On the value of soil moisture measurements in vadose zone hydrology: A review

Water Resources Research

Volumn 46, Issue 4, 2008, Pages

  Vereecken, H ^a   Huisman, J A ^a   Bogena, H ^a   Vanderborght, J ^a   Vrugt, J A ^b   Hopmans, J W ^c  

^a FORSCHUNGSZENTRUM JÜLICH   (Germany)

^b CENTER FOR NONLINEAR STUDIES   (United States)

^c UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CATCHMENTS; GROUNDWATER; MOISTURE DETERMINATION; MOISTURE METERS; REMOTE SENSING; SOIL MOISTURE;

DATA ASSIMILATION METHODS; HYDROLOGICAL MODELS; MEASUREMENT TECHNIQUES; SOIL HYDRAULIC PROPERTIES; SOIL MOISTURE MEASUREMENT; SPATIAL AND TEMPORAL RESOLUTIONS; VADOSE ZONE HYDROLOGY; WATER AND ENERGY FLUXES;

SOIL SURVEYS;

CATCHMENT; DATA ASSIMILATION; DATABASE; ENERGY FLUX; HYDROGEOLOGY; LITERATURE REVIEW; REMOTE SENSING; SOIL MOISTURE; SPATIOTEMPORAL ANALYSIS; VADOSE ZONE; WATER FLOW;

EID: 79551694368     PISSN: 00431397     EISSN: None     Source Type: Journal    
DOI: 10.1029/2008WR006829     Document Type: Article

References (297)

1. Abbaspour, K. C., M. T. van Genuchten, R. Schulin, and E. Schlappi (1997), A sequential uncertainty domain inverse procedure for estimating subsurface flow and transport parameters, Water Resour. Res., 33, 1879-1892, doi:10.1029/97WR01230.
2. Abbaspour, K. C., M. A. Sonnleitner, and R. Schulin (1999), Uncertainty in estimation of soil hydraulic parameters by inverse modeling: Example lysimeter experiments, Soil Sci. Soc. Am. J., 63, 501-509.
3. Abbaspour, K., R. Kasteel, and R. Schulin (2000), Inverse parameter estimation in a layered unsaturated field soil, Soil Sci., 165, 109-123, doi:10.1097/00010694-200002000-00002.
4. Abbaspour, K. C., R. Schulin, and M. T. van Genuchten (2001), Estimating unsaturated soil hydraulic parameters using ant colony optimization, Adv. Water Resour., 24, 827-841, doi:10.1016/S0309-1708 (01) 00018-5.
5. Ahuja, L. R., O. Wendroth, and D. R. Nielsen (1993), Relationship between initial drainage of surface soil and average profile saturated conductivity, Soil Sci. Soc. Am. J., 57, 19-25.
6. Akbar, M. A., A. L. Kenimer, S. W. Searcy, and H. A. Torbert (2005), Soil water estimation using electromagnetic induction, Trans. ASAE, 48, 129-135.
7. Albertson, J. D., and N. Montaldo (2003), Temporal dynamics of soil moisture variability: 1. Theoretical basis, Water Resour. Res., 39(10), 1274, doi:10.1029/2002WR001616.
8. Alessi, R. S., and L. Prunty (1986), Soil water determination using fiber optics, Soil Sci. Soc. Am. J., 50, 860-863.
9. Altese, E., O. Bolognani, M. Mancini, and P. A. Troch (1996), Retrieving soil moisture over bare soil from ERS 1 synthetic aperture radar data: Sensitivity analysis based on a theoretical surface scattering model and field data, Water Resour. Res., 32, 653-661, doi:10.1029/95WR03638.
10. Andreu, L., J. W. Hopmans, and L. J. Schwankl (1997), Spatial and temporal distribution of soil water balance for a drip-irrigated almond tree, Agric. Water Manage., 35, 123-146, doi:10.1016/S0378-3774 (97) 00018-8.
11. Annan, J. D., D. J. Lunt, J. C. Hargreaves, and P. J. Valdes (2005), Parameter estimation in an atmospheric GCM using the ensemble Kalman filter, Nonlinear Processes Geophys., 12, 363-371.
12. Arya, L. M., J. C. Richter, and J. F. Paris (1983), Estimating profile water storage from surface zone soil-moisture measurements under bare field conditions, Water Resour. Res., 19, 403-412, doi:10.1029/WR019i002p00403.
13. Aubert, D., C. Loumagne, L. Oudin, and S. Le Hégarat-Mascle (2003), Assimilation of soil moisture into hydrological models: The sequential method, Can. J. Rem. Sens., 29, 711-717.
14. Bakker, G., M. J. van der Ploeg, G. H. de Rooij, C. W. Hoogendam, H. P. A. Gooren, C. Huiskes, L. K. Koopal, and H. Kruidhof (2007), New polymer tensiometers: Measuring matric pressures down to the wilting point, Vadose Zone J., 6, 196-202, doi:10.2136/vzj2006.0110. (Pubitemid 47252340)
15. Balsamo, G., F. Bouyssel, and J. Noilhan (2004), A simplified bidimensional variational analysis of soil moisture from screen-level observations in a mesoscale numerical weather-prediction model, Q. J. R. Meteorol. Soc., 130, 895-915, doi:10.1256/qj.02.215. (Pubitemid 38546621)
16. Bell, J. P., T. J. Dean, and M. G. Hodnett (1987), Soil-moisture measurement by an improved capacitance technique. 2. Field techniques, evaluation and calibration, J. Hydrol., 93, 79-90, doi:10.1016/0022-1694 (87) 90195-8.
17. Bernard, R., M. Vauclin, and D. Vidalmadjar (1981), Possible use of active microwave remote-sensing data for prediction of regional evaporation by numerical-simulation of soil-water movement in the unsaturated zone, Water Resour. Res., 17, 1603-1610, doi:10.1029/WR017i006p01603.
18. Bernard, R., J. V. Soares, and D. Vidalmadjar (1986), Differential bare field drainage properties from airborne microwave observations, Water Resour. Res., 22, 869-875, doi:10.1029/WR022i006p00869.
19. Bertino, L., G. Evensen, and H. Wackernagel (2003), Sequential data assimilation techniques in oceanography, Int. Stat. Rev., 71, 223-241.
20. Biftu, G. F., and T. Y. Gan (1999), Retrieving near-surface soil moisture from Radarsat SAR data, Water Resour. Res., 35, 1569-1579, doi:10.1029/ 1998WR900120. (Pubitemid 29207990)
21. Binley, A., G. Cassiani, R. Middleton, and P. Winship (2002), Vadose zone flow model parameterisation using cross-borehole radar and resistivity imaging, J. Hydrol., 267, 147-159, doi:10.1016/S0022-1694 (02) 00146-4.
22. Blonquist, J. M., Jr., S. B. Jones, and D. A. Robinson (2005a), Standardizing characterization of electromagnetic water content sensors: Part 2. Evaluation of seven sensing systems, Vadose Zone J., 4, 1059-1069, doi:10.2136/vzj2004.0141.
23. Blonquist, J. M., Jr., S. B. Jones, and D. A. Robinson (2005b), A time domain transmission sensor with TDR performance characteristics, J. Hydrol., 314, 235-245, doi:10.1016/j.jhydrol.2005.04.005. (Pubitemid 41727784)
24. Blöschl, G., and M. Sivapalan (1995), Scale issues in hydrological modeling-A review, Hydrol. Processes, 9, 251-290, doi:10.1002/hyp. 3360090305.
25. Blumberg, D. G., G. Ronen, J. Ben-Asher, V. Freilikher, L. D. Vulfson, and A. L. Kotlyar (2006), Utilizing a P-band scatterometer to assess soil water saturation percent of a bare sandy soil, J. Hydrol., 318, 374-378, doi:10.1016/j.jhydrol.2005.06.023. (Pubitemid 43120806)
26. Bogena, H., K. Schulz, and H. Vereecken (2006), Towards a network of observatories in terrestrial environmental research, Adv. Geosci., 9, 1-6.
27. Bogena, H. R., J. A. Huisman, C. Oberstdörster, and H. Vereecken (2007), Evaluation of a low-cost soil water content sensor for wireless network applications, J. Hydrol., 344, 32-42, doi:10.1016/j.jhydrol.2007.06.032. (Pubitemid 47362141)
28. Botter, G., A. Porporato, I. Rodriguez-Iturbe, and A. Rinaldo (2007), Basinscale soil moisture dynamics and the probabilistic characterization of carrier hydrologic flows: Slow, leaching-prone components of the hydrologic response, Water Resour. Res., 43, W02417, doi:10.1029/2006WR005043. (Pubitemid 46502884)
29. Boulet, G., A. Chehbouni, I. Braud, M. Vauclin, R. Haverkamp, and C. Zammit (2000), A simple water and energy balance model designed for regionalization and remote sensing data utilization, Agric. For. Meteorol., 105, 117-132, doi:10.1016/S0168-1923 (00) 00184-2.
30. Brocca, L., R. Morbidelli, F. Melone, and T. Moramarco (2007), Soil moisture spatial variability in experimental areas of central Italy, J. Hydrol., 333, 356-373, doi:10.1016/j.jhydrol.2006.09.004. (Pubitemid 46053965)
31. Bronstert, A., and E. J. Plate (1997), Modelling of runoff generation and soil moisture dynamics for hill slopes and micro-catchments, J. Hydrol., 198, 177-195, doi:10.1016/S0022-1694 (96) 03306-9.
32. Buttafuoco, G., and A. Castrignano (2005), Study of the spatio-temporal variation of soil moisture under forest using intrinsic random functions of order k, Geoderma, 128, 208-220, doi:10.1016/j.geoderma.2005.04.004. (Pubitemid 41127229)
33. Calvet, J.-C., and J. Noilhan (2000), From near-surface to root-zone soil moisture using year-round data, J. Hydrometeorol., 1, 393-411, doi:10.1175/1525-7541 (2000) 001<0393:FNSTRZ>2.0.CO;2.
