考虑非饱和浸润区的改进Green-Ampt模型

经典Green-Ampt入渗模型计算简单，广泛应用于土壤入渗问题的研究，但在湿润锋处理上采用明显的干湿分离界面，存在一定的理论假设。鉴于此，基于饱和区−非饱和浸润区分层模型，结合达西定律，推导出入渗过程中饱和区厚度与非饱和浸润区厚度关系的理论公式，提出了水分剖面理论模型，消除了饱和区厚度和浸润区厚度的关系假设。在此基础上，建立了考虑土壤水分剖面形状和非饱和浸润区等效参数的改进Green-Ampt模型，并采用试验和有限元数值仿真对该模型进行了验证，结果表明：该模型有很高的精度，对不同类型的土有很好的适应性。同时该模型求解简单，参数物理意义明确，便于工程应用。

An improved Green-Ampt model considering unsaturated infiltration zone

The classical Green-Ampt infiltration model is simple in calculation and widely used in the study of soil infiltration. However, there exist some certain theoretical assumptions for the obvious dry-wet separation interface in the treatment of wetting front in the model. In view of this, based on the layered model of saturated zone-unsaturated infiltration zone and combined with Darcy’s law, a theoretical formula of the thickness relationship between the saturated zone and the unsaturated infiltration zone during infiltration was deduced in this paper and a theoretical model of water profile was proposed, which can eliminate the traditional assumption of the thickness relationship between the saturated zone and the unsaturated infiltration zone. On the basis, an improved Green-Ampt model considering the shape of soil moisture profile and the equivalent parameters in the unsaturated infiltration was established. The model was verified by experiments and finite element numerical simulation. The results show that the model has high accuracy and good adaptability to different types of soil. Meanwhile, the model is simple to solve with clear physical meaning parameters, and is convenient for engineering application.