Modelling soil water dynamics in the unsaturated zone — State of the art

Feddes, R.A.; Kabat, P.; Bakel, P.J.T. van; Bronswijk, J.J.B.; Halbertsma, J.

doi:10.1016/0022-1694(88)90182-5

Cited by 263 publications

(115 citation statements)

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“…To take into account tree physiology and the reduction of transpiration by soil water stress for a typical oak tree, the water uptake term is distributed over the whole root zone and is calculated for each cell (Feddes et al, 1988) …”

Section: Sink Termmentioning

confidence: 99%

“…Evaporation from short grass and trees is computed by multiplying E p by a parameter β (Feddes et al, 1988). The β parameter is smaller than one and takes account of the different biophysical properties of the vegetation, which leads to a reduction in the evaporation rate E p , even when there is no water stress.…”

Section: Transpiration Fractionmentioning

confidence: 99%

“…For the upper boundary condition, the original model solves a two source (vegetation and bare soil) energy balance system, whereas the version used in this paper is based on the prescription of a potential evaporation for bare soil and a potential transpiration for vegetation. For each soil layer, root water uptake is the product of several terms: potential transpiration, root density and a water stress correcting factor (Feddes et al, 1988). In this study, the root density function and the water stress factor are customised for trees.…”

Section: Appendix: the Boundary Conditionsmentioning

confidence: 99%

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A Linking Test that establishes if groundwater recharge can be determined by optimising vegetation parameters against soil moisture

Pollacco

Braud²,

Angulo-Jaramillo

et al. 2008

Ann. For. Sci.

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Abstract• The impact of afforestation/deforestation on groundwater recharge can be predicted by using onedimensional soil-vegetation water flow models based on Richards' equation. However simulations depend upon parameters that are not easily measurable.• Pollacco et al. (2008) showed that the hydraulic parameters can be determined, if the vegetation parameters are known, by fitting simulated time series of soil moisture profiles to those measured in situ. This paper presents a case study to determine if the interception and crop factor parameters can tentatively be calibrated by fitting soil moisture profiles. Synthetic data were used and the other vegetation parameters and the soil hydraulic parameters were assumed to be known.• We applied and improved the Linking Test developed by Pollacco et al. (2008) to look for links between the parameters that need to be calibrated, and thus to investigate whether inverse modelling is feasible, which depends on the accuracy of the calibration data.• The Linking Test established that interception and evapotranspiration parameters are linked and, therefore, uncertainty on interception compensates for uncertainty on evapotranspiration. Thus in spite of a good match between observed and simulated soil moisture data, inverse modelling is unfeasible. This is true even if the interception or the crop factor parameters are known, because an error on interception or evapotranspiration will be compensated by an error on groundwater recharge without affecting soil moisture.• This paper recommends that vegetation parameters should not be calibrated by optimisation against soil moisture data. • L'impact de la déforestation/reforestation, sur la recharge des eaux souterraines, peut être quantifié en employant les modèles unidimensionnels d'écoulement dans le continuum sol-plante-atmosphère. Ces modèles sont fondés sur la solution de l'équation de Richards. Cependant, quel que soit le modèle, les simulations dépendent de paramètres qui sont difficilement mesurables. • Le Test de Liaison a permis d'établir le degré de liaison entre les paramètres d'interception et d'éva-potranspiration, et en conséquence d'estimer de combien l'incertitude sur l'interception compense celle sur l'évapotranspiration. Ainsi, malgré une bonne correspondance entre les données d'humidité de sol observées et simulées, la modélisation inverse n'est pas faisable. Ceci reste vrai même lorsque les paramètres d'interception et le coefficient cultural sont connus, car les erreurs sur l'interception ou l'évapotranspiration sont compensées par une erreur sur la recharge. Ces erreurs n'ont pas d'effet sur l'humidité du sol. Mots-clés : test de Liaison• Cet article suggère que les paramètres de végétation ne devraient pas être estimés par optimisation sur des données d'humidité du sol.

