ESTIMATING SOLUTE TRANSPORT IN UNDISTURBED SOIL COLUMNS USING TIME-DOMAIN REFLECTOMETRY

被引:86
作者
MALLANTS, D
VANCLOOSTER, M
MEDDAHI, M
FEYEN, J
机构
[1] Institute for Land and Water Management, Faculty of Agricultural Sciences, Katholieke Universiteit Leuven
关键词
D O I
10.1016/0169-7722(94)90016-7
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Time-domain reflectometry (TDR) was used to monitor solute breakthrough curves (BTC's) in 30 saturated undisturbed soil columns collected along a 35-m-long transect in the field. The BTC's were obtained by relating the bulk soil electrical conductivity, EC(a), to the relative concentration of a KCl solute pulse applied to the soil surface. Values of EC(a) were estimated by measuring the soil's impedance to an electromagnetic wave generated by a cable tester. Parallel two-rod TDR probes inserted horizontally at a depth of 10 cm were used to monitor the soil's impedance during transport of the KCl solute pulse. Calculated experimental time moments indicated that the BTC data were very variable in time and space. This variability was attributed in part to the relatively small volume of soil sampled with the TDR probes, and in part to the natural heterogeneity of the sandy loam soil. The observed BTC's were classified into three groups. One group showed bell-shaped curves consistent with the classical convection-dispersion equation (CDE). A second group was characterized by early breakthrough and long tailing. The BTC's in this group could be described by a mobile-immobile transport model (MIM). A third group of BTC's showed irregular shapes with several peaks. Time moments were used to compare the estimated (from the moments), fitted (CDE and MIM) and independently measured pore-water velocities. The disparities between the observed and fitted velocities suggest that for structured soil several TDR probes may be necessary in order to obtain reasonable estimates of column-scale solute transport behaviour.
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页码:91 / 109
页数:19
相关论文
共 31 条
[1]   SOIL NITRATE-NITROGEN DETERMINED BY CORING AND SOLUTION EXTRACTION TECHNIQUES [J].
ALBERTS, EE ;
BURWELL, RE ;
SCHUMAN, GE .
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, 1977, 41 (01) :90-92
[2]  
BIGGAR J. W., 1962, SOIL SCI SOC AMER PROC, V26, P125
[3]   METHODOLOGY FOR NITROGEN TRANSFORMATION AND BALANCE IN SOIL [J].
BROADBENT, FE .
PLANT AND SOIL, 1981, 58 (1-3) :383-399
[4]   FIELD SCALE TRANSPORT OF BROMIDE IN AN UNSATURATED SOIL .1. EXPERIMENTAL METHODOLOGY AND RESULTS [J].
BUTTERS, GL ;
JURY, WA ;
ERNST, FF .
WATER RESOURCES RESEARCH, 1989, 25 (07) :1575-1581
[5]   THE TIME-DOMAIN REFLECTOMETRY METHOD FOR MEASURING SOIL-WATER CONTENT AND SALINITY [J].
DALTON, FN ;
VANGENUCHTEN, MT .
GEODERMA, 1986, 38 (1-4) :237-250
[6]   A 3-DIMENSIONAL FIELD-STUDY OF SOLUTE TRANSPORT THROUGH UNSATURATED, LAYERED, POROUS-MEDIA .1. METHODOLOGY, MASS RECOVERY, AND MEAN TRANSPORT [J].
ELLSWORTH, TR ;
JURY, WA ;
ERNST, FF ;
SHOUSE, PJ .
WATER RESOURCES RESEARCH, 1991, 27 (05) :951-965
[7]   PARAMETER ESTIMATES OF FIELD SOLUTE TRANSPORT MODELS BASED ON TIME DOMAIN REFLECTOMETRY MEASUREMENTS [J].
ELRICK, DE ;
KACHANOSKI, RG ;
PRINGLE, EA ;
WARD, AL .
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, 1992, 56 (06) :1663-1666
[8]   VALIDITY OF SOIL-WATER SAMPLES COLLECTED WITH POROUS CERAMIC CUPS [J].
HANSEN, EA ;
HARRIS, AR .
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, 1975, 39 (03) :528-536
[9]   A COMPUTER-CONTROLLED 36-CHANNEL TIME DOMAIN REFLECTOMETRY SYSTEM FOR MONITORING SOIL-WATER CONTENTS [J].
HEIMOVAARA, TJ ;
BOUTEN, W .
WATER RESOURCES RESEARCH, 1990, 26 (10) :2311-2316
[10]   A FIELD-TEST OF THE TRANSFER-FUNCTION MODEL FOR PREDICTING SOLUTE TRANSPORT [J].
JURY, WA ;
STOLZY, LH ;
SHOUSE, P .
WATER RESOURCES RESEARCH, 1982, 18 (02) :369-375