Technical note: Saturated hydraulic conductivity and textural heterogeneity of soils

Abstract

Abstract. Saturated hydraulic conductivity (Ksat) is an important soil parameter that highly depends on soil's particle size distribution (PSD). The nature of this dependency is explored in this work in two ways, (1) by using the information entropy as a heterogeneity parameter of the PSD and (2) using descriptions of PSD in forms of textural triplets, different than the usual description in terms of the triplet of sand, silt, and clay contents. The power of this parameter, as a descriptor of ln⁡Ksat, was tested on a database larger than 19 000 soils. Bootstrap analysis yielded coefficients of determination of up to 0.977 for ln⁡Ksat using a triplet that combines very coarse, coarse, medium, and fine sand as coarse particles; very fine sand, and silt as intermediate particles; and clay as fine particles. The power of the correlation was analysed for different textural classes and different triplets using a bootstrap approach. Also, it is noteworthy that soils with finer textures had worse correlations, as their hydraulic properties are not solely dependent on soil PSD. This heterogeneity parameter can lead to new descriptions of soil PSD, other than the usual clay, silt, and sand, that can describe better different soil physical properties, that are texture-dependent.

Classification of Hydrological Relevant Parameters by Soil Hydraulic Behaviour

“…The Information Entropy for the triplet that subdivided the texture into the classes "very coarse sand", "coarse sand", and "all other" (cf. Figure 2 in [35]) shows a high similarity to the pattern of the soil classification based on hydraulic response found in the study at hand. Possibly, the distinction by heterogeneity with individual consideration of the coarsest sand-classes is a good indicator of soil hydraulic behaviour.…”

“…It is noteworthy, that our pattern resembles findings of [35], although their research approach was different. They analysed relationships between the saturated hydraulic conductivity and the particle size distribution, which was classified by means of various thresholds.…”

Global soil, landuse, evapotranspiration, historical and future weather databases for SWAT Applications

“…Level USDA* STRUCTx** From articles (SD)*** Clay35132–5540 (255)Clay-loam69135–15913 (46)Heavy-clay3362–5——Loam8122215–512558 (113)Loamy-sand70101130151–50856298 (133)Sand111117176151–508634330 (328)Sandy-clay1015262–5827 (83)Sandy-clay-loam1219445–152332 (170)Sandy-loam20477851–15212449 (183)Silt-loam7105415–512652 (96)Silty-clay3442–54—Silty-clay-loam3472–56180 (434)*https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/office/ssr10/tr/?cid=nrcs144p2_074846**https://structx.com/Soil_Properties_007.html***Based on García-Gutiérrez et al . 106 …”

Supplementary material to "Guidance on evaluating parametric model uncertainty at decision-relevant scales"

“…Zone Parameter Citations (Bristow & Campbell, 1984), (Hungerford et al, 1989), (Longman et al, 2012), (NREL, 2012), (Muleta & Nicklow, 2005), (Jennings et al, 2018), (Kaushal et al, 2011), (Campbell et al, 2019), (Lima et al, 2019;López et al, 2019;Zhang et al, 2019) Hillslope Parameter Citations (Winter et al, 1998) Soil Parameter Citations (Dingman, 1994, p. 222;García-Gutiérrez et al, 2018), (Dai et al, 2019), (Williams & Flanagan, 1996), (Froelich, 1975;Reybold & Matthews, 1976), (Clapp & Hornberger, 1978), (Molotch & Bales, 2006) Vegetation Parameter Citations (Leonard et al, 2017;Lin, 2019;Miles, 2015aMiles, , 2015b, (Hawkins et al, 2019), (White et al, 2000), (Berg & McClaugherty, 2003;Cross et al, 2005;Lin et al, 2015), (Jolly et al, 2005), (Ryan, 1991), (Landsberg & Waring, 1997), (Tjoelker et al, 2001), (Arora & Boer, 2003) This figure is provided to support the choice of using 5 years to spin-up the RHESSys model's water storage levels. RHESSys begins a simulation with the water table at the surface (0 saturation deficit).…”