Study on Impact of Soil Bulk Density on Infiltration Properties of Silt Soil in Coastal Reclamation Regions

In order to determine the effects of soil bulk density on infiltration properties of silt soil in coastal reclamation regions,the dynamic changes of infiltration rates,cumulative infiltration,and wetting front of soil water under different bulk density of silt soil and yellow brown soil were explored by one dimension vertical infiltration experiment in this paper.The results showed that soil infiltration processes were greatly affected by soil bulk density.Infiltration capacity indicated by infiltration rate,accumulative infiltration and wetting front depth of the two experimental soils decreased along with increasing soil bulk density.The indexes of infiltration capacity had significantly negative correlation with soil bulk density.For the two experimental soils,the parameter of K in Kostiakov infiltration equations which meant initial infiltration rate decreased along with increasing soil bulk density,but there were not significant differences of the another parameter of α which meant infiltration decaying rate.The relationship between the wetting front and time can be fitted well by one short power progressional solution of the Philip infiltration equation.The changing trends of the parameters of λ and x indicated that the both actions of matrix potential gradient and gravity decreased gradually with increasing soil bulk density for the two experimental soils.Profile soil moisture of silt soil was simulated well by a 1-D algebraic model,and the theoretical values were more accurate as the soil bulk density increased.