Assessment of pedotransfer functions for estimating soil water retention curves for the amazon region

Abstract

Knowledge of the soil water retention curve (SWRC) is essential for understanding and modeling hydraulic processes in the soil. However, direct determination of the SWRC is time consuming and costly. In addition, it requires a large number of samples, due to the high spatial and temporal variability of soil hydraulic properties. An alternative is the use of models, called pedotransfer functions (PTFs), which estimate the SWRC from easy-to-measure properties. The aim of this paper was to test the accuracy of 16 point or parametric PTFs reported in the literature on different soils from the south and southeast of the State of Pará, Brazil. The PTFs tested were proposed by Pidgeon (1972), Lal (1979), Aina & Periaswamy (1985), Arruda et al. (1987), Dijkerman (1988), Vereecken et al. (1989), Batjes (1996), van den Berg et al. (1997), Tomasella et al. (2000), Hodnett & Tomasella (2002), Oliveira et al. (2002), and Barros (2010). We used a database that includes soil texture (sand, silt, and clay), bulk density, soil organic carbon, soil pH, cation exchange capacity, and the SWRC. Most of the PTFs tested did not show good performance in estimating the SWRC. The parametric PTFs, however, performed better than the point PTFs in assessing the SWRC in the tested region. Among the parametric PTFs, those proposed by Tomasella et al. (2000) achieved the best accuracy in estimating the empirical parameters of the van Genuchten (1980) model, especially when tested in the top soil layer.

Pedotransfer Functions for Water Retention in the Main Soils From the Brazilian Coastal Plains

“…This fact can be explained by the great mineralogical uniformity in the soils (Duarte et al, 2000;Resende et al, 2011;Carvalho Filho;Fonseca, 2013) and in the parent material of soils from this environment (Nascimento et al, 2010). The lower R 2 values for YL can be related to this soil class being in much smaller number in the database, in agreement with its much smaller geographical expression in the Brazilian Coastal Plains (Carvalho Filho, Curi;Fonsêca, 2013).…”

“…The PTFs are commonly utilized in Soil Science, Hydrology and Agrometeorology for estimating water conductivity, water retention curve and parameters related to soil water infiltration (Medeiros et al, 2014). Many models utilize PTFs for simulating soil water, air and solutes transport, compaction, structure stability, and penetration resistance (Botula et al, 2014).…”

Evaluating pedotransfer functions of the Splintex model

“…A database of 50 datasets containing SWRC parameters, sand, silt and clay contents, ρ b , ρ p and ϕ was compiled from published data (Nunes, ; Pires et al , ; Matias et al , ; Uhde, ; Barros, ; Brito, ; Barreto & Medeiros, ; Lucas et al , ; Oliveira, ; Gimenes, ; Medeiros et al , ). In these studies, the SWRC data were measured with undisturbed samples on porous plates in pressure chambers and fitted to Equation (1) by non‐linear regression and minimizing the sum of squared errors.…”

“…() developed an important PTF from measured properties of several tropical soils from Brazil, whereas Medeiros et al . () evaluated point‐base and parametric PTFs for soil from Amazon region.…”

Avaliação Do Estado Trófico Do Rio Piracicaba E Sua Relação Com a Uhe – Sá Carvalho, Mg, Brasil

“…Dentre as alterações das características ecológicas (interações entre a biota e o ambiente aquático), destacam-se alteração nos parâmetros físico-químicos; elevação nos teores de metais pesados, incremento das concentrações dos nutrientes; perda de habitat; erosão; decaimento nos valores recreativos e estéticos do rio (Els et al, 2012). Além disso, os ecossistemas fluviais barrados e usados para geração de energia elétrica são afetados tanto a jusante, quanto a montante das barragens e com reflexos em toda a bacia de captação (Carvalho e Cuervo, 2013 produzir neurotoxinas e/ou hepatotoxinas que afetam a saúde humana e constituindo-se, portanto em grande obstáculo para as companhias de tratamento de água principalmente quando é observada ocorrência das condições ambientais propícias para a proliferação daqueles organismos aquáticos (Medeiros et al, 2014).…”