Comparison of two methods for estimation of soil water content from measured reflectance

Abstract

Li, Y., Liu, S., Liao, Z. and and He, C. 2012. Comparison of two methods for estimation of soil water content from measured reflectance. Can. J. Soil Sci. 92: 845–857. Remote sensing (RS) technology has increasingly been used in soil water content estimation, but highly accurate estimates of soil water content are still difficult to obtain using this technique. This study aims to determine the wavelengths at which the reflectance is most sensitive to changes in soil water contents (θ). Four types of soils were selected and light reflectance (λ) was measured at different θ. Results showed that parabolic functions fit θ with measured λ very well but only for individual wavelengths. Multivariate linear functions of θ with measured λ at visually selected characteristic wavelengths led to improved predictions, but the coefficients of determination between the soil water content and measured reflectance (R 2 ranged from 0.788 to 0.925 for the four soils) were still not high for the studied soils. Stepwise multi...