关键词: 湿地土壤, 入渗, 毛管吸水, 黄河三角洲, 不同容重, 模型拟合

Abstract: The Yellow River Delta wetland soil was taken as the research object, and indoor soil column experiment method was used to set 1.3, 1.4, 1.5g?cm-3 for 3 different bulk densities, and the experimental duration was 120min. The capillary water absorption and infiltration processes of wetland saline alkali soil were measured, and the dynamic regularity was also fitted by Philip model and Kostiakov model to understand the characteristics of soil capillary water process and movement in the wetland saline alkali soil of the Yellow River Delta. The results showed that under different bulk density conditions, the dynamic changes of capillary absorbed water for wetland saline alkali soil were the same as those of non-saline-alkali soils. Under the same conditions, the index values of infiltration process were greater than the capillary absorbed water process. The initial infiltration rate and steady infiltration rate of infiltration for different bulk density soils were 0.87-1.93cm?min-1 and 0.028-0.051cm?min-1, respectively. And the corresponding indices of capillary water absorption were 0.32-0.43cm?min-1 and 0.025-0.034cm?min-1, respectively. At 60min, wetting front depth and cumulatively infiltration of infiltration reached 13.58-17.62cm and 4.95-6.99cm for different bulk density soils, which is 1.19-1.22 times and 1.13-1.29 times of capillary absorbed water at the same time. In the 120min experiment, there was a significant positive correlation between capillary water rising height and wetting front depth of infiltration, cumulative absorbed water amount and infiltration amount(P＜0.05). Using the Philip model and the Kostiakov model simulated the capillary water absorption and infiltration process. And the two models have good adaptability for three kinds of bulk density soils, but the Philip model was the best to simulate the capillary absorbed water process, the R2 values were greater than 0.9639. And the Kostiakov model was more suitable for the simulation of infiltration process, the R2 values were greater than 0.8819.

Key words: Wetland soil, Infiltration, Capillary absorbed water, The Yellow River Delta, Different bulk density, Model simulation