A comparison of land surface model soil hydraulic properties estimated by inverse modeling and pedotransfer functions

Abstract. The objective of the present study is to test the performance of the ECMWF land surface module (LSM) developed by Viterbo and Beljaars (1995) and to identify primary future adjustments, focusing on the hydrological components. This was achieved by comparing off-line simulations against observations and a detailed state-of-the-art model over a range of experimental conditions. Results showed that the standard LSM, which uses fixed vegetation and soil parameter values, systematically underestimated evapotranspiration, partly due to underestimating bare soil evaporation, which appeared to be a conceptual problem. In dry summer conditions, transpiration was seriously underestimated. The bias in surface runoff and percolation was not of the same sign for all three locations. A sensitivity analysis, set up to explore the impact of using standard parameter values, found that implementing specific soil hydraulic properties had a significant effect on runoff and percolation at all three sites. Evapotranspiration, however affected only slightly at the temperate humid climate sites. Under semi-arid conditions, introducing site specific soil hydraulic properties plus a realistic rooting depth improved simulation results considerably. Future adjustments to the standard LSM should focus on parameter values of soil hydraulic functions and rooting depths and, conceptually, on the bare soil evaporation parameterisation and the soil bottom boundary condition. Implications of changing soil hydraulic properties for future large-simulations were explored briefly. For Europe, soil data requirements can be fulfilled partly by the recent data base HYPRES. Sandy and loamy sand soils will then cover about 65% of Europe, whereas in the present model 100% of the area is loam. Keywords: land surface model; soil hydraulic properties; water balance simulation

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Soil Hydraulic Properties Determined by Inverse Modeling of Drip Infiltrometer Experiments Extended with Pedotransfer Functions

Vadose Zone Journal ◽

10.2136/vzj2018.12.0215 ◽

2019 ◽

Vol 18 (1) ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

Ali Mehmandoost Kotlar ◽

Ioannis Varvaris ◽

Quirijn Jong van Lier ◽

Lis Wollesen de Jonge ◽

Per Møldrup ◽

...

Keyword(s):

Inverse Modeling ◽

Hydraulic Properties ◽

Pedotransfer Functions ◽

Soil Hydraulic Properties ◽

Soil Hydraulic

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Using observed soil moisture to constrain the uncertainty of simulated hydrological fluxes

10.22541/au.161734674.42560132/v1 ◽

2021 ◽

Author(s):

Andrew Ireson ◽

Seth Amankwah ◽

Sujan Basnet ◽

Talia Bobenic ◽

Morgan Braaten ◽

...

Keyword(s):

Soil Moisture ◽

Hydraulic Properties ◽

Pedotransfer Functions ◽

Surface Model ◽

Model Parameters ◽

Soil Hydraulic Properties ◽

Soil Moisture Storage ◽

Moisture Storage ◽

Hydrological Fluxes ◽

Soil Hydraulic

Using data from five long-term field sites measuring soil moisture, we show the limitations of using soil moisture observations alone to constrain modelled hydrological fluxes. We test a land surface model, MESH/CLASS, with two configurations: one where the soil hydraulic properties are determined using a pedotransfer function (the texture-based calibration) and one where they are assigned directly (the hydraulic properties-based calibration). The hydraulic properties-based calibration outperforms the texture-based calibration in terms of reproducing changes in soil moisture storage within a 1.6 m deep profile at each site, but both perform reasonably well, especially in the summer months. When the models are constrained using observations of changes in soil moisture, the predicted hydrological fluxes are subject to very large uncertainties associated with equifinality. The uncertainty is larger for the hydraulic properties-based calibration, even though the performance was better. We argue that since the pedotransfer functions constrain the model parameters in the texture-based calibrations in an unrealistic way, the texture-based calibration underestimates the uncertainty in the fluxes. We recommend that reproducing observed cumulative changes in soil moisture storage should be considered a necessary but insufficient criterion of model success. Additional sources of information are needed to reduce uncertainties, and these could include improved estimation of the soil hydraulic properties and direct observations of fluxes, particularly evapotranspiration.