34. Calvet, J. C., J. Noilhan, and P. Bessemoulin (1998), Retrieving the rootzone soil moisture from surface soil moisture or temperature estimates: A feasibility study based on field measurements, J. Appl. Meteorol., 37, 371-386, doi:10.1175/1520-0450 (1998) 037<0371:RTRZSM>2.0.CO;2.
35. Camillo, P., and T. J. Schmugge (1983), Estimating soil-moisture storage in the root zone from surface measurements, Soil Sci., 135, 245-264, doi:10.1097/00010694-198304000-00006.
36. Capehart, W. J., and T. N. Carlson (1997), Decoupling of surface and nearsurface soil water content: A remote sensing perspective, Water Resour. Res., 33, 1383-1395, doi:10.1029/97WR00617.
37. Cardell-Oliver, R., M. Kranz, K. Smettem, and K. Mayer (2005), A reactive soil moisture sensor network: Design and field evaluation, Int. J. Distrib. Sensor Networks, 1, 149-162, doi:10.1080/15501320590966422.
38. Ceballos, A., K. Scipal, W. Wagner, and J. Martinez-Fernandez (2005), Validation of ERS scatterometer-derived soil moisture data in the central part of the Duero Basin, Spain, Hydrol. Processes, 19, 1549-1566, doi:10.1002/hyp. 5585.
39. Chang, D.-H., and S. Islam (2000), Estimation of soil physical properties using remote sensing and artificial neural network, Remote Sens. Environ., 74, 534-544, doi:10.1016/S0034-4257 (00) 00144-9.
40. Chang, D.-H., R. Kothari, and S. Islam (2003), Classification of soil texture using remotely, sensed brightness temperature over the Southern Great Plains, IEEE Trans. Geosci. Remote Sens., 41, 664-674, doi:10.1109/TGRS.2003. 809935.
41. Chen, J. Y., J. W. Hopmans, and G. E. Fogg (1995), Sampling design for soil-moisture measurements in large field trials, Soil Sci., 159, 155-161.
42. Choi, M., and J. M. Jacobs (2007), Soil moisture variability of root zone profiles within SMEX02 remote sensing footprints, Adv. Water Resour., 30, 883-896, doi:10.1016/j.advwatres.2006.07.007.
43. Choi, M., J. M. Jacobs, and H. H. Cosh (2007), Scaled spatial variability of soil moisture fields, Geophys. Res. Lett., 34, L01401, doi:10.1029/ 2006GL028247. (Pubitemid 47277728)
44. Clemente, R. S., R. Dejong, H. N. Hayhoe, W. D. Reynolds, and M. Hares (1994), Testing and comparison of three unsaturated soil-water flow models, Agric. Water Manage., 25, 135-152, doi:10.1016/0378-3774 (94) 90041-8.
45. Coelho, E. F., and D. Or (1998), Root distribution and water uptake patterns of corn under surface and subsurface drip irrigation, Plant Soil, 206, 123-136, doi:10.1023/A:1004325219804. (Pubitemid 29235353)
46. Comegna, V., and A. Basile (1994), Temporal stability of spatial patterns of soil-water storage in a cultivated Vesuvian soil, Geoderma, 62, 299-310, doi:10.1016/0016-7061 (94) 90042-6.
47. Coronato, F. R., and M. B. Bertiller (1996), Precipitation and landscape related effects on soil moisture in semi-arid rangelands of Patagonia, J. Arid Environ., 34, 1-9, doi:10.1006/jare.1996.0088. (Pubitemid 26380894)
48. Corwin, D. L., and S. M. Lesch (2005), Characterizing soil spatial variability with apparent soil electrical conductivity I. Survey protocols, Comput. Electron. Agric., 46, 103-133, doi:10.1016/j.compag.2004.11.002. (Pubitemid 40257067)
49. Cosh, M. H., T. J. Jackson, R. Bindlish, and J. H. Prueger (2004), Watershed scale temporal and spatial stability of soil moisture and its role in validating satellite estimates, Remote Sens. Environ., 92, 427-435, doi:10.1016/j.rse.2004.02.016. (Pubitemid 39204626)
50. Cosh, M. H., T. J. Jackson, P. Starks, and G. Heathman (2006), Temporal stability of surface soil moisture in the Little Washita River watershed and its applications in satellite soil moisture product validation, J. Hydrol., 323, 168-177, doi:10.1016/j.jhydrol.2005.08.020. (Pubitemid 44250823)
51. Crosson, W. L., A. S. Limaye, and C. A. Laymon (2005), Parameter sensitivity of soil moisture retrievals from airborne C-and X-band radiometer measurements in SMEX02, IEEE Trans. Geosci. Remote Sens., 43, 2842-2853, doi:10.1109/TGRS.2005.857916. (Pubitemid 41788549)
52. Crow, W. T., and E. F. Wood (2002a), Impact of soil moisture aggregation on surface energy flux prediction during SGP'97, Geophys. Res. Lett., 29(1), 1008, doi:10.1029/2001GL013796.
53. Crow, W. T., and E. F. Wood (2002b), The value of coarse-scale soil moisture observations for regional surface energy balance modeling, J. Hydrometeorol., 3, 467-482, doi:10.1175/1525-7541 (2002) 003<0467:TVOCSS> 2.0.CO;2.
54. Crow, W. T., and E. F. Wood (2003), The assimilation of remotely sensed soil brightness temperature imagery into a land surface model using ensemble Kalman filtering: A case study based on ESTAR measurements during SGP97, Adv. Water Resour., 26, 137-149, doi:10.1016/S0309-1708 (02) 00088-X.
55. Crow, W. T., R. Bindlish, and T. J. Jackson (2005a), The added value of spaceborne passive microwave soil moisture retrievals for forecasting rainfall-runoff partitioning, Geophys. Res. Lett., 32, L18401, doi:10.1029/2005GL023543. (Pubitemid 41582560)
56. Crow, W. T., D. Ryu, and J. S. Famiglietti (2005b), Upscaling of field-scale soil moisture measurements using distributed land surface modeling, Adv. Water Resour., 28, 1-14, doi:10.1016/j.advwatres.2004.10.004. (Pubitemid 40077363)
57. Dane, J., and S. Hruska (1983), In-situ determination of soil hydraulic properties during drainage, Soil Sci. Soc. Am. J., 47, 619-624.
58. Das, N. N., and B. P. Mohanty (2006), Root zone soil moisture assessment using remote sensing and vadose zone modeling, Vadose Zone J., 5, 296-307, doi:10.2136/vzj2005.0033. (Pubitemid 47254037)
59. Dean, T. J., J. P. Bell, and A. J. B. Baty (1987), Soil-moisture measurement by an improved capacitance technique. 1. Sensor design and performance, J. Hydrol., 93, 67-78, doi:10.1016/0022-1694 (87) 90194-6.
60. Decharme, B., and H. Douville (2007), Global validation of the ISBA subgrid hydrology, Clim. Dyn., 29, 21-37, doi:10.1007/s00382-006-0216-7. (Pubitemid 46746419)
61. De Lannoy, G. J. M., N. E. C. Verhoest, P. R. Houser, T. J. Gish, and M. Van Meirvenne (2006), Spatial and temporal characteristics of soil moisture in an intensively monitored agricultural field (OPE3), J. Hydrol., 331, 719-730, doi:10.1016/j.jhydrol.2006.06.016. (Pubitemid 44709059)
62. De Lannoy, G. J. M., P. R. Houser, V. R. N. Pauwels, and N. E. C. Verhoest (2007), State and bias estimation for soil moisture profiles by an ensemble Kalman filter: Effect of assimilation depth and frequency, Water Resour. Res., 43, W06401, doi:10.1029/2006WR005100. (Pubitemid 47124424)
63. Demarty, J., C. Ottle, I. Braud, A. Olioso, J. P. Frangi, L. A. Bastidas, and H. V. Gupta (2004), Using a multiobjective approach to retrieve information on surface properties used in a SVAT model, J. Hydrol., 287, 214-236, doi:10.1016/j.jhydrol.2003.10.003. (Pubitemid 38300329)
64. Demarty, J., C. Ottle, I. Braud, A. Olioso, J. P. Frangi, H. V. Gupta, and L. A. Bastidas (2005), Constraining a physically based Soil-Vegetation- Atmosphere Transfer model with surface water content and thermal infrared brightness temperature measurements using a multiobjective approach, Water Resour. Res., 41, W01011, doi:10.1029/2004WR003695. (Pubitemid 40359291)
65. Drusch, M., E. F. Wood, H. Gao, and A. Thiele (2004), Soil moisture retrieval during the Southern Great Plains Hydrology Experiment 1999: A comparison between experimental remote sensing data and operational products, Water Resour. Res., 40, W02504, doi:10.1029/2003WR002441.
66. Dunne, S., and D. Entekhabi (2005), An ensemble-based reanalysis approach to land data assimilation, Water Resour. Res., 41, W02013, doi:10.1029/ 2004WR003449. (Pubitemid 40393932)
67. Eching, S. O., and J. W. Hopmans (1993), Optimization of hydraulic functions from transient outflow and soil-water pressure data, Soil Sci. Soc. Am. J., 57, 1167-1175.
68. Eching, S. O., J. W. Hopmans, and W. W. Wallender (1994), Estimation of in-situ unsaturated soil hydraulic functions from scaled cumulative drainage data, Water Resour. Res., 30, 2387-2394, doi:10.1029/94WR00756. (Pubitemid 286150)
69. Entekhabi, D., and M. Moghaddam (2007), Mapping recharge from space: Roadmap to meeting the grand challenge, Hydrogeol. J., 15, 105-116, doi:10.1007/s10040-006-0120-6. (Pubitemid 46196011)
70. Entekhabi, D., and I. Rodriguez-Iturbe (1994), Analytical framework for the characterization of the space-time variability of soil moisture, Adv. Water Resour., 17, 35-45, doi:10.1016/0309-1708 (94) 90022-1.
71. Entekhabi, D., H. Nakamura, and E. G. Njoku (1994), Solving the inverse problems for soil-moisture and temperature profiles by sequential assimilation of multifrequency remotely-sensed observations, IEEE Trans. Geosci. Remote Sens., 32, 438-448, doi:10.1109/36.295058.
