A soil water characteristic curve (SWCC) model named as discrete-continuous multimodal van Genuchten model with a convenient parameter calibration method is developed to describe the relationship between soil suction and the water content of a soil with complex pore structure. The modality number N of the SWCC in the proposed model can be any positive integer (the so-called multimodal or N-modal SWCC). A unique set of parameters is determined by combining curve fitting and a graphical method based on the shape features of the SWCC in the log s–log S_e plane. In addition, a modality number reduction method is proposed to minimize the number of parameters and simplify the form of SWCC function. The proposed model is validated using a set of bimodal and trimodal SWCC measurements from different soils, which yield a strong consistency between the fitted curves and the measured SWCC data. The uniqueness in the set of parameters provides the possibility to further improve the proposed model by correlating the parameters to soil properties and state parameters.

开发了一种名为离散-连续多模态 van Genuchten 模型的土壤水分特征曲线 (SWCC) 模型，该模型具有方便的参数校准方法，用于描述土壤吸力与具有复杂孔隙结构的土壤含水量之间的关系。所提出模型中 SWCC的模态数N可以是任何正整数（所谓的多模态或N模态SWCC）。一组独特的参数是通过结合曲线拟合和基于 SWCC 在 log s –log S _{e 中}的形状特征的图形方法确定的飞机。此外，提出了一种模态数约简方法，以最大限度地减少参数数量并简化SWCC函数的形式。使用一组来自不同土壤的双峰和三峰 SWCC 测量来验证所提出的模型，这在拟合曲线和测量的 SWCC 数据之间产生了很强的一致性。参数集的唯一性提供了通过将参数与土壤特性和状态参数相关联来进一步改进所提出的模型的可能性。