Improving the field estimation of saturated hydraulic conductivity in soil survey

Soil Research ◽  
1997 ◽  
Vol 35 (4) ◽  
pp. 803 ◽  
Author(s):  
Neil McKenzie ◽  
David Jacquier
Keyword(s):  
Hydraulic Conductivity ◽  
Water Movement ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Land Evaluation ◽  
Levels Of Detail ◽  
Eastern Australia ◽  
Field Estimation ◽  
Morphological Variables ◽  
Soil Surveys

Prediction of the movement and storage of water in soil is central to quantitative land evaluation. However, spatial and temporal predictions have not been provided by most Australian soil surveys. The saturated hydraulic conductivity (Ks) is an essential parameter for description of water movement in soil and its estimation has been considered too difficult for logistic and technical reasons. The Ks cannot be measured everywhere and relationships with readily observed morphological variables have to be established. However, conventional morphology by itself is a poor predictor of Ks. We have developed a more functional set of morphological descriptors better suited to the prediction of Ks. The descriptors can be applied at several levels of detail. Measurements of functional morphology and Ks were made on 99 horizons from 36 sites across south-eastern Australia. Useful predictions of Ks were possible using field texture, grade of structure, areal porosity, bulk density, dispersion index, and horizon type. A simple visual estimate of areal porosity was satisfactory, although a more quantitative system of measurement provided only slightly better predictions. Regression trees gave more plausible predictive models than standard multiple regressions because they provided a realistic portrayal of the non-additive and conditional nature of the relationships between morphology and Ks. The results are encouraging and indicate that coarse-level prediction of Ks is possible in routine soil survey. Direct measurement of Ks does not appear to be generally feasible because of the high cost, dynamic nature of Ks, and substantial short-range variation in the field. Prediction is further constrained by the limited returns from more sophisticated morphological predictors. The degree to which this limits practical land evaluation is yet to be demonstrated.

ESTIMATING VERTICAL SATURATED HYDRAULIC CONDUCTIVITY FROM SOIL MORPHOLOGY IN ALBERTA

1989 ◽  
Vol 69 (1) ◽  
pp. 1-16 ◽  
Author(s):  
G. M. COEN ◽  
C. Wang
Keyword(s):  
Hydraulic Conductivity ◽  
Measurement Techniques ◽  
Field Measurements ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Soil Morphology ◽  
Soil Series ◽  
Management Procedures ◽  
The Mean

Vertical saturated hydraulic conductivity, as an important soil characteristic, should be part of the information displayed on soil survey maps. As rigorous measurement techniques are relatively slow and cumbersome, a rapid procedure for estimating vertical saturated hydraulic conductivity of soils using soil morphology was tested for Prairie conditions. Morphological estimates of vertical saturated hydraulic conductivity were compared to field measurements using an air entry permeameter for 36 sites representing 25 soil series. Eighty-three percent of the estimated values were within one saturated hydraulic conductivity class of the mean measured value. It was concluded that morphological observations are sufficiently accurate to allow field characterization of pedons. In Alberta, in Chernozemic areas, management procedures do not appear to modify strongly the saturated hydraulic conductivity. This in turn allows useful predictions of saturated hydraulic conductivity to be related to soil series concepts and therefore allows extrapolation to manageable tracts of land using map unit concepts. Key words: Saturated hydraulic conductivity, soil morphology, Alberta, estimating

Prediction of three key hydraulic properties in a soil survey of a small forested catchment

Soil Research ◽  
2002 ◽  
Vol 40 (2) ◽  
pp. 191 ◽  
Author(s):  
D. A. O'Connell ◽  
P. J. Ryan
Keyword(s):  
Hydraulic Conductivity ◽  
Water Content ◽  
Bulk Density ◽  
Hydraulic Properties ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Coarse Grained ◽  
Pedotransfer Functions ◽  
Explanatory Variables ◽  
Tree Models