72. Eppstein, M. J., and D. E. Dougherty (1998), Efficient three-dimensional data inversion: Soil characterization and moisture monitoring from crosswell ground-penetrating radar at a Vermont test site, Water Resour. Res., 34, 1889-1900, doi:10.1029/98WR00776.
73. Evensen, G. (1994), Sequential data assimilation with a nonlinear quasigeostrophic model using Monte Carlo methods to forecast error statistics, J. Geophys. Res., 99, 10,143-10,162, doi:10.1029/94JC00572.
74. Evett, S. R., and G. W. Parkin (2005), Advances in soil water content sensing: The continuing maturation of technology and theory, Vadose Zone J., 4, 986-991, doi:10.2136/vzj2005.0099.
75. Famiglietti, J. S., J. W. Rudnicki, and M. Rodell (1998), Variability in surface moisture content along a hillslope transect: Rattlesnake Hill, Texas, J. Hydrol., 210, 259-281, doi:10.1016/S0022-1694 (98) 00187-5.
76. Famiglietti, J. S., J. A. Devereaux, C. A. Laymon, T. Tsegaye, P. R. Houser, T. J. Jackson, S. T. Graham, M. Rodell, and P. J. van Oevelen (1999), Ground-based investigation of soil moisture variability within remote sensing footprints during the Southern Great Plains 1997 (SGP97) Hydrology Experiment, Water Resour. Res., 35, 1839-1851, doi:10.1029/1999WR900047. (Pubitemid 29243298)
77. Famiglietti, J. S., D. Ryu, A. A. Berg, M. Rodell, and T. J. Jackson (2008), Field observations of soil moisture variability across scales, Water Resour. Res., 44, W01423, doi:10.1029/2006WR005804. (Pubitemid 351304148)
78. Fares, A., and V. O. Polyakov (2006), Advances in crop water management using capacitive water sensors, in Advances in Agronomy, edited by D. Sparks, pp. 43-77, Academic, Amsterdam.
79. Feddes, R. A., M. Menenti, P. Kabat, and W. G. M. Bastiaanssen (1993), Is large-scale inverse modeling of unsaturated flow with areal average evaporation and surface soil-moisture as estimated from remote-sensing feasible, J. Hydrol., 143, 125-152, doi:10.1016/0022-1694 (93) 90092-N.
80. Fernandez-Galvez, J., L. P. Simmonds, and E. Barahona (2006), Estimating detailed soil water profile records from point measurements, Eur. J. Soil Sci., 57, 708-718.
81. Fields, A., R. Swain, R. Kennedy, W. Belisle, T. Coleman, and A. Sharma (2000), Laboratory and field measurements with a fiber-optic soil moisture sensor, Proc. SPIE, 4087, 1180-1187, doi:10.1117/12.406365.
82. Finsterle, S. (2005), Multiphase inverse modeling: Review and iTOUGH2 applications, Vadose Zone J., 3, 747-762.
83. Francois, C., A. Quesney, and C. Ottle (2003), Sequential assimilation of ERS-1 SAR data into a coupled land surface-hydrological model using an extended Kalman filter, J. Hydrometeorol., 4, 473-487, doi:10.1175/1525-7541 (2003) 4<473:SAOESD>2.0.CO;2.
84. Galantowicz, J. F. (1999), Tests of sequential data assimilation for retrieving profile soil moisture and temperature from observed L-band radiobrightness, IEEE Trans. Geosci. Remote Sens., 37, 1860-1870, doi:10.1109/36.774699.
85. Garrido, F., M. Ghodrati, and M. Chendorain (1999), Small-scale measurement of soil water content using a fiber optic sensor, Soil Sci. Soc. Am. J., 63, 1505-1512. (Pubitemid 30130381)
86. Georgakakos, K., and O. W. Baumer (1996), Measurement and utilization of on-site soil moisture data, J. Hydrol., 184, 131-152, doi:10.1016/0022-1694 (95) 02971-0.
87. Gillies, R. R., and T. N. Carlson (1995), Thermal remote-sensing of surface soil-water content with partial vegetation cover for incorporation into climate models, J. Appl. Meteorol., 34, 745-756, doi:10.1175/1520-0450 (1995) 034<0745:TRSOSS>2.0.CO;2.
88. Gomez-Plaza, A., J. Alvarez-Rogel, J. Albaladejo, and V. M. Castillo (2000), Spatial patterns and temporal stability of soil moisture across a range of scales in a semi-arid environment, Hydrol. Processes, 14, 1261-1277, doi:10.1002/(SICI) 1099-1085 (200005) 14:7<1261::AID-HYP40>3.0.CO;2-D.
89. Gouweleeuw, B. T., A. A. van de Griend, and M. Owe (1996), Estimation of "effective" soil hydraulic properties by top soil moisture and evaporation modeling applied to an arable site in central Spain, Water Resour. Res., 32, 1387-1392, doi:10.1029/96WR00197.
90. Goyal, V. C., P. K. Gupta, S. M. Seth, and V. N. Singh (1996), Estimation of temporal changes in soil moisture using resistivity method, Hydrol. Processes, 10, 1147-1154, doi:10.1002/(SICI) 1099-1085 (199609) 10:9< 1147::AID-HYP366>3.0.CO;2-S.
91. Grayson, R. B., and A. W. Western (1998), Towards areal estimation of soil water content from point measurements: Time and space stability of mean response, J. Hydrol., 207, 68-82, doi:10.1016/S0022-1694 (98) 00096-1.
92. Grayson, R. B., A. W. Western, F. H. S. Chiew, and G. Blöschl (1997), Preferred states in spatial soil moisture patterns: Local and nonlocal controls, Water Resour. Res., 33, 2897-2908, doi:10.1029/97WR02174.
93. Grayson, R. B., G. Blöschl, A. W. Western, and T. A. McMahon (2002), Advances in the use of observed spatial patterns of catchment hydrological response, Adv. Water Resour., 25, 1313-1334, doi:10.1016/S0309-1708 (02) 00060-X.
94. Green, S., and B. Clothier (1998), The root zone dynamics of water uptake by a mature apple tree, Plant Soil, 206, 61-77, doi:10.1023/A:1004368906698. (Pubitemid 29207880)
95. Hawley, M. E., T. J. Jackson, and R. H. McCuen (1983), Surface soilmoisture variation on small agricultural watersheds, J. Hydrol., 62, 179-200, doi:10.1016/0022-1694 (83) 90102-6.
96. Heathman, G. C., P. J. Starks, L. R. Ahuja, and T. J. Jackson (2003), Assimilation of surface soil moisture to estimate profile soil water content, J. Hydrol., 279, 1-17, doi:10.1016/S0022-1694 (03) 00088-X.
97. Henderson-Sellers, A. (1996), Soil moisture simulation: Achievements of the RICE and PILPS intercomparison workshop and future directions, Global Planet. Change, 13, 99-115, doi:10.1016/0921-8181 (95) 00035-6.
98. Herbst, M., and B. Diekkrüger (2003), Modelling the spatial variability of soil moisture in a micro-scale catchment and comparison with field data using geostatistics, Phys. Chem. Earth, 28, 239-245.
99. Herbst, M., W. Fialkiewicz, T. Chen, T. Putz, D. Thiery, C. Mouvet, G. Vachaud, and H. Vereecken (2005), Intercomparison of flow and transport models applied to vertical drainage in cropped lysimeters, Vadose Zone J., 4, 240-254, doi:10.2136/vzj2004.0070.
100. Hoeben, R., and P. A. Troch (2000), Assimilation of active microwave observation data for soil moisture profile estimation, Water Resour. Res., 36, 2805-2819, doi:10.1029/2000WR900100.
101. Hollenbeck, K. J., T. J. Schmugge, G. M. Hornberger, and J. R. Wang (1996), Identifying soil hydraulic heterogeneity by detection of relative change in passive microwave remote sensing observations, Water Resour. Res., 32, 139-148, doi:10.1029/95WR02916.
102. Houser, P. R., W. J. Shuttleworth, J. S. Famiglietti, H. V. Gupta, K. H. Syed, and D. C. Goodrich (1998), Integration of soil moisture remote sensing and hydrologic modeling using data assimilation, Water Resour. Res., 34, 3405-3420, doi:10.1029/1998WR900001.
103. Houtekamer, P. L., and H. L. Mitchell (1998), Data assimilation using an ensemble Kalman filter technique, Mon. Weather Rev., 126, 796-811, doi:10.1175/1520-0493 (1998) 126<0796:DAUAEK>2.0.CO;2.
104. Huisman, J. A., C. Sperl, W. Bouten, and J. M. Verstraten (2001), Soil water content measurements at different scales: Accuracy of time domain reflectometry and ground-penetrating radar, J. Hydrol., 245, 48-58, doi:10.1016/S0022-1694 (01) 00336-5.
105. Huisman, J. A., J. Snepvangers, W. Bouten, and G. B. M. Heuvelink (2002), Mapping spatial variation in surface soil water content: Comparison of ground-penetrating radar and time domain reflectometry, J. Hydrol., 269, 194-207, doi:10.1016/S0022-1694 (02) 00239-1. (Pubitemid 35464933)
106. Huisman, J. A., S. S. Hubbard, J. D. Redman, and A. P. Annan (2003), Measuring soil water content with ground penetrating radar: A review, Vadose Zone J., 2, 476-491.
107. Hupet, F., and A. Vanclooster (2005), Micro-variability of hydrological processes at the maize row scale: Implications for soil water content measurements and evapotranspiration estimates, J. Hydrol., 303, 247-270, doi:10.1016/j.jhydrol.2004.07.017. (Pubitemid 40307137)
108. Hupet, F., S. Lambot, M. Javaux, and M. Vanclooster (2002), On the identification of macroscopic root water uptake parameters from soil water content observations, Water Resour. Res., 38(12), 1300, doi:10.1029/ 2002WR001556.
109. Hupet, F., S. Lambot, R. A. Feddes, J. C. van Dam, and M. Vanclooster (2003), Estimation of root water uptake parameters by inverse modeling with soil water content data, Water Resour. Res., 39(11), 1312, doi:10.1029/2003WR002046.
