Solute transport characteristics of a deep soil profile in the Loess Plateau, China
Jiao WANG1,2, Ming'an SHAO1,2,3,*()
1 Key Laboratory of Ecosystems Network Observation and Modeling, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2 University of Chinese Academy of Sciences, Beijing 100049, China 3 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China
Understanding solute transport behaviors of deep soil profile in the Loess Plateau is helpful for ecological construction and agricultural production improvement. In this study, solute transport processes of a deep soil profile were measured by a conservative tracer experiment using 25 undisturbed soil cores (20 cm long and 7 cm diameter for each) continuously sampled from the surface downward to the depth of 500 cm in the Loess Plateau of China. The solute transport breakthrough curves (BTCs) were analyzed in terms of the convection-dispersion equation (CDE) and the mobile-immobile model (MIM). Average pore-water velocity and dispersion coefficient (or effective dispersion coefficient) were calculated using the CDE and MIM. Basic soil properties and water infiltration parameters were also determined to explore their influence on the solute transport parameters. Both pore-water velocity and dispersion coefficient (or effective dispersion coefficient) generally decreased with increasing depth, and the dispersivity fluctuated along the soil profile. There was a good linear correlation between log-transformed pore-water velocity and dispersion coefficient, with a slope of about 1.0 and an average dispersivity of 0.25 for the entire soil profile. Generally speaking, the soil was more homogeneous along the soil profile. Our results also show that hydrodynamic dispersion is the dominant mechanism of solute transport of loess soils in the study area.
. [J]. 干旱区科学, 2018, 10(4): 628-637.
Jiao WANG, Ming'an SHAO. Solute transport characteristics of a deep soil profile in the Loess Plateau, China. Journal of Arid Land, 2018, 10(4): 628-637.
Bear J.1972. Dynamics of Fluid in Porous Media. New York: Elsevier, 174-175.
[2]
Beven K J, Henderson D E, Reeves A D.1993. Dispersion parameters for undisturbed partially saturated soil. Journal of Hydrology, 143(1-2): 19-43.
[3]
Chotpantarat S, Ong S K, Sutthirat C, et al.2012. Competitive modeling of sorption and transport of Pb2+, Ni2+, Mn2+ and Zn2+ under binary and multi-metal systems in lateritic soil columns. Geoderma, 189-190: 278-287.
[4]
Fu B J, Chen L D, Ma K M, et al.2000. The relationships between land use and soil conditions in the hilly area of the loess plateau in northern Shaanxi, China. CATENA, 39(1): 69-78.
[5]
Gao G Y, Zhan H B, Feng S Y, et al.2010. A new mobile-immobile model for reactive solute transport with scale-dependent dispersion. Water Resources Research, 46(8): W08533.
[6]
Gao L, Shao M A, Peng X H, et al.2015. Spatio-temporal variability and temporal stability of water contents distributed within soil profiles at a hillslope scale. CATENA, 132: 29-36.
[7]
Garré S, Koestel J, Günther T, et al.2010. Comparison of heterogeneous transport processes observed with electrical resistivity tomography in two soils. Vadose Zone Journal, 9(2): 336-349.
[8]
Heathman G C, Starks P J, Ahuja L R, et al.2003. Assimilation of surface soil moisture to estimate profile soil water content. Journal of Hydrology, 279(1-4): 1-17.
[9]
Huang K, Toride N, Van Genuchten M T.1995. Experimental investigation of solute transport in large, homogeneous and heterogeneous, saturated soil columns. Transport in Porous Media, 18(3): 283-302.
[10]
Jaynes D B, Rice R C, Bowman R S.1988. Transport of a conservative tracer in the field under continuous flood irrigation. Soil Science Society of America Journal, 52(3): 618-624.
[11]
Jiang Y L, Zhou B B, Shao M A, et al.2012. Simulating the chloride transport in a loess plateau soil with two-region model and two-flow domain model. Journal of Soil and Water Conservation, 26(5): 224-228, 234. (in Chinese)
[12]
Jiao F, Wen Z M, An S S.2011. Changes in soil properties across a chronosequence of vegetation restoration on the Loess Plateau of China. CATENA, 86(2): 110-116.
[13]
Jury W A.1985. Spatial variability of soil physical parameters in solute migration: a critical literature review. In: University of California. EPRI-EA-4228. Riverside, USA.
[14]
Kang S Z, Zhang L, Liang Y L, et al.2002. Effects of limited irrigation on yield and water use efficiency of winter wheat in the Loess Plateau of China. Agricultural Water Management, 55(3): 203-216.
[15]
Koestel J K, Norgaard T, Luong N M, et al.2013. Links between soil properties and steady-state solute transport through cultivated topsoil at the field scale. Water Resources Research, 49(2): 790-807.
[16]
Lapidus L, Amundson N R.1952. Mathematics of adsorption in beds. VI. The effect of longitudinal diffusion in ion exchange and chromatographic columns. The Journal of Physical Chemistry, 56(8): 984-988.
[17]
Lennartz B.1999. Variation of herbicide transport parameters within a single field and its relation to water flux and soil properties. Geoderma, 91(3-4): 327-345.
