Lenguaje:Inglés
Publicado: SLU/Dept. of Soil and Environment 2013
Materias:
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author Jordà Guerra, Helena
author_browse Jordà Guerra, Helena
author_facet Jordà Guerra, Helena
author_sort Jordà Guerra, Helena
collection Epsilon Archive for Student Projects
description Preferential flow processes are important to fully understand flow and solute transport in the vadose zone and implement adequate management practices. Physical models are difficult to use at large scales to predict soil susceptibility to preferential flow. Instead, pedotransfer functions might be applied. The strength of preferential flow can be measured by the relative 5% arrival time obtained from breakthrough curve (BTC) experiments. I used a database containing 560 BTC experiments to build random forests to predict the relative 5% arrival time and analyse the importance of soil properties and site factors on predicting this feature. The coefficient of determination for a 10-fold cross-validation was 70%, whereas the benchmarking process obtained a coefficient of 27%. Sand contents between 0.80 and 0.92 reached the highest importance and were strongly related to weak preferential flow. High importance was also observed in silt contents lower than 0.11, and clay contents between 0.04 and 0.08, which were strongly correlated to high preferential flow. In addition, experimental conditions such as flow rate, column diameter, the use of fixed drippers and column venting had 20% importance. This study revealed that texture can broadly predict soil susceptibility to preferential flow, while other site and soil factors can later refine this estimate. However, the dataset lacked land use information and a broader range of experimental conditions. I consider that enlarging the database is a key factor to obtain better predictions and to further understand how soil and site characteristics influence soil susceptibility to preferential flow.
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institution Swedish University of Agricultural Sciences
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spelling RepoSLU58172013-07-03T11:55:47Z Benchmarking a random forest for predicting preferential flow in soils Jordà Guerra, Helena preferential flow random forest benchmarking undisturbed soil soil database Preferential flow processes are important to fully understand flow and solute transport in the vadose zone and implement adequate management practices. Physical models are difficult to use at large scales to predict soil susceptibility to preferential flow. Instead, pedotransfer functions might be applied. The strength of preferential flow can be measured by the relative 5% arrival time obtained from breakthrough curve (BTC) experiments. I used a database containing 560 BTC experiments to build random forests to predict the relative 5% arrival time and analyse the importance of soil properties and site factors on predicting this feature. The coefficient of determination for a 10-fold cross-validation was 70%, whereas the benchmarking process obtained a coefficient of 27%. Sand contents between 0.80 and 0.92 reached the highest importance and were strongly related to weak preferential flow. High importance was also observed in silt contents lower than 0.11, and clay contents between 0.04 and 0.08, which were strongly correlated to high preferential flow. In addition, experimental conditions such as flow rate, column diameter, the use of fixed drippers and column venting had 20% importance. This study revealed that texture can broadly predict soil susceptibility to preferential flow, while other site and soil factors can later refine this estimate. However, the dataset lacked land use information and a broader range of experimental conditions. I consider that enlarging the database is a key factor to obtain better predictions and to further understand how soil and site characteristics influence soil susceptibility to preferential flow. SLU/Dept. of Soil and Environment 2013 H2 eng https://stud.epsilon.slu.se/5817/
spellingShingle preferential flow
random forest
benchmarking
undisturbed soil
soil database
Jordà Guerra, Helena
Benchmarking a random forest for predicting preferential flow in soils
title Benchmarking a random forest for predicting preferential flow in soils
title_full Benchmarking a random forest for predicting preferential flow in soils
title_fullStr Benchmarking a random forest for predicting preferential flow in soils
title_full_unstemmed Benchmarking a random forest for predicting preferential flow in soils
title_short Benchmarking a random forest for predicting preferential flow in soils
title_sort benchmarking a random forest for predicting preferential flow in soils
topic preferential flow
random forest
benchmarking
undisturbed soil
soil database