110. Hurkmans, R., C. Paniconi, and P. A. Troch (2006), Numerical assessment of a dynamical relaxation data assimilation scheme for a catchment hydrological model, Hydrol. Processes, 20, 549-563, doi:10.1002/hyp. 5921.
111. Hymer, D. C., M. S. Moran, and T. O. Keefer (2000), Soil water evaluation using a hydrologic model and calibrated sensor network, Soil Sci. Soc. Am. J., 64, 319-326.
112. Hyndman, D. W., and S. M. Gorelick (1996), Estimating lithologic and transport properties in three dimensions using seismic and tracer data: The Kesterson aquifer, Water Resour. Res., 32, 2659-2670, doi:10.1029/96WR01269. (Pubitemid 26350856)
113. Ines, A. M. V., and B. P. Mohanty (2008), Near-surface soil moisture assimilation for quantifying effective soil hydraulic properties under different hydrocolimatic conditions, Vadose Zone J., 7, 39-52, doi:10.2136/vzj2007.0048. (Pubitemid 351362687)
114. Isham, V., D. R. Cox, I. Rodriguez-Iturbe, A. Porporato, and S. Manfreda (2005), Representation of space-time variability of soil moisture, Proc. R. Soc., Ser. A, 461, 4035-4055, doi:10.1098/rspa.2005.1568.
115. Jackson, T. J. (1993), Measuring surface soil-moisture using passive microwave remote-sensing, Hydrol. Processes, 7, 139-152, doi:10.1002/hyp. 3360070205.
116. Jackson, T. J. (2002), Remote sensing of soil moisture: Implications for groundwater recharge, Hydrogeol. J., 10, 40-51, doi:10.1007/s10040-001-0168-2. (Pubitemid 36238522)
117. Jackson, T. J., M. E. Hawley, and P. E. Oneill (1987), Preplanting soil-moisture using passive microwave sensors, Water Resour. Bull., 23, 11-19.
118. Jackson, T. J., et al. (1992), Multifrequency passive microwave observations of soil moisture in an arid rangeland environment, Int. J. Remote Sens., 13, 573-580, doi:10.1080/01431169208904059.
119. Jackson, T. J., D. M. Levine, A. J. Griffis, D. C. Goodrich, T. J. Schmugge, C. T. Swift, and P. E. Oneill (1993), Soil moisture and rainfall estimation over a semiarid environment with the ESTAR microwave radiometer, IEEE Trans. Geosci. Remote Sens., 31, 836-841, doi:10.1109/36.239906.
120. Jackson, T. J., D. M. Levine, C. T. Swift, T. J. Schmugge, and F. R. Schiebe (1995), Large-area mapping of soil moisture using the ESTAR passive microwave radiometer in Washita92, Remote Sens. Environ., 54, 27-37, doi:10.1016/0034-4257 (95) 00084-E.
121. Jackson, T. J., T. J. Schmugge, P. E. O'Neill, and M. B. Parlange (1998), Soil water infiltration observation with microwave radiometers, IEEE Trans. Geosci. Remote Sens., 36, 1376-1383, doi:10.1109/36.718838.
122. Jackson, T. J., D. M. Le Vine, A. Y. Hsu, A. Oldak, P. J. Starks, C. T. Swift, J. D. Isham, and M. Haken (1999), Soil moisture mapping at regional scales using microwave radiometry: The Southern Great Plains Hydrology Experiment, IEEE Trans. Geosci. Remote Sens., 37, 2136-2151, doi:10.1109/36.789610. (Pubitemid 30532642)
123. Jacobs, J. M., D. A. Myers, and B. M. Whitfield (2003), Improved rainfall/runoff estimates using remotely sensed soil moisture, J. Am. Water Resour. Assoc., 39, 313-324, doi:10.1111/j.1752-1688.2003.tb04386.x.
124. Jacobs, J. M., B. P. Mohanty, E. C. Hsu, and D. Miller (2004), SMEX02: Field scale variability, time stability and similarity of soil moisture, Remote Sens. Environ., 92, 436-446, doi:10.1016/j.rse.2004.02.017. (Pubitemid 39204627)
125. Jacques, D., B. Mohanty, A. Timmerman, and J. Feyen (2001), Study of time dependency of factors affecting the spatial distribution of soil water content in a field-plot, Phys. Chem. Earth, Part B, 26, 629-634, doi:10.1016/S1464-1909 (01) 00060-0.
126. Jawson, S. D., and J. D. Niemann (2007), Spatial patterns from EOF analysis of soil moisture at a large scale and their dependence on soil, land-use, and topographic properties, Adv. Water Resour., 30, 366-381, doi:10.1016/j.advwatres.2006.05.006. (Pubitemid 46131857)
127. Kabat, P., R. W. A. Hutjes, and R. A. Feddes (1997), The scaling characteristics of soil parameters: From plot scale heterogeneity to subgrid parameterization, J. Hydrol., 190, 363-396, doi:10.1016/S0022-1694 (96) 03134-4.
128. Kachanoski, R. G., and E. de Jong (1988), Scale dependence and the temporal persistence of spatial patterns of soil water storage, Water Resour. Res., 24, 85-91.
129. Kalman, R. E. (1960), A new approach to linear filtering and prediction problems, Trans. ASME, Ser. D, 82, 33-45.
130. Kamgar, A., J. W. Hopmans, W. W. Wallender, and O. Wendroth (1993), Plotsize and sample number for neutron probe measurements in smallfield trials, Soil Sci., 156, 213-224, doi:10.1097/00010694-199310000-00001.
131. Katra, I., D. G. Blumberg, H. Lavee, and P. Sarah (2006), A method for estimating the spatial distribution of soil moisture of arid microenvironments by close range thermal infrared imaging, Int. J. Remote Sens., 27, 2599-2611, doi:10.1080/01431160500522684. (Pubitemid 44219207)
132. Katra, I., D. G. Blumberg, H. Lavee, and P. Sarah (2007), Topsoil moisture patterns on arid hillsides-Micro-scale mapping by thermal infrared images, J. Hydrol., 334, 359-367, doi:10.1016/j.jhydrol.2006.10.023. (Pubitemid 46185394)
133. Katul, G. G., O. Wendroth, M. B. Parlange, C. E. Puente, M. V. Folegatti, and D. R. Nielsen (1993), Estimation of in situ hydraulic conductivity function from nonlinear filtering theory, Water Resour. Res., 29, 1063-1070, doi:10.1029/92WR02593. (Pubitemid 23383952)
134. Kerr, Y. H. (2007), Soil moisture from space: Where are we?, Hydrogeol. J., 15, 117-120, doi:10.1007/s10040-006-0095-3. (Pubitemid 46196012)
135. Kerr, Y. H., P. Waldteufel, J. P. Wigneron, J. M. Martinuzzi, J. Font, and M. Berger (2001), Soil moisture retrieval from space: The Soil Moisture and Ocean Salinity (SMOS) mission, IEEE Trans. Geosci. Remote Sens., 39, 1729-1735, doi:10.1109/36.942551. (Pubitemid 32933012)
136. Kool, J. B., J. C. Parker, and M. T. van Genuchten (1987), Parameter estimation for unsaturated flow and transport models-A review, J. Hydrol., 91, 255-293, doi:10.1016/0022-1694 (87) 90207-1.
137. Kostov, K. G., and T. J. Jackson (1993), Estimating profile soil moisture from surface layer measurements-A review, Proc. SPIE, 1941, 125-136.
138. Kowalsky, M. B., S. Finsterle, and Y. Rubin (2004), Estimating flow parameter distributions using ground-penetrating radar and hydrological measurements during transient flow in the vadose zone, Adv. Water Resour., 27, 583-599, doi:10.1016/j.advwatres.2004.03.003. (Pubitemid 38629839)
139. Kowalsky, M. B., S. Finsterle, J. Peterson, S. Hubbard, Y. Rubin, E. Majer, A. Ward, and G. Gee (2005), Estimation of field-scale soil hydraulic and dielectric parameters through joint inversion of GPR and hydrological data, Water Resour. Res., 41, W11425, doi:10.1029/2005WR004237. (Pubitemid 43041799)
140. Kumar, P. (1999), A multiple scale state-space model for characterizing subgrid scale variability of near-surface soil moisture, IEEE Trans. Geosci. Remote Sens., 37, 182-197, doi:10.1109/36.739153.
141. Kustas, W. P., and T. J. Jackson (1999), The impact on area-averaged heat fluxes from using remotely sensed data at different resolutions: A case study with Washita'92 data, Water Resour. Res., 35, 1539-1550, doi:10.1029/ 1998WR900122. (Pubitemid 29207987)
142. Laio, F., A. Porporato, L. Ridolfi, and I. Rodriguez-Iturbe (2002), On the seasonal dynamics of mean soil moisture, J. Geophys. Res., 107 (D), 15, doi:10.1029/2001JD001252. (Pubitemid 43211863)
143. Lambot, S., and A. Gorriti (2007), Special issue on ground-penetrating radar-Foreword, Near Surf. Geophys., 5, 3-4.
144. Lambot, S., M. Javaux, F. Hupet, and M. Vanclooster (2002), A global multilevel coordinate search procedure for estimating the unsaturated soil hydraulic properties, Water Resour. Res., 38(11), 1224, doi:10.1029/ 2001WR001224.
145. Lambot, S., F. Hupet, M. Javaux, and M. Vanclooster (2004), Laboratory evaluation of a hydrodynamic inverse modeling method based on water content data, Water Resour. Res., 40, W03506, doi:10.1029/2003WR002641.
146. Lambot, S., E. C. Slob, M. Vanclooster, and H. Vereecken (2006a), Closed loop GPR data inversion for soil hydraulic and electric property determination, Geophys. Res. Lett., 33, L21405, doi:10.1029/2006GL027906. (Pubitemid 46747132)
147. Lambot, S., L. Weihermuller, J. A. Huisman, H. Vereecken, M. Vanclooster, and E. C. Slob (2006b), Analysis of air-launched ground-penetrating radar techniques to measure the soil surface water content, Water Resour. Res., 42, W11403, doi:10.1029/2006WR005097. (Pubitemid 46134875)
148. Laymon, C. A., et al. (1999), Huntsville'96: An experiment in groundbased microwave remote sensing of soil moisture, Int. J. Remote Sens., 20, 823-828, doi:10.1080/014311699213244.