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Evaluation and improvement of the default soil hydraulic parameters for the Noah Land Surface Model

Geoderma ◽

10.1016/j.geoderma.2016.09.022 ◽

2017 ◽

Vol 285 ◽

pp. 247-259 ◽

Cited By ~ 20

Author(s):

Andrea Sz. Kishné ◽

Yohannes Tadesse Yimam ◽

Cristine L.S. Morgan ◽

Bright C. Dornblaser

Keyword(s):

Land Surface ◽

Land Surface Model ◽

Surface Model ◽

Hydraulic Parameters ◽

Soil Hydraulic Parameters ◽

Noah Land Surface Model ◽

Soil Hydraulic

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Evaluation of pedotransfer functions for predicting soil hydraulic properties: A voyage from regional to field scales across Europe

Journal of Hydrology Regional Studies ◽

10.1016/j.ejrh.2021.100903 ◽

2021 ◽

Vol 37 ◽

pp. 100903

Author(s):

P. Nasta ◽

B. Szabó ◽

N. Romano

Keyword(s):

Hydraulic Properties ◽

Pedotransfer Functions ◽

Soil Hydraulic Properties ◽

Soil Hydraulic

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Geophysical mapping of soil texture variability in the root zone to improve modelling of the water and nutrient flow.

10.5194/egusphere-egu2020-19586 ◽

2020 ◽

Author(s):

Kim Schwartz Madsen ◽

Bo Vangsø Iversen ◽

Christen Duus Børgesen

Keyword(s):

Soil Texture ◽

Hydraulic Properties ◽

Root Zone ◽

Clay Fraction ◽

Clay Content ◽

Auxiliary Variable ◽

Pedotransfer Functions ◽

Soil Hydraulic Properties ◽

Sampling Density ◽

Soil Hydraulic

Modelling is often used to acquire information on water and nutrient fluxes within and out of the root zone. The models require detailed information on the spatial variability of soil hydraulic properties derived from soil texture and other soil characteristics using pedotransfer functions (PTFs). Soil texture can vary considerably within a field and is cumbersome and expensive to map in details using traditionally measurements in the laboratory. The electrical conductivity (EC) of the soil have shown to correlate with its textural composition.This study investigates the ability of electromagnetic induction (EMI) methods to predict clay content in three soil layers of the root zone. As the clay fraction often is a main predictor in PTFs predicting soil hydraulic properties this parameter is of high interest. EMI and soil textural surveys on four Danish agricultural fields with varying textural composition were used. Sampling density varied between 0.5 and 38 points per hectare. The EMI data was gathered with a Dualem21 instrument with a sampling density 200-3000 points per hectare. The EC values were used together with the measured values of the clay content creating a statistical relationship between the two variables. Co-kriging of the clay content from the textural sampling points with the EC as auxiliary variable produces clay content maps of the fields. Unused (80%) texture points were used for validation. EMI-predicted clay content maps and clay content maps based on the survey were compared. The two sets of soil texture maps are used as predictors for PTF models to predict soil hydraulic properties as input in field-scale root zone modelling.The comparisons between EC and clay content show some degree of correlation with an R2 in the range of 0.55 to 0.80 for the four fields. The field with the highest average clay content showed the best relationship between the two parameters. Co-kriging with EC decreased mean error by 0.016 to 0.52 and RMSE by 0.04 to 1.80 between observed and predicted clay maps.

