Analysis of flow and pollutant dispersion by tracer experiments in south alpine valleys

A numerical analysis of solute transport in two spatially heterogeneous fields is carried out assuming that the fields are composed of ensembles of one-dimensional non-interacting soil columns, each column representing a possible soil profile in statistical terms. The basis for the analysis is the flow simulation described in Part II (Jensen and Refsgaard, this issue), which serves as input to a transport model based on the convection-dispersion equation. The simulations of the average and variation in solute concentration in planes perpendicular to the flow direction are compared to measurements obtained from tracer experiments carried out at the two fields. Due to the limited amount of measurement data, it is difficult to draw conclusive evidence of the simulations, but reliable simulations are obtained of the mean behaviour within the two fields. The concept of equivalent soil properties is also tested for the transport problem in heterogeneous soils. Based on effective parameters for the retention and hydraulic conductivity functions it is possible to predict the mean transport in the two experimental fields.

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New Method for Estimation of Contaminant Travel Rate in Unsaturated Zone under Irrigated Soils

Water Science & Technology ◽

10.2166/wst.1993.0549 ◽

1993 ◽

Vol 27 (7-8) ◽

pp. 173-178 ◽

Cited By ~ 4

Author(s):

M. Zilberbrand

Keyword(s):

Water Content ◽

Unsaturated Zone ◽

Sandy Loam ◽

Chestnut Soil ◽

Deep Penetration ◽

Groundwater Recharge Rate ◽

Capillary Tension ◽

Travel Rate ◽

Tracer Experiments ◽

Irrigated Soils

In a thick unsaturated zone, when quick deep penetration of rain and irrigation water is absent, at the depths below 3-5 m there exists a zone of downwards quasi-steady water flow. Darcy's water velocity in this zone remains constant with depth and equal to the groundwater recharge rate; unit hydraulic head gradient occurs above the capillary fringe. Therefore, contaminant travel rate is equal to the ratio of hydraulic conductivity (K) and effective volumetric water content (θef). Field tracer experiments and laboratory K and θef determinations were carried out for several representative irrigated lots in the South Ukraine. The dependence of θef on capillary tension was studied for the first time. For loess loam with a capillary tension decreasing from 46 kPa to 0, θef nonlinearly increases from 12% to 27-28%. The effective water content portion (β1) of the total water content increases nonlinearly from 0.38 to 0.65-0.7. The β1 values were estimated for different unsaturated sedimentary rocks. For a capillary tension of about 5 kPa β1 values were: 0.88-0.99 for sands, about 0.65 for loess loam and chestnut soil, about 0.6 for sandy loam, about 0.32 for limestone and about 0.07 for clay. Calculated chloride travel rates in loess loams under irrigated soils fit the values of 0.001-0.003 m/day, determined by the results of field tracer experiments.

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RAPID AND SYNCHRONOUS DEGLACIATION OF THREE ADJACENT ALPINE VALLEYS IN THE ARKANSAS RIVER VALLEY, CO AT THE HEINRICH STADIAL 1/BØLLING TRANSITION

10.1130/abs/2019am-338629 ◽

2019 ◽

Author(s):

Joseph P. Tulenko ◽

◽

William Caffee ◽

Avriel D. Schweinsberg ◽

Jason P. Briner ◽

...

Keyword(s):

River Valley ◽

Arkansas River ◽

Alpine Valleys ◽

Arkansas River Valley

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The impact of urban block typology on pollutant dispersion

Journal of Wind Engineering and Industrial Aerodynamics ◽

10.1016/j.jweia.2021.104524 ◽

2021 ◽

Vol 210 ◽

pp. 104524

Author(s):

Fabiana Trindade da Silva ◽

Neyval Costa Reis ◽

Jane Meri Santos ◽

Elisa Valentim Goulart ◽

Cristina Engel de Alvarez

Keyword(s):

Pollutant Dispersion ◽

The Impact

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On the effects of urban-like intersections on ventilation and pollutant dispersion

Building Simulation ◽

10.1007/s12273-021-0816-5 ◽

2021 ◽

Author(s):

Xin Guo ◽

Riccardo Buccolieri ◽

Zhi Gao ◽

Mingjie Zhang ◽

Tong Lyu ◽

...

Keyword(s):

Pollutant Dispersion

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Studies on Sporopollenin Biosynthesis in Cucurbita maxima I: The Substantial Labeling of Sporopollenin from Cucurbita maxima after Application of [14C]Phenylalanine

Zeitschrift für Naturforschung C ◽

10.1515/znc-1993-1-203 ◽

1993 ◽

Vol 48 (1-2) ◽

pp. 10-15 ◽

Cited By ~ 7

Author(s):

Sabine Gubatz ◽

Rolf Wiermann

Keyword(s):

Terephthalic Acid ◽

Phthalic Acid ◽

Degradation Products ◽

Hydroxybenzoic Acid ◽

Cucurbita Maxima ◽

Purification Step ◽

Decanedioic Acid ◽

Octanedioic Acid ◽

High Level ◽

Tracer Experiments

The results of tracer experiments performed with anthers of Tulipa cv. Apeldoorn have already shown that a high level of incorporation into the sporopollenin fraction was achieved, when [14C]phenylalanine was applicated as a precursor. In order to investigate whether the substantial incorporation of [14C]phenylalanine is a unique phenomenon restricted to Tulipa, tracer experiments were carried out on anthers of Cucurbita maxima. The sporopollenin fraction was isolated and purified by a gentle method including extractions with various solvents, incubations with hydrolysing enzymes and fractionated saponifications. The remaining, as well as the released radioactivity, was determined after each purification step. After the application of [U-14C]phenylalanine, a substantial incorporation into the sporopollenin fraction was determined. The values were clearly higher than those obtained with [1-14C]glucose or those from corresponding experiments on Tulipa anthers. After potash fusion of sporopollenin fractions labeled via [U-14C]phenylalanine, p-hydroxybenzoic acid was shown to be the main com ponent among the ether soluble acids; moreover it showed the highest level of radioactivity. No radioactivity was detected in the degradation products oxalic acid, benzoic acid, phthalic acid and terephthalic acid or octanedioic acid- and decanedioic acid-dimethylester.

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