Resumo

GOMEZ-TAGLE CH., Alberto et al. Field Saturated Hydraulic Conductivity: Use of a Portable Constant-Head and Single-Ring Infiltrometer. Terra Latinoam [online]. 2008, vol.26, n.4, pp.287-297. ISSN 2395-8030.

Infiltration is the process that occurs when water penetrates the soil surface. During an infiltration experiment, infiltration rate diminishes with time until reaching a constant value controlled mainly by field saturated hydraulic conductivity (K_sf). This highly variable hydraulic soil property requires an important sample size to be properly characterized. Therefore, equipment availability is crucial in order to acquire representative data in a reasonable time. The objectives in this work were a) to build an inexpensive, low weight and low water consumption infiltrometer, b) to compare the performance of three different methods to estimate K_sf from data acquired with the constructed infiltrometer, and c) to compare the estimated K_sf values with those obtained by means of a Guelph permeameter. The research was conducted in the Mexican volcanic belt within the soil formations Huiramba sand, Jorullo sand, Umecuaro silt, Cointzio loam, and Atecuaro clay. K_sf was obtained using the methods Wu1 and Wu2 for a first and second pressure head and the two charges for the single ring method (TCSR). Mean K_sf varied between 0.0785 and 9889.65 mm h^-1 depending on texture and method used. The TCSR method generated both the highest mean values of this work (21 827 mm h^-1) and the most unrealistic negative values, revealing that it is significantly different from the other methods since it required more water and time. For the Wu1 method mean K_sf varied from 5.50 to 848.19 mm h^-1 and for the Wu2 method from 3.18 to 3975.24 mm h^-1 with the first charge head, and from 94.12 to 4505.99 mm h^-1 with the second charge. The most robust method was Wu2 that fit in all infiltration tests and did not require estimation of Δθ, as did Wu1, and it was statistically equal to the reference device.

Palavras-chave : infiltration; Mexican volcanic belt; hydrological ecosystem services; Cuitzeo watershed.

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