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Pedotransfer in soil physics: trends and outlook — A review —

Agrokémia és Talajtan ◽

10.1556/0088.2015.64.2.3 ◽

2015 ◽

Vol 64 (2) ◽

pp. 339-360 ◽

Cited By ~ 11

Author(s):

Ya. Pachepsky ◽

K. Rajkai ◽

B. Tóth

Keyword(s):

Hydraulic Properties ◽

Overland Flow ◽

Extreme Event ◽

Temporal Stability ◽

Model Performance ◽

Pedotransfer Functions ◽

Soil Physics ◽

Labor Costs ◽

Soil Hydraulic Properties ◽

Soil Hydraulic

Parameters governing the retention and movement of water and chemicals in soils are notorious for the difficulties and high labor costs involved in measuring them. Often, there is a need to resort to estimating these parameters from other, more readily available data, using pedotransfer relationships. This work is a mini-review that focuses on trends in pedotransfer development across the World, and considers trends regarding data that are in demand, data we have, and methods to build pedotransfer relationships. Recent hot topics are addressed, including estimating the spatial variability of water contents and soil hydraulic properties, which is needed in sensitivity analysis, evaluation of the model performance, multimodel simulations, data assimilation from soil sensor networks and upscaling using Monte Carlo simulations. Ensembles of pedotransfer functions and temporal stability derived from “big data” as a source of soil parameter variability are also described. Estimating parameter correlation is advocated as the pathway to the improvement of synthetic datasets. Upscaling of pedotransfer relationships is demonstrated for saturated hydraulic conductivity. Pedotransfer at coarse scales requires a different type of input variables as compared with fine scales. Accuracy, reliability, and utility have to be estimated independently. Persistent knowledge gaps in pedotransfer development are outlined, which are related to regional soil degradation, seasonal changes in pedotransfer inputs and outputs, spatial correlations in soil hydraulic properties, and overland flow parameter estimation. Pedotransfer research is an integral part of addressing grand challenges of the twenty-first century, including carbon stock assessments and forecasts, climate change and related hydrological weather extreme event predictions, and deciphering and managing ecosystem services. Overall, pedotransfer functions currently serve as an essential instrument in the science-based toolbox for diagnostics, monitoring, predictions, and management of the changing Earth and soil as a life-supporting Earth system.

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Inverse estimation of soil hydraulic properties and water repellency following artificially induced drought stress

Journal of Hydrology and Hydromechanics ◽

10.2478/johh-2018-0002 ◽

2018 ◽

Vol 66 (2) ◽

pp. 170-180 ◽

Cited By ~ 7

Author(s):

Vilim Filipović ◽

Thomas Weninger ◽

Lana Filipović ◽

Andreas Schwen ◽

Keith L. Bristow ◽

...

Keyword(s):

Soil Water ◽

Inverse Modeling ◽

Hydraulic Properties ◽

Global Climate ◽

Water Repellency ◽

Irrigation Event ◽

Water Infiltration ◽

Soil Hydraulic Properties ◽

Soil Water Repellency ◽

Soil Hydraulic

AbstractGlobal climate change is projected to continue and result in prolonged and more intense droughts, which can increase soil water repellency (SWR). To be able to estimate the consequences of SWR on vadose zone hydrology, it is important to determine soil hydraulic properties (SHP). Sequential modeling using HYDRUS (2D/3D) was performed on an experimental field site with artificially imposed drought scenarios (moderately M and severely S stressed) and a control plot. First, inverse modeling was performed for SHP estimation based on water and ethanol infiltration experimental data, followed by model validation on one selected irrigation event. Finally, hillslope modeling was performed to assess water balance for 2014. Results suggest that prolonged dry periods can increase soil water repellency. Inverse modeling was successfully performed for infiltrating liquids, water and ethanol, withR2and model efficiency (E) values both > 0.9. SHP derived from the ethanol measurements showed large differences in van Genuchten-Mualem (VGM) parameters for the M and S plots compared to water infiltration experiments. SWR resulted in large saturated hydraulic conductivity (Ks) decrease on the M and S scenarios. After validation of SHP on water content measurements during a selected irrigation event, one year simulations (2014) showed that water repellency increases surface runoff in non-structured soils at hillslopes.

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