Direct measurement of ψ(θ) and K(θ) relationships at all observation sites in soil survey is not feasible. Three key hydraulic properties — water content at field capacity (θ–5 kPa), water content at wilting point (θ–1.5 MPa), and saturated hydraulic conductivity (Ks) — can be used to derive K(θ) and ψ(θ) when combined with bulk density. These properties were measured in 'calibration' horizons in a soil survey in Yambulla State Forest in south-east New South Wales. Pedotransfer functions (PTFs) for predicting θ-5 kPa, θ–1.5 MPa, and Ks from the physical and morphologic soil attributes are presented and evaluated here. Models for predicting θ–5 kPa and θ–1.5 MPa relied on per cent clay. An R2 of 0.64 (for θ–5 kPa) to 0.67 (for θ–1.5 MPa) was obtained for linear regressions using only morphologic explanatory variables. An R2 of 0.73 (for θ–5 kPa) to 0.90 (for θ–1.5 MPa) was obtained if laboratory-measured clay content was included as an explanatory variable. Ks was measured in situ using well permeameters, and used for developing PTFs. Large cores were taken from a small subsample of horizons and measurements of Ks, K–0.1 kPa, K–0.2 kPa, and K–0.5 kPa were made in the laboratory. Ks measurements from well permeameters were similar to K-0.5 kPa from laboratory measurements. Regression and tree models were used to predict Ks. The linear regression had an R2 of 0.55, while the tree models accounted for approximately 40% reduction in deviance. Bulk density was the most useful predictor in all Ks models. The inclusion of per cent rock fragments, bulk density, and estimated percentage clay as useful explanatory variables demonstrated the utility of functional descriptors not routinely measured in soil survey. The models are empirical and were locally calibrated for use in a soil survey. They may be applicable in target domains similar to the source domain (i.e. coarse-grained adamellite soils in similar climatic regimes). surrogates, saturated hydraulic conductivity, K(θ), ψ(θ), Ks, pedotransfer functions, soil survey, soil morphology, PTF.

scholarly journals Performance Evaluation of MLP and RBF Neural Networks to Estimate the Soil Saturated Hydraulic Conductivity

2016 ◽  
Vol 11 (3) ◽  
pp. 1
Author(s):  
Elmira Sadat Shams Emamzadeh ◽  
Jaber Soltani ◽  
Mahmuod Mashal ◽  
Moosa Kalanaki ◽  
Tohid Asadolahzadeh
Keyword(s):  
Neural Networks ◽  
Hydraulic Conductivity ◽  
Mean Squared Error ◽  
Water Movement ◽  
Saturated Hydraulic Conductivity ◽  
Rbf Neural Networks ◽  
Squared Error ◽  
Flow Through ◽  
Mlp Neural Networks ◽  
Cased Borehole

Soil saturated hydraulic conductivity is considered one of the physical soil properties that is very important in modeling of water movement and environmental studies. This study aimed to compare the performance of Multi-Layer Perceptron (MLP) and Radial Basis Function (RBF) in neural networks for estimation of the soil saturated hydraulic conductivity. For this, the data of 27 drilled cased borehole permeameter with three kinds of geometry water flow through the soils and the soil texture properties were used as the input parameters for models. The effectiveness of neural networks to estimate the soil saturated hydraulic conductivity were calculated and compared based on mean squared error (MSE), root mean squared error (RMSE) and coefficient determination (R2). According to the above indicators, for all three types of drilled cased borehole permeameter surveyed in this study, the results show MLP neural networks had better performance than RBF neural networks in estimation of the soil saturated hydraulic conductivity and for wells with the horizontal, vertical and horizontal-vertical flow, which the amount of coefficient determination were respectively for all of them 0.94, 0.97 and 0.85.

Simulating Soil-Water Movement through Loess-Veneered Landscapes Using Nonconsilient Saturated Hydraulic Conductivity Measurements

2014 ◽  
Vol 78 (4) ◽  
pp. 1320-1331 ◽  
Author(s):  
T. N. Williamson ◽  
B. D. Lee ◽  
P. J. Schoeneberger ◽  
W. M. McCauley ◽  
S. J. Indorante ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Water ◽  
Water Movement ◽  
Saturated Hydraulic Conductivity ◽  
Conductivity Measurements ◽  
Soil Water Movement

scholarly journals GIS IN SOIL SURVEY AND SOIL MAPPING

2021 ◽  
Vol 47 (2) ◽  
pp. 80-88
Author(s):  
Perparim Ameti ◽  
Besim Ajvazi
Keyword(s):  
Land Use Planning ◽  
Planning Process ◽  
Data Communication ◽  
Soil Classification ◽  
Communication Technologies ◽  
Soil Survey ◽  
Land Evaluation ◽  
Reference Base ◽  
World Reference Base ◽  
Soil Surveys

The main goal of this paper is to present a methodology for land evaluation by supporting decision-makers with reliable information for the land-use planning process. One of the focuses of this paper is given to the survey process and interpretation between soil survey, soil survey interpretation, and physical land evaluation. Such processes are realized using mobile mapping tools with integrated Global Position Systems (GPS) and Geographic Information Systems (GIS). Both have increased the efficiency of data communication technologies by enabling real-time communication between people located in the field and office as well. For the soil classification as a key component of soil surveys is used World Reference Base (WRB) for Soil Resources. This is a common tool to summarize the wealth of information from soil profiles for the purpose of land evaluation. The final results showed a soil classification map. Such results are derived from many activities, since it includes a preliminary land evaluation, field soil survey with auger holes and profiles as well. This methodology is used for the first time in the selected study area.

