Estimating Soil Water Contents from Soil Temperature Measurements by Using an Adaptive Kalman Filter

Abstract A simple soil heat transfer model is used together with an adaptive Kalman filter to estimate the daily averaged soil volumetric water contents from diurnal variations of the soil temperatures measured at different depths. In this method, the soil water contents are estimated as control variables that regulate the variations of soil temperatures at different depths and make the model nonbiased, while the model system noise covariance matrix is estimated by the covariance-matching technique. The method is tested with soil temperature data collected during 1–31 July 2000 from the Soil Water and Temperature System (SWATS) within the Oklahoma Atmospheric Radiation Measurement (ARM) central facilities at Lamont. The estimated soil water contents are verified against the observed values, and the rms differences are found to be small. Sensitivity tests are performed, showing that the method is reliable and stable.

[1]  G. A. Nakshabandi,et al.  Thermal conductivity and diffusivity of soils as related to moisture tension and other physical properties , 1965 .

[2]  A. Jazwinski.  Stochastic Processes and Filtering Theory , 1970 .

[3]  R. Mehra.  Approaches to adaptive filtering , 1972 .

[4]  O. Johansen.  Thermal Conductivity of Soils , 1977 .

[5]  G. Hornberger,et al.  Empirical equations for some soil hydraulic properties , 1978 .

[6]  J. Deardorff.  Efficient prediction of ground surface temperature and moisture, with inclusion of a layer of vegetation , 1978 .

[7]  R. Stewart.  The atmosphere boundary layer , 1979 .

[8]  E. Youngs,et al.  Fundamentals of Soil Physics. , 1982 .

[9]  R. Pielke,et al.  Simulation of the effects of surface fluxes of heat and moisture in a mesoscale numerical model: 1. Soil layer , 1981 .

[10]  P. Milly.  Moisture and heat transport in hysteretic, inhomogeneous porous media: A matric head‐based formulation and a numerical model , 1982 .

[11]  P. Koorevaar,et al.  Elements of soil physics , 1985 .

[12]  R. Pielke.  Mesoscale Meteorological Modeling , 1984 .

[13]  G. Hornberger,et al.  A Statistical Exploration of the Relationships of Soil Moisture Characteristics to the Physical Properties of Soils , 1984 .

[14]  Gaylon S. Campbell,et al.  Soil physics with BASIC :transport models for soil-plant systems , 1985 .

[15]  S. Planton,et al.  A Simple Parameterization of Land Surface Processes for Meteorological Models , 1989 .

[16]  Chris B. M. te Stroet,et al.  Using Kalman Filtering to Improve and Quantify the Uncertainty of Numerical Groundwater Simulations: 1. The Role of System Noise and Its Calibration , 1991 .

[17]  James R. Wang,et al.  Active and passive microwave measurements of soil moisture in FIFE , 1992 .

[18]  Marc B. Parlange,et al.  Physical basis for a time series model of soil water content , 1992 .

[19]  J. Walsh,et al.  Determination of soil moisture distribution from impedance and gravimetric measurements , 1992 .

[20]  Gabriel G. Katul,et al.  Evaporation and the field scale soil water diffusivity function , 1993 .

[21]  Richard H. Cuenca,et al.  Variation in soil parameters: Implications for modeling surface fluxes and atmospheric boundary-layer development , 1994 .

[22]  Weeratunge Malalasekera,et al.  An introduction to computational fluid dynamics - the finite volume method , 2007 .

[23]  Pedro Viterbo,et al.  An Improved Land Surface Parameterization Scheme in the ECMWF Model and Its Validation. , 1995 .

[24]  Alexey Kaplan,et al.  Mapping tropical Pacific sea level : Data assimilation via a reduced state space Kalman filter , 1996 .

[25]  C. Reece.  Evaluation of a Line Heat Dissipation Sensor for Measuring Soil Matric Potential , 1996 .

[26]  Eric F. Wood,et al.  The Effect of Soil Thermal Conductivity Parameterization on Surface Energy Fluxes and Temperatures , 1998 .

[27]  M. Parlange,et al.  On water vapor transport in field soils , 1998 .

[28]  Peter A. Troch,et al.  Multifrequency radar observations of bare surface soil moisture content: A laboratory experiment , 1999 .

[29]  E. Barker,et al.  An Air–Soil Layer Coupled Scheme for Computing Surface Heat Fluxes , 1999 .

[30]  Marc B. Parlange,et al.  Combined spatial and kalman filter estimation of optimal soil hydraulic properties , 1999 .

[31]  Qin Xu,et al.  Computing Surface Fluxes from Mesonet Data , 1999 .

[32]  Thomas J. Jackson,et al.  Remote sensing and estimation of root zone water content , 2001 .

[33]  John D. Albertson,et al.  Multi-scale assimilation of surface soil moisture data for robust root zone moisture predictions , 2003 .

[34]  J. M. Schneider,et al.  Spatiotemporal Variations in Soil Water: First Results from the ARM SGP CART Network , 2003 .

[35]  Binbin Zhou,et al.  Retrieving soil water contents from soil temperature measurements by using linear regression , 2003 .