149. Li, J., and S. Islam (1999), On the estimation of soil moisture profile and surface fluxes partitioning from sequential assimilation of surface layer soil moisture, J. Hydrol., 220, 86-103, doi:10.1016/S0022-1694 (99) 00066-9.
150. Li, Y., R. Wallach, and Y. Cohen (2002), The role of soil hydraulic conductivity on the spatial and temporal variation of root water uptake in drip-irrigated corn, Plant Soil, 243, 131-142, doi:10.1023/A:1019911908635. (Pubitemid 35028819)
151. Lin, H. (2006), Temporal stability of soil moisture spatial pattern and subsurface preferential flow pathways in the shale hills catchment, Vadose Zone J., 5, 317-340, doi:10.2136/vzj2005.0058. (Pubitemid 47254039)
152. Lunt, I. A., S. S. Hubbard, and Y. Rubin (2005), Soil moisture content estimation using ground-penetrating radar reflection data, J. Hydrol., 307, 254-269, doi:10.1016/j.jhydrol.2004.10.014. (Pubitemid 40743130)
153. Mahmood, R. (1996), Scale issues in soil moisture modelling: Problems and prospects, Prog. Phys. Geogr., 20, 273-291, doi:10.1177/030913339602000302.
154. Manfreda, S., and I. Rodríguez-Iturbe (2006), On the spatial and temporal sampling of soil moisture fields, Water Resour. Res., 42, W05409, doi:10.1029/2005WR004548. (Pubitemid 43955909)
155. Margulis, S. A., D. McLaughlin, D. Entekhabi, and S. Dunne (2002), Land data assimilation and estimation of soil moisture using measurements from the Southern Great Plains 1997 Field Experiment, Water Resour. Res., 38(12), 1299, doi:10.1029/2001WR001114.
156. Martinez-Fernandez, J., and A. Ceballos (2003), Temporal stability of soil moisture in a large-field experiment in Spain, Soil Sci. Soc. Am. J., 67, 1647-1656.
157. Mattikalli, N. M., E. T. Engman, T. J. Jackson, and L. R. Ahuja (1998a), Microwave remote sensing of temporal variations of brightness temperature and near-surface soil water content during a watershed-scale field experiment, and its application to the estimation of soil physical properties, Water Resour. Res., 34, 2289-2299, doi:10.1029/98WR00553. (Pubitemid 28407898)
158. Mattikalli, N. M., E. T. Engman, L. R. Ahuja, and T. J. Jackson (1998b), Microwave remote sensing of soil moisture for estimation of profile soil property, Int. J. Remote Sens., 19, 1751-1767, doi:10.1080/014311698215234.
159. McLaughlin, D. B. (1978), Potential applications of Kalman filtering concepts to groundwater basin management, in Applications of Kalman Filter to Hydrology, Hydraulics, and Water Resources, edited by C.-L. Chiu, pp. 635-655, Univ. of Pittsburgh, Pittsburgh, Pa.
160. Merlin, O., A. Chehbouni, G. Boulet, and Y. Kerr (2006), Assimilation of disaggregated microwave soil moisture into a hydrologic model using coarse-scale meteorological data, J. Hydrometeorol., 7, 1308-1322, doi:10.1175/JHM552.1. (Pubitemid 46111238)
161. Mertens, J., H. Madsen, L. Feyen, D. Jacques, and J. Feyen (2004), Including prior information in the estimation of effective soil parameters in unsaturated zone modelling, J. Hydrol., 294, 251-269, doi:10.1016/j.jhydrol. 2004.02.011. (Pubitemid 38791098)
162. Mertens, J., H. Madsen, M. Kristensen, D. Jacques, and J. Feyen (2005), Sensitivity of soil parameters in unsaturated zone modelling and the relation between effective, laboratory and in situ estimates, Hydrol. Processes, 19, 1611-1633, doi:10.1002/hyp. 5591.
163. Mertens, J., R. Stenger, and G. F. Barkle (2006), Multiobjective inverse modeling for soil parameter estimation and model verification, Vadose Zone J., 5, 917-933, doi:10.2136/vzj2005.0117. (Pubitemid 47253973)
164. Merz, B., and E. J. Plate (1997), An analysis of the effects of spatial variability of soil and soil moisture on runoff, Water Resour. Res., 33, 2909-2922, doi:10.1029/97WR02204.
165. Michot, D., Y. Benderitter, A. Dorigny, B. Nicoullaud, D. King, and A. Tabbagh (2003), Spatial and temporal monitoring of soil water content with an irrigated corn crop cover using surface electrical resistivity tomography, Water Resour. Res., 39(5), 1138, doi:10.1029/2002WR001581.
166. Mohanty, B. P., and T. H. Skaggs (2001), Spatio-temporal evolution and time-stable characteristics of soil moisture within remote sensing footprints with varying soil, slope, and vegetation, Adv. Water Resour., 24, 1051-1067, doi:10.1016/S0309-1708 (01) 00034-3.
167. Mohanty, B. P., T. H. Skaggs, and J. S. Famiglietti (2000), Analysis and mapping of field-scale soil moisture variability using high-resolution, ground-based data during the Southern Great Plains 1997 (SGP97) Hydrology Experiment, Water Resour. Res., 36, 1023-1031, doi:10.1029/1999WR900360. (Pubitemid 30181386)
168. Mohanty, B. P., P. J. Shouse, D. A. Miller, and M. T. van Genuchten (2002), Soil property database: Southern Great Plains 1997 Hydrology Experiment, Water Resour. Res., 38(5), 1047, doi:10.1029/2000WR000076.
169. Montaldo, N., and J. D. Albertson (2001), On the use of the force-restore SVAT model formulation for stratified soils, J. Hydrometeorol., 2, 571-578, doi:10.1175/1525-7541 (2001) 002<0571:OTUOTF>2.0.CO;2.
170. Montaldo, N., and J. D. Albertson (2003a), Multi-scale assimilation of surface soil moisture data for robust root zone moisture predictions, Adv. Water Resour., 26, 33-44, doi:10.1016/S0309-1708 (02) 00103-3.
171. Montaldo, N., and J. D. Albertson (2003b), Temporal dynamics of soil moisture variability: 2. Implications for land surface models, Water Resour. Res., 39(10), 1275, doi:10.1029/2002WR001618.
172. Montaldo, N., J. D. Albertson, M. Mancini, and G. Kiely (2001), Robust simulation of root zone soil moisture with assimilation of surface soil moisture data, Water Resour. Res., 37, 2889-2900, doi:10.1029/2000WR000209. (Pubitemid 34108251)
173. Mori, Y., J. W. Hopmans, A. P. Mortensen, and G. J. Kluitenberg (2005), Estimation of vadose zone water flux from multi-functional heat pulse probe measurements, Soil Sci. Soc. Am. J., 69, 599-606, doi:10.2136/sssaj2004.0174. (Pubitemid 40660518)
174. Mortensen, A. P., J. W. Hopmans, Y. Mori, and J. Simunek (2006), Multifunctional heat pulse probe measurements of coupled vadose zone flow and transport, Adv. Water Resour., 29, 250-267, doi:10.1016/j.advwatres.2005.03.017. (Pubitemid 43019345)
175. Musters, P. A. D., and W. Bouten (1999), Assessing rooting depths of an Austrian pine stand by inverse modeling soil water content maps, Water Resour. Res., 35, 3041-3048, doi:10.1029/1999WR900173. (Pubitemid 29461968)
176. Musters, P. A. D., and W. Bouten (2000), A method for identifying optimum strategies of measuring soil water contents for calibrating a root water uptake model, J. Hydrol., 227, 273-286, doi:10.1016/S0022-1694 (99) 00187-0.
177. Musters, P. A. D., W. Bouten, and J. M. Verstraten (2000), Potentials and limitations of modelling vertical distributions of root water uptake of an Austrian pine forest on a sandy soil, Hydrol. Processes, 14, 103-115, doi:10.1002/(SICI) 1099-1085 (200001) 14:1<103::AID-HYP913>3.0.CO;2-5.
178. Narayan, U., V. Lakshmi, and E. G. Njoku (2004), Retrieval of soil moisture from passive and active L/S band sensor (PALS) observations during the Soil Moisture Experiment in 2002 (SMEX02), Remote Sens. Environ., 92, 483-496, doi:10.1016/j.rse.2004.05.018. (Pubitemid 39204631)
179. Nieber, J. L., and M. F. Walter (1981), Two-dimensional soil-moisture flow in a sloping rectangular region: Experimental and numerical studies, Water Resour. Res., 17, 1722-1730, doi:10.1029/WR017i006p01722.
180. Niemann, K. O., and M. C. R. Edgell (1993), Preliminary analysis of spatial and temporal distribution of soil moisture on a deforested slope, Phys. Geogr., 14, 449-464.
181. Ni-Meister, W., P. R. Houser, and J. P. Walker (2006), Soil moisture initialization for climate prediction: Assimilation of scanning multifrequency microwave radiometer soil moisture data into a land surface model, J. Geophys. Res., 111, D20102, doi:10.1029/2006JD007190. (Pubitemid 44941262)
182. Nutzmann, G., M. Thiele, S. Maciejewski, and K. Joswig (1998), Inverse modelling techniques for determining hydraulic properties of coarse-textured porous media by transient outflow methods, Adv. Water Resour., 22, 273-284, doi:10.1016/S0309-1708 (98) 00009-8.
183. Oldak, A., T. J. Jackson, and Y. Pachepsky (2002), Using GIS in passive microwave soil moisture mapping and geostatistical analysis, Int. J. Geogr. Inf. Sci., 16, 681-698, doi:10.1080/13658810210149407.
184. Or, D., and R. J. Hanks (1992), Spatial and temporal soil water estimation considering soil variability and evapotranspiration uncertainty, Water Resour. Res., 28, 803-814, doi:10.1029/91WR02585.