[18]
Li X Z, Shao M A, Jia X X, et al.2015. Landscape-scale temporal stability of soil water storage within profiles on the semiarid Loess Plateau of China. Journal of Soils and Sediments, 15(4): 949-961.
[19]
Li X Z, Shao M A, Jia X X, et al.2016. Profile distribution of soil-water content and its temporal stability along a 1340-m long transect on the Loess Plateau, China. CATENA, 137: 77-86.
[20]
Mallants D, Vanclooster M, Meddahi M, et al.1994. Estimating solute transport in undisturbed soil columns using time-domain reflectometry. Journal of Contaminant Hydrology, 17(2): 91-109.
[21]
Mallants D.2014. Field-scale solute transport parameters derived from tracer tests in large undisturbed soil columns. Soil Research, 52(1): 13-26.
[22]
Nielsen D R, Biggar J W.1962. Miscible displacement: III. Theoretical considerations. Soil Science Society of America Journal, 26(3): 216-221.
[23]
Parker J C, Valocchi A J.1986. Constraints on the validity of equilibrium and first-order kinetic transport models in structured soils. Water Resources Research, 22(3): 399-407.
[24]
Saffman P G.1959. A theory of dispersion in a porous medium. Journal of Fluid Mechanics, 6(3): 321-349.
[25]
Seuntjens P, Mallants D, Šimůnek J, et al.2002. Sensitivity analysis of physical and chemical properties affecting field-scale cadmium transport in a heterogeneous soil profile. Journal of Hydrology, 264(1-4): 185-200.
[26]
Seyfried M S, Rao P S C.1987. Solute transport in undisturbed columns of an aggregated tropical soil: Preferential flow effects. Soil Science Society of America Journal, 51(6): 1434-1444.
[27]
Shao M, Horton R, Miller R K.1998. An approximate solution to the convection-dispersion equation of solute transport in soil. Soil Science, 163(5): 339-345.
[28]
Shi H, Shao M A.2000. Soil and water loss from the Loess Plateau in China. Journal of Arid Environments, 45(1): 9-20.
[29]
Toride N, Leij F, Van Genuchten M T. 1995. The CXTFIT code for estimating transport parameters from laboratory or field tracer experiments. In: US Salinity Laboratory. Research Report No. 137. Riverside, California.
[30]
Tsuboyama Y, Sidle R C, Noguchi S, et al.1994. Flow and solute transport through the soil matrix and macropores of a hillslope segment. Water Resources Research, 30(4): 879-890.
[31]
van der Zee S E A T M, Leijnse A. 2013. Solute transport in soil. In: Soriano M C H. Soil Processes and Current Trends in Quality Assessment. Rijeka, Croatia:InTech ., 34-86.
[32]
van Genuchten M T, Wierenga P J.1976. Mass transfer studies in sorbing porous media I. Analytical solutions. Soil Science Society of America Journal, 40(4): 473-480.
[33]
van Genuchten M T, Dalton F N.1986. Models for simulating salt movement in aggregated field soils. Geoderma, 38(1-4): 165-183.
[34]
van Genuchten M T, Wagenet R J.1989. Two-site/two-region models for pesticide transport and degradation: Theoretical development and analytical solutions. Soil Science Society of America Journal, 53(5): 1303-1310.
[35]
Vanclooster M, Mallants D, Vanderborght J, et al.1995. Monitoring solute transport in a multi-layered sandy lysimeter using time domain reflectometry. Soil Science Society of America Journal, 59(2): 337-344.
[36]
Venkatraman A, Hesse M A, Lake L W, et al.2014. Analytical solutions for flow in porous media with multicomponent cation exchange reactions. Water Resources Research, 50(7): 5831-5847.
[37]
Wang F, Bian Y R, Jiang X, et al.2006. Residual characteristics of organochlorine pesticides in Lou soils with different fertilization modes. Pedosphere, 16(2): 161-168.
[38]
Wang H F, Shao M A.2007. Experimental study of non-reactive anion transport in the soil-stone mixture. Advances in Water Science, 18(2): 164-169. (in Chinese)
[39]
Wang R, Liu W Z, Li Z.2008. Physical properties of soils along a 10 m deep soil profile in loess tableland. Acta Pedologica Sinica, 45(3): 550-554. (in Chinese)
[40]
Wang Y Q, Shao M A, Liu Z P.2013. Vertical distribution and influencing factors of soil water content within 21-m profile on the Chinese Loess Plateau. Geoderma, 193-194: 300-310.
[41]
Yang T, Wang Q J, Zhou B B, et al.2013. Preferential solute transport in a loess silt loam soil. Soil Science, 178(4): 157-164.
[42]
Zhou B B, Shao M A, Wang Q J, et al.2011. Effects of different rock fragment contents and sizes on solute transport in soil columns. Vadose Zone Journal, 10(1): 386-393.
[43]
Zhou Z C, Gan Z T, Shangguan Z P, et al.2010. Effects of grazing on soil physical properties and soil erodibility in semiarid grassland of the Northern Loess Plateau (China). CATENA, 82(2): 87-91.
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