Using Cubic Spline Interpolation to Estimate Vertical Soil Water Profile

1 Institute for Land Reclamation and Agricultural Mechanization, BG – 1080 Sofia, Bulgaria
2 National Institute of Meteorology and Hydrology, Bulgarian Academy of Sciences, BG – 1113 Sofia, Bulgaria


PATAMANSKA, G. and N. SLAVOV, 2007. Using cubic spline interpolation to estimate vertical soil water profile. Bulg. J. Agric. Sci., 13: 317-323

The modelling of the soil water flow under the various affecting factors such as meteorological conditions, irrigation, etc. is one of the main parts of the simulation model of the plant productivity. As an input for the model detailed measured data for soil water profile are required. The needed information is not fully available in the operational bulletins or handbooks of agricultural hydrology. In this paper cubic splines are employed for estimation and completion of the missing data and construction of the soil water profile up to 2 m depth. A procedure based on spline interpolation was developed and its applicability was tested with experimental data carried out for two crops: wheat and maize in 4-years period. The estimated profiles were compared to the measured ones. The results obtained for both crops exhibit sufficient correlation.

Key words: soil water, agro hydrology, spline interpolation, simulation models

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