Study on interpolation of soil grain-size sparse distribution

This study compares the cubic spline interpolation method and several kinds of cumulative distribution curve fitting equations of soil particles in order to reduce the calculation error of the permeability caused by the interpolation error of the grain-size distribution to a certain extent. The soil samples are selected from UNSODA database for interpolation verification, and the result shows the reliability of the interpolation conversion to a some degree. In addition, methods have different adaptability to various soil textures, and the appropriate one can be selected through statistical methods. So interpolation methods are selected for different soil textures of HWSD in the research area. And the known particle size distribution of the interpolation samples has a limited influence on the interpolation results. (paper)