Analysis of parameters on soil water characteristic curves of different soil texture

Comparisons of the common used models for soil water characteristic curves were made,and the best model was selected.Soil water characteristic curve for five different texture soils of heavy loam,medium loam,light loam,tight sand and rough sand was successfully simulated with Van Genuchten equation.The variation tendency of soil water characteristic curve and its parameters were analyzed: water characteristic curve for rough sand changed sharply,but gently for tight sand,and light loam,and medium loam and heavy loam soils;curve shape factor n become bigger as the particle sizes increased and the content of physical clay particle reduced;alpha values for heavy clayed soil were found smaller larger for light soil.