荒漠草原灰钙土土壤入渗特征及测定方法比较

Soil Infiltration Characteristics and Determination Methods Comparison of Sierozem in Desert Steppe

为了研究荒漠草原土壤水分入渗特征,并对比不同方法间的差异,以宁夏天然草地地带性灰钙土为研究对象,采用双环法和环刀法测定其入渗过程,分析并比较2种方法的试验结果及影响因素,利用模型拟合土壤的水分入渗过程。结果表明:环刀法测得的初渗率、稳渗率、平均入渗率和达到稳渗时间均小于双环法,分别小了77.69%~94.67%,27.69%~52.88%,56.74%~64.79%,12.50%~42.5%。双环法更适宜采用Horton模型描述入渗速率随时间变化的过程;环刀法更适宜采用Kostiakov模型。土壤累计入渗量采用一元二次方程拟合效果最好,其决定系数R^2均在0.991以上。土壤物理性质对入渗特征的影响因土壤内部条件在2种试验方法中的差异而略有不同。

In order to study the characteristics of soil water infiltration in desert steppe and compare the differences among different determination methods,the sierozem of Ningxia natural grassland was taken as the research object.The infiltration process was determined by double-ring method and cutting ring method.The test results and influencing factors of the two methods were analyzed and compared.The models were used to fit the soil infiltration process.The results indicated that the initial infiltration rate,steady infiltration rate,average infiltration rate and steady infiltration time measured by the cutting ring method were all smaller than that of the double-ring method,which are 77.69%~94.67%,27.69%~52.88%,56.74%~64.79%and 12.50%~42.5%respectively.Double-ring method was more suitable to describe the process of infiltration rate changing with time by Horton model,Kostiakov model was more suitable for cutting ring method.Quadratic equation was the best fitting method for the cumulative infiltration of soil,and its determination coefficient R^2 was above 0.991.The influence of soil physical properties on infiltration characteristics was slightly different due to the difference of soil internal conditions in the two methods.