Publicação
Evaluation of pedotransfer functions for predicting soil water retention in portuguese soils
| Resumo: | Estimates of soil water retention characteristics using pedotransfer functions (PTFs) are useful in many studies, such as hydrological modelling and soil mapping. The determination of the parameters for these functions can be obtained from direct laboratory and field measurements. However, these measurements are time consuming which makes it costly to characterise an extensive area of a land. As an alternative, the existing databases of measured soil hydraulic data may be used to obtained hydraulic parameters by fitting the water retention functions or to develop PTFs from easily measured properties, such as texture, bulk density and soil organic matter content. The objective of this study was to evaluate four published PTFs (Rawls – Brakensiek, Vereecken, Mayr – Jarvis e Campbell) to estimate the parameters of soil water retention functions for Portuguese soils. Two different soil data sets from North of Portugal (231 horizons), consisting of a full description of soil properties and soil water retention characteristics, were used in this study. Soil water retention function parameters were estimated for Campbell, Brooks – Corey, van Genuchten and Hutson – Cass functions by fitting to soil water content‐pressure data, using an algorithm based on the simplex method and by application of a PTF for each function. The PTFs were evaluated by comparison of predicted and measured water contents at field capacity and permanent wilting point. The results showed a good performance of Brooks – Corey function with parameters predicted by Rawls – Brakensiek PTF. |
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| Autores principais: | Ribeiro, A.C. |
| Ano: | 2010 |
| País: | Portugal |
| Tipo de documento: | documento de conferência |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | português |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | Estimates of soil water retention characteristics using pedotransfer functions (PTFs) are useful in many studies, such as hydrological modelling and soil mapping. The determination of the parameters for these functions can be obtained from direct laboratory and field measurements. However, these measurements are time consuming which makes it costly to characterise an extensive area of a land. As an alternative, the existing databases of measured soil hydraulic data may be used to obtained hydraulic parameters by fitting the water retention functions or to develop PTFs from easily measured properties, such as texture, bulk density and soil organic matter content. The objective of this study was to evaluate four published PTFs (Rawls – Brakensiek, Vereecken, Mayr – Jarvis e Campbell) to estimate the parameters of soil water retention functions for Portuguese soils. Two different soil data sets from North of Portugal (231 horizons), consisting of a full description of soil properties and soil water retention characteristics, were used in this study. Soil water retention function parameters were estimated for Campbell, Brooks – Corey, van Genuchten and Hutson – Cass functions by fitting to soil water content‐pressure data, using an algorithm based on the simplex method and by application of a PTF for each function. The PTFs were evaluated by comparison of predicted and measured water contents at field capacity and permanent wilting point. The results showed a good performance of Brooks – Corey function with parameters predicted by Rawls – Brakensiek PTF. |
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