Vol11 No.1: 98-109
【Title】Temporal Stability of Apparent Soil Electrical Conductivity Measured by Electromagnetic Induction Techniques
【Author】LIAO Kai-hua1, ZHU Qing1*, James DOOLITTLE2
【Addresses】1 State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China; 2 USDA-NRCS, National Soil Survey Center, 11 Campus Blvd., Suite 200 Newtown Square, PA 19073, USA
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【Citation】Liao KH, Zhu Q, Doolittle J (2014) Temporal stability of apparent soil electrical conductivity measured by electromagnetic induction techniques. Journal of Mountain Science 11(1). DOI: 10.1007/s11629-012-2630-0
【Abstract】Assessing and managing the spatial variability of hydropedological properties are important in environmental, agricultural, and geological sciences. The spatial variability of soil apparent electrical conductivity (ECa) measured by electromagnetic induction (EMI) techniques has been widely used to infer the spatial variability of hydrological and pedological properties. In this study, temporal stability analysis was conducted for measuring repeatedly soil ECa in an agricultural landscape in 2008. Such temporal stability was statistically compared with the soil moisture, terrain indices (slope, topographic wetness index (TWI), and profile curvature), and soil properties (particle size distribution, depth to bedrock, Mn mottle content, and soil type). Locations with great and temporally unstable soil ECa were also associated with great and unstable soil moisture, respectively. Soil ECa were greater and more unstable in the areas with great TWI (TWI > 8), gentle and concave slope (slope < 3%; profile curvature > 0.2). Soil ECa exponentially increased with depth to bedrock, and soil profile silt and Mn mottle contents (R2 = 0.57), quadratically (R2 = 0.47), and linearly (R2 = 0.47), respectively. Soil ECa was greater and more unstable in Gleysol and Nitosol soils, which were distributed in areas with low elevation (< 380 m), thick soil solum (> 3 m), and fluctuated water table (shallow in winter and spring but deep in summer and fall). In contrast, Acrisol, Luvisol, and Cambisol soils, which are distributed in the upper slope areas, had lower and more stable soil ECa. Through these observations, we concluded that the temporal stability of soil ECa can be used to interpret the spatial and temporal variability of these hydropedological properties.
【Keywords】Geophysics; Pedology; Soil hydrology; Soil water content