185. Owe, M., E. B. Jones, and T. J. Schmugge (1982), Soil-moisture variation patterns observed in Hand County, South Dakota, Water Resour. Bull., 18, 949-954.
186. Pachepsky, Y. A., A. K. Guber, and D. Jacques (2005), Temporal persistence in vertical distributions of soil moisture contents, Soil Sci. Soc. Am. J., 69, 347-352.
187. Pan, L. H., and L. S. Wu (1998), A hybrid global optimization method for inverse estimation of hydraulic parameters: Annealing-simplex method, Water Resour. Res., 34, 2261-2269, doi:10.1029/98WR01672. (Pubitemid 28407895)
188. Pan, M., and E. F. Wood (2006), Data assimilation for estimating the terrestrial water budget using a constrained ensemble Kalman filter, J. Hydrometeorol., 7, 534-547, doi:10.1175/JHM495.1. (Pubitemid 44070419)
189. Paniconi, C., M. Marrocu, M. Putti, and M. Verbunt (2003), Newtonian nudging for a Richards equation-based distributed hydrological model, Adv. Water Resour., 26, 161-178, doi:10.1016/S0309-1708 (02) 00099-4.
190. Parada, L. M., and X. Liang (2004), Optimal multiscale Kalman filter for assimilation of near-surface soil moisture into land surface models, J. Geophys. Res., 109, D24109, doi:10.1029/2004JD004745. (Pubitemid 40335193)
191. Parajka, J., V. Naeimi, G. Blöschl, W. Wagner, R. Merz, and K. Scipal (2006), Assimilating scatterometer soil moisture data into conceptual hydrologic models at the regional scale, Hydrol. Earth Syst. Sci., 10, 353-368.
192. Pariente, S. (2002), Spatial patterns of soil moisture as affected by shrubs, in different climatic conditions, Environ. Monit. Assess., 73, 237-251, doi:10.1023/A:1013119405441. (Pubitemid 34134149)
193. Pauwels, V. R. N., R. Hoeben, N. E. C. Verhoest, and F. P. de Troch (2001), The importance of the spatial patterns of remotely sensed soil moisture in the improvement of discharge predictions for small-scale basins through data assimilation, J. Hydrol., 251, 88-102, doi:10.1016/S0022-1694 (01) 00440-1.
194. Pauwels, V. R. N., R. Hoeben, N. E. C. Verhoest, F. P. de Troch, and P. A. Troech (2002), Improvement of TOPLATS-based discharge predictions through assimilation of ERS-based remotely sensed soil moisture values, Hydrol. Processes, 16, 995-1013, doi:10.1002/hyp. 315.
195. Pauwels, V. R. N., N. E. C. Verhoest, G. J. M. de Lannoy, V. Guissard, C. Lucau, and P. Defourny (2007), Optimization of a coupled hydrology-crop growth model through the assimilation of observed soil moisture and leaf area index values using an ensemble Kalman filter, Water Resour. Res., 43, W04421, doi:10.1029/2006WR004942. (Pubitemid 46799528)
196. Perry, M. A., and J. D. Niemann (2007), Analysis and estimation of soil moisture at the catchment scale using EOFs, J. Hydrol., 334, 388-404, doi:10.1016/j.jhydrol.2006.10.014. (Pubitemid 46185396)
197. Pratt, D. A., and C. D. Ellyett (1979), Thermal inertia approach to mapping of soil moisture and geology, Remote Sens. Environ., 8, 151-168, doi:10.1016/0034-4257 (79) 90014-2.
198. Prevot, L., R. Bernard, O. Taconet, D. Vidalmadjar, and J. L. Thony (1984), Evaporation from a bare soil evaluated using a soil-water transfer model and remotely sensed surface soil moisture data, Water Resour. Res., 20, 311-316, doi:10.1029/WR020i002p00311.
199. Price, J. C. (1980), The potential of remotely sensed thermal infrared data to infer surface soil moisture and evaporation, Water Resour. Res., 16, 787-795, doi:10.1029/WR016i004p00787.
200. Reggiani, P., M. Sivapalan, and S. M. Hassanizadeh (2000), Conservation equations governing hillslope responses: Exploring the physical basis of water balance, Water Resour. Res., 36, 1845-1863, doi:10.1029/2000WR900066.
201. Reichle, R. (2008), Data assimilation methods in the Earth sciences, Adv. Water Resour., in press.
202. Reichle, R. H., D. B. McLaughlin, and D. Entekhabi (2001), Variational data assimilation of microwave radiobrightness observations for land surface hydrology applications, IEEE Trans. Geosci. Remote Sens., 39, 1708-1718, doi:10.1109/36.942549. (Pubitemid 32933010)
203. Reichle, R. H., J. P. Walker, R. D. Koster, and P. R. Houser (2002a), Extended versus ensemble Kalman filtering for land data assimilation, J. Hydrometeorol., 3, 728-740, doi:10.1175/1525-7541 (2002) 003< 0728:EVEKFF>2.0.CO;2.
204. Reichle, R. H., D. B. McLaughlin, and D. Entekhabi (2002a), Hydrologic data assimilation with the ensemble Kalman filter, Mon. Weather Rev., 130, 103-114, doi:10.1175/1520-0493 (2002) 130<0103:HDAWTE> 2.0.CO;2.
205. Reid, I. (1973), The influence of slope orientation upon the soil moisture regime and its hydrogeomorphologcial significance, J. Hydrol., 19, 309-321, doi:10.1016/0022-1694 (73) 90105-4.
206. Ren, T., G. J. Kluitenberg, and R. Horton (2000), Determining soil water flux and pore water velocity by a heat pulse technique, Soil Sci. Soc. Am. J., 64, 552-560.
207. Retter, M., P. Kienzler, and P. F. Germann (2006), Vectors of subsurface stormflow in a layered hillslope during runoff initiation, Hydrol. Earth Syst. Sci., 10, 309-320.
208. Ridolfi, L., P. D'Odorico, A. Porporato, and I. Rodriguez-Iturbe (2003), Stochastic soil moisture dynamics along a hillslope, J. Hydrol., 272, 264-275, doi:10.1016/S0022-1694 (02) 00270-6.
209. Ritter, A., F. Hupet, R. Munoz-Carpena, S. Lambot, and M. Vanclooster (2003), Using inverse methods for estimating soil hydraulic properties from field data as an alternative to direct methods, Agric. Water Manage., 59, 77-96, doi:10.1016/S0378-3774 (02) 00160-9.
210. Robinson, D. A., S. B. Jones, J. A. Wraith, D. Or, and S. P. Friedman (2003), A review of advances in dielectric and electrical conductivity measurement in soils using time domain reflectometry, Vadose Zone J., 2, 444-475.
211. Robinson, D. A., C. S. Campbell, J. W. Hopmans, B. K. Hornbuckle, S. B. Jones, R. Knight, F. Ogden, J. Selker, and O. Wendroth (2008), Soil moisture measurements for ecological and hydrological watershed scale observatories: A review, Vadose Zone J., 7, 358-389, doi:10.2136/vzj2007.0143. (Pubitemid 351362719)
212. Robock, A., K. Y. Vinnikov, G. Srinivasan, J. K. Entin, S. E. Hollinger, N. A. Speranskaya, S. X. Liu, and A. Namkhai (2000), The Global Soil Moisture Data Bank, Bull. Am. Meteorol. Soc., 81, 1281-1299, doi:10.1175/1520-0477 (2000) 081<1281:TGSMDB>2.3. CO;2.
213. Rodriguez-Iturbe, I., G. K. Vogel, R. Rigon, D. Entekhabi, F. Castelli, and A. Rinaldo (1995), On the spatial organization of soil moisture fields, Geophys. Res. Lett., 22, 2757-2760, doi:10.1029/95GL02779. (Pubitemid 26444248)
214. Rodriguez-Iturbe, I., A. Porporato, L. Ridolfi, V. Isham, and D. R. Cox (1999), Probabilistic modelling of water balance at a point: The role of climate, soil and vegetation, Proc. R. Soc. London, Ser. A, 455, 3789-3805.
215. Rodriguez-Iturbe, I., V. Isham, D. R. Cox, S. Manfreda, and A. Porporato (2006), Space-time modeling of soil moisture: Stochastic rainfall forcing with heterogeneous vegetation, Water Resour. Res., 42, W06D05, doi:10.1029/ 2005WR004497. (Pubitemid 44156586)
216. Ross, P. J. (1993), A method of deriving soil hydraulic properties from field water contents for application in water-balance studies, J. Hydrol., 144, 143-153, doi:10.1016/0022-1694 (93) 90169-A.
217. Rubin, Y., and S. S. Hubbard (2005), Hydrogeophysics, Water Sci. Technol. Libr., vol. 50, 523 pp., Springer, Dordrecht, Netherlands.
218. Rucker, D. F., and T. P. A. Ferré (2004), Parameter estimation for soil hydraulic properties using zero-offset borehole radar: Analytical method, Soil Sci. Soc. Am. J., 68, 1560-1567.
219. Rushton, K. R., V. H. M. Eilers, and R. C. Carter (2006), Improved soil moisture balance methodology for recharge estimation, J. Hydrol., 318, 379-399, doi:10.1016/j.jhydrol.2005.06.022. (Pubitemid 43120807)
220. Ryu, D., and J. S. Famiglietti (2005), Characterization of footprint-scale surface soil moisture variability using Gaussian and beta distribution functions during the Southern Great Plains 1997 (SGP97) hydrology experiment, Water Resour. Res., 41, W12433, doi:10.1029/2004WR003835. (Pubitemid 43153738)
221. Sabater, J. M., L. Jarlan, J. C. Calvet, F. Bouyssel, and P. de Rosnay (2007), From near-surface to root-zone soil moisture using different assimilation techniques, J. Hydrometeorol., 8, 194-206, doi:10.1175/JHM571.1. (Pubitemid 46739314)
222. Samouelian, A., I. Cousin, A. Tabbagh, A. Bruand, and G. Richard (2005), Electrical resistivity survey in soil science: A review, Soil Tillage Res., 83, 173-193, doi:10.1016/j.still.2004.10.004. (Pubitemid 41009182)
223. Satalino, G., F. Mattia, M. W. J. Davidson, T. Le Toan, G. Pasquariello, and M. Borgeaud (2002), On current limits of soil moisture retrieval from ERS-SAR data, IEEE Trans. Geosci. Remote Sens., 40, 2438-2447, doi:10.1109/TGRS.2002.803790.