Obtaining soil hydraulic properties for water balance and leaching models from survey data. 2. Hydraulic conductivity

1999 ◽  
Vol 50 (7) ◽  
pp. 1259 ◽  
Author(s):  
K. R. J. Smettem ◽  
K. L. Bristow
Keyword(s):  
Hydraulic Conductivity ◽  
Water Balance ◽  
Survey Data ◽  
Hydraulic Properties ◽  
Regional Scale ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Attractive Alternative ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic

Regional scale application of water and solute transport models is often limited by the lack of available data describing soil hydraulic properties and their variability. Direct measurement over large areas is expensive and time consuming. Physico-empirical models derived from soil survey data are therefore an attractive alternative. If the Marshall method of estimating the saturated hydraulic conductivity is simplified to depend primarily on the maximum pore radius, given by the bubbling pressure, then it is equivalent to the Campbell model of saturated hydraulic conductivity which relies entirely on an estimate of the bubbling pressure obtained from particle size data. We apply this simplified physico-empirical model to estimate the ‘matrix’, or textural saturated hydraulic conductivity, K m, using estimates of the bubbling pressure derived entirely from clay content data that are readily available in soil surveys. Model estimates are compared with in situ measurements on surface soils obtained using a disc permeameter with a negative pressure head at the supply surface of 40 mm. Results appear to be satisfactory for broad-scale water balance and leaching risk models that require specification of a matching point for the unsaturated hydraulic conductivity function and for modelling applications requiring generalised application of results from experimental sites.

Field-saturated hydraulic conductivity estimated using class numbers of soil survey

CATENA ◽  
2021 ◽  
Vol 204 ◽  
pp. 105431
Author(s):  
Edzard Hangen ◽  
Friedhelm Vieten ◽  
Uwe Geuß
Keyword(s):  
Hydraulic Conductivity ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Class Numbers

Evaluation of methods for inferring air and water properties of soils from field morphology

Soil Research ◽  
1991 ◽  
Vol 29 (5) ◽  
pp. 587 ◽  
Author(s):  
NJ Mckenzie ◽  
KRJ Smettem ◽  
AJ Ringrose-Voase
Keyword(s):  
Hydraulic Conductivity ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Soil Morphology ◽  
Water Properties ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity ◽  
Using Data ◽  
Semi Empirical

The accurate characterization of soil water and air properties is difficult in soil survey because of logistic constraints. Less reliable surrogates are commonly used to estimate these properties. The surrogates provide a method for moving from measures that tend to be static and semi-empirical to those characterizing soil processes. The utility of four schemes for predicting air-filled porosity, available water capacity and saturated hydraulic conductivity on the basis of field-determined soil morphology has been assessed using data from a limited number of profiles with features commonly encountered in Australia. None of the systems provided statistically significant predictions of available water capacity and the results for air-filled porosity were moderate (McKeague et al. (1986), r2 = 0.58; Hall et al. (19771, r2 = 0 -64; Williams et al. (1991), r2 = 0.70). Encouragingly, the Hollis and Woods (1989) system generated good predictions of field-saturated hydraulic conductivity (r2 = 0.77). It is concluded that better measurement methods and programs of data collection are needed for both the properties used as surrogates (e.g. morphology) and those for which predictions are required (e.g. air and water properties).

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

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 94
Author(s):  
Fernando E. Juliá ◽  
Victor A. Snyder ◽  
Miguel A. Vázquez
Keyword(s):  
Puerto Rico ◽  
Hydraulic Conductivity ◽  
Lower Class ◽  
Saturated Hydraulic Conductivity ◽  
Point Of View ◽  
Soil Survey ◽  
Geometric Standard Deviation ◽  
Soil Series ◽  
Order Of Magnitude ◽  
Survey Estimates

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

Sign in / Sign up

Export Citation Format

Share Document