Modelling of nitrate leaching from arable land into unsaturated soil and chalk 1. Development of a management model for applications of sewage sludge and fertilizer

Andrews, Richard; Lloyd, John William; Lerner, David N.

doi:10.1016/s0022-1694(97)00009-7

Cited by 15 publications

(14 citation statements)

References 32 publications

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“…Models of solute transport for the Chalk unsaturated zone (with the exception of Andrews et al, 1997) have assumed steady state flow. The first models assumed that flow occurred exclusively in fractures while solutes diffused instantaneously into the matrix (Young et al, 1976;Oakes, 1977;Oakes et al, 1981).…”

Section: History Of Chalk Unsaturated Zone Modelsmentioning

confidence: 99%

“…However, annual rainfall represents a summation of events of intensities ranging (Grindley, 1969) (a simple soil moisture accounting model) to derive a recharge flux from precipitation data (Rushton et al, 1989;Ragab et al, 1997;Bradford et al, 2002). Andrews et al (1997) used recharge data derived from the Penman-Grindley model as the driving flow for a simple solute transport model. Nitrate was assumed to enter the matrix at a rate defined by the daily recharge with an upper limit of 0.375 cm/day (i.e., the saturated hydraulic conductivity of the matrix).…”

Section: History Of Chalk Unsaturated Zone Modelsmentioning

confidence: 99%

“…This idea is based on the hydraulic conductivity relationships observed by Wellings (1984), Hodnett and Bell (1990), Cooper et al (1990), Gardner et al (1990) and Jones and Cooper (1998). Andrews et al (1997) describe their model output as comparing well with observed solute profiles. Given the success of the much simpler, steady state flow models of Oakes et al (1981) and others at matching very similar profiles, a question arises as to how well should they compare, or even if this is the right methodology for model validation.…”

Section: History Of Chalk Unsaturated Zone Modelsmentioning

confidence: 99%

“…Given the success of the much simpler, steady state flow models of Oakes et al (1981) and others at matching very similar profiles, a question arises as to how well should they compare, or even if this is the right methodology for model validation. Andrews et al (1997) model is unsatisfactory because it implicitly assumes (without justification) that there is no solute transfer between the fractures and matrix. However, this assumption is a corollary of the initial assumption that water flowing through fractures arrives instantaneously at the water table.…”

Section: History Of Chalk Unsaturated Zone Modelsmentioning

confidence: 99%

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Transient simulations of flow and transport in the Chalk unsaturated zone

Mathias

Butler

Jackson

et al. 2006

Journal of Hydrology

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Section: History Of Chalk Unsaturated Zone Modelsmentioning

confidence: 99%

Section: History Of Chalk Unsaturated Zone Modelsmentioning

confidence: 99%

Section: History Of Chalk Unsaturated Zone Modelsmentioning

confidence: 99%

Section: History Of Chalk Unsaturated Zone Modelsmentioning

confidence: 99%

See 2 more Smart Citations

Transient simulations of flow and transport in the Chalk unsaturated zone

Mathias

Butler

Jackson

et al. 2006

Journal of Hydrology

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“…Il y a cependant des risques associés à ces pratiques culturales puisque l'utilisation excessive des engrais chimiques et organiques peut entraîner le lessivage de nitrates vers l'eau souterraine (REFSGAARD et al, 1999). Partout dans le monde, des observations et des études indiquent un lien étroit entre l'agriculture intensive et les fortes concentrations en nitrates dans l'eau souterraine (PRIMEAU et GRIMARD, 1989;BERGSTRÖM et JARVIS, 1991;ANDREWS et al, 1997;LASSERRE et al, 1999;SIDD, 2003).…”

Section: Introductionunclassified

Vulnérabilité de l’eau souterraine à la contamination par les nitrates sur le bassin versant de la rivière Noire (Montérégie, Québec)

Bolduc

Larocque²,

Prichonnet³

2006

rseau

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Résumé La rivière Yamaska est l’un des affluents du Saint-Laurent les plus contaminés par les activités agricoles. Cette problématique touche particulièrement le sous-bassin de la rivière Noire où les dépôts de surface du Quaternaire sont discontinus, de faible épaisseur et souvent perméables. L’objectif de cette étude est de déterminer la vulnérabilité de l’eau souterraine sur une partie du sous-bassin de la rivière Noire (100 km2). La méthodologie utilisée comprend la caractérisation de l’aquifère, l’analyse des concentrations en nitrates et des contenus en δ18O, l’étude de la vulnérabilité en utilisant l’approche AQUIPRO et la modélisation hydrogéologique. Les résultats montrent une dégradation significative et d’origine anthropique de l’eau souterraine : plusieurs concentrations excèdent 1 mg N-NO3/L et quelques-unes excèdent 10 mg N-NO3/L. Les puits contaminés sont situés sur les crêtes topographiques où le silt argileux est absent et le till discontinu, et où la plus grande vulnérabilité AQUIPRO a été identifiée. Une diminution des concentrations avec la profondeur de prélèvement s’explique par un écoulement souterrain peu profond entraînant les nitrates vers un ruisseau et vers la rivière Noire. La vulnérabilité de l’eau souterraine est ainsi beaucoup plus grande dans les couches superficielles du roc fracturé. Le temps moyen de séjour de l’eau souterraine est estimé à 20 ans. Les concentrations mesurées permettent d’établir un lien direct entre la vulnérabilité, les dépôts de surface, la stratigraphie du substrat et les directions de l’écoulement souterrain. Elles démontrent aussi la présence d’une contamination de l’eau souterraine par les nitrates qui est susceptible d’augmenter si aucune mesure préventive n’est mise en place.

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Prediction of the arrival of peak nitrate concentrations at the water table at the regional scale in Great Britain

Wang

Stuart

Bloomfield

et al. 2011

Hydrological Processes

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Abstract:A simple process-based approach to predict regional-scale loading of nitrate at the water table was implemented in a GIS for Great Britain. This links a nitrate input function, unsaturated zone thickness and lithologically-dependent rate of nitrate unsaturated zone travel to estimate arrival time of nitrate at the water table. The nitrate input function is the loading at the base of the soil and has been validated using unsaturated zone pore-water profiles. The unsaturated zone thickness uses groundwater levels based on regional-scale observations infilled by interpolated river base levels. Estimates of the rate of unsaturated zone travel are attributed from regional-scale hydrogeological mapping. The results indicate that peak nitrate loading may have already arrived at the water table for many aquifers, but that it has not where the unsaturated zone is relatively thick There are contrasting outcomes for the two main aquifers which have similar unsaturated zone velocities, the predominantly low relief Permo-Triassic sandstones and the Chalk, which forms significant topographic features. For about 60% of the Chalk, the peak input has not yet reached the water table and will continue to arrive over the next 60 years. The methodology is readily transferable and provides a robust method for estimating peak arrival time for any diffuse conservative pollutant where an input function can be defined at a regional scale and requires only depth to groundwater and a hydrogeological classification. The methodology is extendable in that if additional information is available this can easily be incorporated into the model scheme.

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Modelling of nitrate leaching from arable land into unsaturated soil and chalk 1. Development of a management model for applications of sewage sludge and fertilizer

Cited by 15 publications

References 32 publications

Transient simulations of flow and transport in the Chalk unsaturated zone

Transient simulations of flow and transport in the Chalk unsaturated zone

Vulnérabilité de l’eau souterraine à la contamination par les nitrates sur le bassin versant de la rivière Noire (Montérégie, Québec)

Prediction of the arrival of peak nitrate concentrations at the water table at the regional scale in Great Britain

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