224. Schmugge, T. (1998), Applications of passive microwave observations of surface soil moisture, J. Hydrol., 212-213, 188-197, doi:10.1016/S0022-1694 (98) 00209-1. (Pubitemid 29020065)
225. Schmugge, T., T. J. Jackson, W. P. Kustas, and J. R. Wang (1992), Passive microwave remote sensing of soil moisture-Results from Hapex, Fife and Monsoon-90, ISPRS J. Photogramm. Remote Sens., 47, 127-143, doi:10.1016/0924- 2716 (92) 90029-9.
226. Schmugge, T. J., W. P. Kustas, J. C. Ritchie, T. J. Jackson, and A. Rango (2002), Remote sensing in hydrology, Adv. Water Resour., 25, 1367-1385, doi:10.1016/S0309-1708 (02) 00065-9.
227. Schoups, G., J. W. Hopmans, C. A. Young, J. A. Vrugt, and W. W. Wallender (2005a), Multi-criteria optimization of a regional spatially-distributed subsurface water flow model, J. Hydrol., 311, 20-48, doi:10.1016/j.jhydrol.2005. 01.001. (Pubitemid 41261597)
228. Schoups, G., J. W. Hopmans, C. A. Young, J. A. Vrugt, W. W. Wallender, K. K. Tanji, and S. Panday (2005b), Sustainability of irrigated agriculture in the San Joaquin Valley, California, Proc. Natl. Acad. Sci. U. S. A., 102, 15,352-15,356, doi:10.1073/pnas.0507723102. (Pubitemid 41528060)
229. Scipal, K., C. Scheffler, and W. Wagner (2005), Soil moisture-runoff relation at the catchment scale as observed with coarse resolution microwave remote sensing, Hydrol. Earth Syst. Sci., 9, 173-183.
230. Scott, R. L., W. J. Shuttleworth, T. O. Keefer, and A. W. Warrick (2000), Modeling multiyear observations of soil moisture recharge in the semiarid American Southwest, Wate r Resour. Res., 36, 2233-2247, doi:10.1029/ 2000WR900116.
231. Sellers, P. J., F. G. Hall, G. Asrar, D. E. Strebel, and R. E. Murphy (1992), An overview of the 1st International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE), J. Geophys. Res., 97, 18,345-18,371.
232. Sellers, P. J., M. D. Heiser, F. G. Hall, S. J. Goetz, D. E. Strebel, S. B. Verma, R. L. Desjardins, P. M. Schuepp, and J. I. MacPherson (1995), Effects of spatial variability in topography, vegetation cover and soil moisture on area-averaged surface fluxes: A case study using the FIFE 1989 data, J. Geophys. Res., 100, 25,607-25,629, doi:10.1029/95JD02205.
233. Serbin, G., and D. Or (2004), Ground-penetrating radar measurement of soil water content dynamics using a suspended horn antenna, IEEE Trans. Geosci. Remote Sens., 42, 1695-1705, doi:10.1109/TGRS.2004.831693.
234. Serbin, G., and D. Or (2005), Ground-penetrating radar measurement of crop and surface water content dynamics, Remote Sens. Environ., 96, 119-134, doi:10.1016/j.rse.2005.01.018. (Pubitemid 40623231)
235. Settin, T., G. Botter, I. Rodriguez-Iturbe, and A. Rinaldo (2007), Numerical studies on soil moisture distributions in heterogeneous catchments, Water Resour. Res., 43, W05425, doi:10.1029/2006WR005737. (Pubitemid 46998226)
236. Sheets, K. R., and J. M. H. Hendrickx (1995), Noninvasive soil-water content measurement using electromagnetic induction, Water Resour. Res., 31, 2401-2409, doi:10.1029/95WR01949. (Pubitemid 26442779)
237. Si, B. C., and R. G. Kachanoski (2000), Estimating soil hydraulic properties during constant flux infiltration: Inverse procedures, Soil Sci. Soc. Am. J., 64, 439-449.
238. Simunek, J., and J. W. Hopmans (2002), Parameter optimization and nonlinear fitting, in Methods of Soil Analyses, edited by J. H. Dane and G. C. Topp, pp. 139-158, Soil. Sci. Soc. of Am., Madison, Wis.
239. Simunek, J., O. Wendroth, and M. T. van Genuchten (1998), Parameter estimation analysis of the evaporation method for determining soil hydraulic properties, Soil Sci. Soc. Am. J., 62, 894-905. (Pubitemid 28403919)
240. Sisson, J. B., and M. T. van Genuchten (1991), An improved analysis of gravity-drainage experiments for estimating the unsaturated soil hydraulic properties, Water Resour. Res., 27, 569-575, doi:10.1029/91WR00184.
241. Sposito, G. (1998), Scale Dependence and Scale Invariance in Hydrology, 423 pp., Cambridge Univ. Press, Cambridge, U. K.
242. Starks, P. J., G. C. Heathman, T. J. Jackson, and M. H. Cosh (2006), Temporal stability of soil moisture profile, J. Hydrol., 324, 400-411, doi:10.1016/j.jhydrol.2005.09.024. (Pubitemid 43729371)
243. Starr, G. C. (2005), Assessing temporal stability and spatial variability of soil water patterns with implications for precision water management, Agric. Water Manage., 72, 223-243, doi:10.1016/j.agwat.2004.09.020. (Pubitemid 40199640)
244. Sugiura, R., N. Noguchi, and K. Ishii (2007), Correction of low-altitude thermal images applied to estimating soil water status, Biosyst. Eng., 96, 301-313, doi:10.1016/j.biosystemseng.2006.11.006. (Pubitemid 46241048)
245. Takeshita, Y. (1999), Parameter estimation of unsaturated soil hydraulic properties from transient outflow experiments using genetic algorithms, paper presented at Characterization and Measurement of the Hydraulic Properties of Unsaturated Porous Media, U. S. Salinity Lab., Agric. Res. Serv., U. S. Dep. of Agric., Riverside, Calif., 22-24 Oct.
246. Teuling, A. J., R. Uijlenhoet, F. Hupet, E. E. van Loon, and P. A. Troch (2006), Estimating spatial mean root-zone soil moisture from point-scale observations, Hydrol. Earth Syst. Sci., 10, 755-767. (Pubitemid 44600395)
247. Teuling, A. J., F. Hupet, R. Uijlenhoet, and P. A. Troch (2007), Climate variability effects on spatial soil moisture dynamics, Geophys. Res. Lett., 34, L06406, doi:10.1029/2006GL029080. (Pubitemid 46865309)
248. Thierfelder, T. K., R. B. Grayson, D. von Rosen, and A. W. Western (2003), Inferring the location of catchment characteristic soil moisture monitoring sites. Covariance structures in the temporal domain, J. Hydrol., 280, 13-32, doi:10.1016/S0022-1694 (03) 00077-5.
249. Topp, G. C. (2003), State of the art of measuring soil water content, Hydrol. Processes, 17, 2993-2996, doi:10.1002/hyp. 5148.
250. Tromp-van Meerveld, H. J., and J. J. McDonnell (2006), On the interrelations between topography, soil depth, soil moisture, transpiration rates and species distribution at the hillslope scale, Adv. Water Resour., 29, 293-310, doi:10.1016/j.advwatres.2005.02.016. (Pubitemid 43019348)
251. Ulaby, F. T., P. C. Dubois, and J. van Zyl (1996), Radar mapping of surface soil moisture, J. Hydrol., 184, 57-84, doi:10.1016/0022-1694 (95) 02968-0.
252. Vachaud, G., A. P. Desilans, P. Balabanis, and M. Vauclin (1985), Temporal stability of spatially measured soil-water probability density function, Soil Sci. Soc. Am. J., 49, 822-828.
253. Valente, A., R. Morais, A. Tuli, J. W. Hopmans, and G. J. Kluitenberg (2006), Multi-functional probe for small-scale simultaneous measurements of soil thermal properties, water content, and electrical conductivity, Sensors Actuators A, 132, 70-77, doi:10.1016/j.sna.2006.05.010. (Pubitemid 44764977)
254. van Dam, J. C., J. N. M. Stricker, and P. Droogers (1992), Inverse method for determining soil hydraulic functions from one-step outflow experiments, Soil Sci. Soc. Am. J., 56, 1042-1050.
255. van Groenigen, J. W. (2000), The influence of variogram parameters on optimal sampling schemes for mapping by kriging, Geoderma, 97, 223-236.
256. Vereecken, H., M. Vanclooster, M. Swerts, and J. Diels (1991), Simulating water and nitrogen behaviour in soils cropped with winter wheat, Nutrient Cycling Agroecosyst., 27, 233-243, doi:10.1007/BF01051130.
257. Vereecken, H., R. Kaiser, M. Dust, and T. Putz (1997), Evaluations of the multistep outflow method for the determination of unsaturated hydraulic properties of soils, Soil Sci., 162, 618-631, doi:10.1097/00010694-199709000- 00003.
258. Vereecken, H., S. Hubbard, A. Binley, and T. Ferré (2004), Hydrogeophysics: An introduction from the guest editors, Vadose Zone J., 3, 1060-1062.
259. Vereecken, H., A. Binley, G. Cassiani, A. Revil, and K. Titov (2006), Applied Hydrogeophysics, NATO Sci Ser. Ser. 4, vol. 71, 383 pp., Springer, Dordrecht, Netherlands.
