用修正的Green-Ampt模型确定土壤入渗性能的速算方法

土壤入渗性能的确定对水文过程及其相关研究与应用具有重要的意义。该文在土壤入渗性能的水平土柱测量方法和Green-Ampt修正模型的基础上，推导出了Green-Ampt模型与修正模型之间的比例关系，进而提出了土壤入渗性能的速算模型。该计算模型在保证土壤入渗性能计算精度的前提下，计算过程较修正Green-Ampt模型有了很大的简化。将3种方法计算得到的土壤入渗率进行了比较，快速方法计算得到的土壤入渗性能与Green-Ampt修正模型计算得到的土壤入渗性能非常接近。在水量平衡原理的基础上得到3种方法计算结果误差分别为11.5%（Green-Ampt模型），0.66%（修正模型）和2.68%（快速计算模型）。表明快速计算方法具有很高的精度。新方法大大简化了修正模型的计算步骤。该文提出的土壤入渗性能速算法与水平土柱试验相结合，可以方便地应用于室内土壤入渗性能的测量，为水文循环/地表产流等相关研究提供便捷的土壤入渗性能计算工具。

Fast method for estimating soil infiltrability with modified Green-Ampt model

To quantify the soil infiltrability is of great importance for the study of the hydrological process and related researches and applications. A fast method for estimating soil infiltrability was proposed in this study based on the horizontal soil column measurement method and the modified Green-Ampt model according to the proportional relationship between the soil infiltrability estimated with the piston model and that calculated with the modified Green-Ampt one. The newly introduced fast model for estimating soil infiltrability was the simplification of the modified Green-Ampt infiltration model with relatively high accuracy. Comparisons were made among the results estimated with the three calculation models, which were the piston model, the modified Green-Ampt model and the fast estimation model. The results showed that the soil infiltrability estimated with the fast estimation model was very close to that calculated with the modified Green-Ampt model. The relative errors of these three methods were calculated based on the mass balance principle which were 11.5% for the piston model, 0.66% for the modified Green-Ampt model and 2.68% for the fast estimation model. The fast estimation method introduced in this study, combined with the horizontal soil column measurement method is applicable to laboratory studies of soil infiltrability. This method supplies a useful tool for the study of hydrologic circulation/overland flow and other relative fields.