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Section: Sink Termmentioning

confidence: 99%

Section: Transpiration Fractionmentioning

confidence: 99%

Section: Appendix: the Boundary Conditionsmentioning

confidence: 99%

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A Linking Test that establishes if groundwater recharge can be determined by optimising vegetation parameters against soil moisture

Pollacco

Braud²,

Angulo-Jaramillo

et al. 2008

Ann. For. Sci.

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“…These models are usually based on Richards' equation [6,7], which provides an appropriate tool to describe the infiltration process with a detailed description of the flow and water distribution within the soil profile [8]. Numerical solutions based on finite difference, finite element or boundary element techniques [9] have been used to solve Richards' equation. Due to the non-linearity of the described process as well as the high soil hydraulic parameters requirements, the use of numerical solutions is considered as time consuming with some stability problems [8].…”

Section: Introductionmentioning

confidence: 99%

Impact of Infiltration Process Modeling on Soil Water Content Simulations for Irrigation Management

Feki

Ravazzani

Ceppi

et al. 2018

Water

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Abstract:The uncertainty in a hydrological model, due to its structure or implemented input parameters, affects the accuracy of simulations that are usually used for important applications such as drought predictions, flood risk assessment, irrigation scheduling, ground water recharge and contamination. Several models describing soil infiltration processes have been developed. Some are analytical, while others implement numerical solutions of the Richards' equation. The objective of this work was to assess the impact of infiltration process modeling on soil water content simulations. For this study, different infiltration models were included within FEST-WB (Flash Flood Event-based Spatially-distributed rainfall-runoff Transformations-Water Balance) distributed hydrological model (SCS-CN, Green and Ampt, Philip and Ross solution). Performances of implemented infiltration models in simulating soil water content were evaluated against observations acquired in the experimental site located in a maize field in northern Italy. Soil water content was monitored together with continuous measurements of meteorological data. A sensitivity analysis was performed to assess the most important parameters governing infiltration process in the different models tested. A comparison of soil water content simulations show that Ross solution allowed the description of soil moisture variation along the vertical, but simpler lumped models provide sufficient accuracy when properly calibrated.

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“…Environmental, micro-meteorological and hydrological models are widely available for a calculation of crop water requirements at field scale. Simulation models of soil water flow have been validated in different environments (Feddes et al, 1988;Santini, 1992) and they may provide quantitative information about water balance terms of particular relevance, i.e. the recharge of aquifers and the evaporation from vegetated surfaces.…”

Section: Introductionmentioning

confidence: 99%

Current Status and Perspectives for the Estimation of Crop Water Requirements from Earth Observation

D’Urso¹

2010

Ital J Agronomy

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This paper presents an overview of current techniques and recent developments in the application of Earth Observation data for assessing crop water requirements. During recent years there has been much progress in understanding land surface-atmosphere processes and their parameterisation in the management of land and water resources. This knowledge can be combined with the potentiality of Earth Observation techniques from space, which are able to provide detailed information for monitoring agricultural systems. As today, two main developments in the field of Earth Observation data acquisition and analysis have occurred: a) availability of new generations of sensors, with enhanced spectral and spatial resolution; b) detailed knowledge of the processes that determine the response of land surface as detected from remote sensors in different regions of the electromagnetic spectrum. These advancements have made possible a "quantitative" approach in the interpretation of Earth Observation data, ready for being transferred to operative applications i.e. for irrigation scheduling and water management. This paper presents a review of current applications of optical data in the visible and near infrared spectral regions, with particular emphasis to the experiences developed by the author within AQUATER and other research projects project.

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Modelling soil water dynamics in the unsaturated zone — State of the art

Cited by 263 publications

References 69 publications

A Linking Test that establishes if groundwater recharge can be determined by optimising vegetation parameters against soil moisture

A Linking Test that establishes if groundwater recharge can be determined by optimising vegetation parameters against soil moisture

Impact of Infiltration Process Modeling on Soil Water Content Simulations for Irrigation Management

Current Status and Perspectives for the Estimation of Crop Water Requirements from Earth Observation

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