260. Vereecken, H., R. Kasteel, J. Vanderborght, and T. Harter (2007a), Upscaling hydraulic properties and soil water flow processes in heterogeneous soils: A review, Vadose Zone J., 6, 1-28, doi:10.2136/vzj2006.0055. (Pubitemid 47252325)
261. Vereecken, H., T. Kamai, T. Harter, R. Kasteel, J. Hopmans, and J. Vanderborght (2007b), Explaining soil moisture variability as a function of mean soil moisture: A stochastic unsaturated flow perspective, Geophys. Res. Lett., 34, L22402, doi:10.1029/2007GL031813. (Pubitemid 351222802)
262. Verhoest, N. E. C., P. A. Troch, C. Paniconi, and F. P. de Troch (1998), Mapping basin scale variable source areas from multitemporal remotely sensed observations of soil moisture behavior, Water Resour. Res., 34, 3235-3244, doi:10.1029/98WR02046.
263. Verhoest, N. E. C., B. de Baets, and H. Vernieuwe (2007), A Takagi-Sugeno fuzzy rule-based model for soil moisture retrieval from SAR under soil roughness uncertainty, IEEE Trans. Geosci. Remote Sens., 45, 1351-1360, doi:10.1109/TGRS.2007.894930. (Pubitemid 46652336)
264. Verstraeten, W. W., F. Veroustraete, C. J. van der Sande, I. Grootaers, and J. Feyen (2006), Soil moisture retrieval using thermal inertia, determined with visible and thermal spaceborne data, validated for European forests, Remote Sens. Environ., 101, 299-314, doi:10.1016/j.rse. 2005.12.016.
265. Visser, A., R. Stuurman, and M. F. P. Bierkens (2006), Real-time forecasting of water table depth and soil moisture profiles, Adv. Water Resour., 29, 692-706, doi:10.1016/j.advwatres.2005.07.011.
266. Vogeler, I., S. R. Green, D. R. Scotter, and B. E. Clothier (2001), Measuring and modelling the transport and root uptake of chemicals in the unsaturated zone, Plant Soil, 231, 161-174, doi:10.1023/A:1010337132309. (Pubitemid 32595957)
267. Vrugt, J. A., and W. Bouten (2002), Validity of first-order approximations to describe parameter uncertainty in soil hydrologic models, Soil Sci. Soc. Am. J., 66, 1740-1751.
268. Vrugt, J. A., and J. H. Dane (2005), Inverse modeling of soil hydraulic properties, in Encyclopedia of Hydrological Sciences, edited by M. G. Anderson, pp. 1103-1120, John Wiley, Chichester, U. K.
269. Vrugt, J. A., and B. A. Robinson (2007), Improved evolutionary optimization from genetically adaptive multimethod search, Proc. Natl. Acad. Sci. U. S. A., 104, 708-711, doi:10.1073/pnas.0610471104. (Pubitemid 46154674)
270. Vrugt, J. A., W. Bouten, and A. H. Weerts (2001a), Information content of data for identifying soil hydraulic parameters from outflow experiments, Soil Sci. Soc. Am. J., 65, 19-27.
271. Vrugt, J. A., J. W. Hopmans, and J. Simunek (2001b), Calibration of a twodimensional root water uptake model, Soil Sci. Soc. Am. J., 65, 1027-1037.
272. Vrugt, J. A., M. T. van Wijk, J. W. Hopmans, and J. Simunek (2001c), One-, two-, and three-dimensional root water uptake functions for transient modeling, Water Resour. Res., 37, 2457-2470, doi:10.1029/2000WR000027. (Pubitemid 32908196)
273. Vrugt, J. A., H. V. Gupta, L. A. Bastidas, W. Bouten, and S. Sorooshian (2003), Effective and efficient algorithm for multiobjective optimization of hydrologic models, Water Resour. Res., 39(8), 1214, doi:10.1029/2002WR001746.
274. Vrugt, J. A., G. Schoups, J. W. Hopmans, C. Young, W. W. Wallender, T. Harter, and W. Bouten (2004), Inverse modeling of large-scale spatially distributed vadose zone properties using global optimization, Water Resour. Res., 40, W06503, doi:10.1029/2003WR002706.
275. Wagner, W., K. Scipal, C. Pathe, D. Gerten, W. Lucht, and B. Rudolf (2003), Evaluation of the agreement between the first global remotely sensed soil moisture data with model and precipitation data, J. Geophys. Res., 108 (D), 19, doi:10.1029/2003JD003663.
276. Wagner, W., G. Blöschl, P. Pampaloni, J. C. Calvet, B. Bizzarri, J. P. Wigneron, and Y. Kerr (2007), Operational readiness of microwave remote sensing of soil moisture for hydrologic applications, Nord. Hydrol., 38, 1-20, doi:10.2166/nh.2007.029. (Pubitemid 46210865)
277. Walker, J. P., G. R. Willgoose, and J. D. Kalma (2001a), One-dimensional soil moisture profile retrieval by assimilation of near-surface measurements: A simplified soil moisture model and field application, J. Hydrometeorol., 2, 356-373, doi:10.1175/1525-7541 (2001) 002<0356: ODSMPR>2.0.CO;2.
278. Walker, J. P., G. R. Willgoose, and J. D. Kalma (2001b), One-dimensional soil moisture profile retrieval by assimilation of near-surface observations: A comparison of retrieval algorithms, Adv. Water Resour., 24, 631-650, doi:10.1016/S0309-1708 (00) 00043-9.
279. Walker, J. P., G. R. Willgoose, and J. D. Kalma (2002), Three-dimensional soil moisture profile retrieval by assimilation of near-surface measurements: Simplified Kalman filter covariance forecasting and field application, Water Resour. Res., 38(12), 1301, doi:10.1029/2002WR001545.
280. Ward, A. L., Z. F. Zhang, and G. W. Gee (2006), Upscaling unsaturated hydraulic parameters for flow through heterogeneous anisotropic sediments, Adv. Water Resour., 29, 268-280, doi:10.1016/j.advwatres. 2005.02.013.
281. Wendroth, O., G. G. Katul, M. B. Parlange, C. E. Puente, and D. R. Nielsen (1993), A nonlinear filtering approach for determining hydraulic conductivity functions in field soils, Soil Sci., 156, 293-301, doi:10.1097/00010694-199311000-00001.
282. Wendroth, O., W. Pohl, S. Koszinski, H. Rogasik, C. J. Ritsema, and D. R. Nielsen (1999a), Spatio-temporal patterns and covariance structures of soil water status in two northeast German field sites, J. Hydrol., 215, 38-58, doi:10.1016/S0022-1694 (98) 00260-1.
283. Wendroth, O., H. Rogasik, S. Koszinski, C. J. Ritsema, L. W. Dekker, and D. R. Nielsen (1999b), State-space prediction of field-scale soil water content time series in a sandy loam, Soil Tillage Res., 50, 85-93, doi:10.1016/S0167- 1987 (98) 00201-3.
284. Western, A. W., and G. Blöschl (1999), On the spatial scaling of soil moisture, J. Hydrol., 217, 203-224, doi:10.1016/S0022-1694 (98) 00232-7.
285. Western, A. W., and R. B. Grayson (1998), The Tarrawarra data set: Soil moisture patterns, soil characteristics, and hydrological flux measurements, Water Resour. Res., 34, 2765-2768, doi:10.1029/98WR01833.
286. Western, A. W., R. B. Grayson, G. Blöschl, G. R. Willgoose, and T. A. McMahon (1999), Observed spatial organization of soil moisture and its relation to terrain indices, Water Resour. Res., 35, 797-810, doi:10.1029/1998WR900065. (Pubitemid 29111809)
287. Western, A. W., R. B. Grayson, and G. Blöschl (2002), Scaling of soil moisture: A hydrologic perspective, Annu. Rev. Earth Planet. Sci., 30, 149-180, doi:10.1146/annurev. earth.30.091201.140434.
288. Western, A. W., S. L. Zhou, R. B. Grayson, T. A. McMahon, G. Blöschl, and D. J. Wilson (2004), Spatial correlation of soil moisture in small catchments and its relationship to dominant spatial hydrological processes, J. Hydrol., 286, 113-134, doi:10.1016/j.jhydrol.2003.09.014. (Pubitemid 38203952)
289. Wetzel, P. J., and J. T. Chang (1987), Concerning the relationship between evapotranspiration and soil moisture, J. Clim. Appl. Meteorol., 26, 18-27, doi:10.1175/1520-0450 (1987) 026<0018:CTRBEA>2.0.CO;2.
290. Wilson, D. J., A. W. Western, and R. B. Grayson (2005), A terrain and databased method for generating the spatial distribution of soil moisture, Adv. Water Resour., 28, 43-54, doi:10.1016/j.advwatres.2004.09.007. (Pubitemid 40077366)
291. Wilson, R. C., R. S. Freeland, J. B. Wilkerson, and R. E. Yoder (2003), Inferring subsurface morphology from transient soil moisture patterns using electrical conductivity, Trans. ASAE, 46, 1435-1441.
292. Wöhling, T., J. A. Vrugt, and G. F. Barkle (2008), Comparison of three multiobjective optimization algorithms for inverse modeling of vadose zone hydraulic properties, Soil Sci. Soc. Am. J., 72, 305-319, doi:10.2136/ sssaj2007.0176. (Pubitemid 351399322)
293. Ye, M., R. Khaleel, and T. C. J. Yeh (2005), Stochastic analysis of moisture plume dynamics of a field injection experiment, Water Resour. Res., 41, W03013, doi:10.1029/2004WR003735. (Pubitemid 40589255)
294. Yeh, T. C. J., M. Ye, and R. Khaleel (2005), Estimation of effective unsaturated hydraulic conductivity tensor using spatial moments of observed moisture plume, Water Resour. Res., 41, W03014, doi:10.1029/2004WR003736. (Pubitemid 40589256)
295. Yeh, W. W. G. (1986), Review of parameter identification procedures in groundwater hydrology: The inverse problem, Water Resour. Res., 22, 95-108, doi:10.1029/WR022i002p00095.
296. Yoo, C. (2001), Sampling of soil moisture fields and related errors: Implications to the optimal sampling design, Adv. Water Resour., 24, 521-530, doi:10.1016/S0309-1708 (00) 00033-6.
297. Zhou, Q. Y., J. Shimada, and A. Sato (2001), Three-dimensional spatial and temporal monitoring of soil water content using electrical resistivity tomography, Water Resour. Res., 37, 273-285, doi:10.1029/2000WR900284. (Pubitemid 32111435)