Validation of Soil Survey Estimates of Saturated Hydraulic Conductivity in Major Soils of Puerto Rico

Ranges or “classes” of probable saturated hydraulic conductivity values (Ksat) are listed for all soil series in USDA-NRCS Soil Survey reports. Listed not measured, but rather estimated from other properties using a pedotransfer function (PTF). To validate the PTF, we compared Ksat classes with measured various horizons nine major Puerto Rico. For each horizon, minimum 9 and usually 16 measurements were made Guelph permeameters near locations where pedons had been thoroughly described. In most horizons, was log-normally distributed. The ratios corresponding to one geometric standard deviation above below mean less than 10, which is ratio upper lower class boundaries classification system. distributed among rated next higher class, indicating that PTF systematically underestimated distributions, by an order magnitude. From point view water management decisions requiring conservative estimates, estimates appeared reasonably without deviating actual so as limit usefulness estimates.