基于土壤颗粒分布曲线的土壤水分特性曲线MV和AP模型应用研究——-基于土壤颗粒分布曲线

土壤水分特性曲线是土壤的基本性质，它的直接测量方法非常冗长耗时，间接方法成为重要途径之一。多种基于土壤颗粒分布曲线的预测模型因此得以提出，但各模型的实际应用效果仍缺乏充分检验。针对江苏常州水稻土等3种土样，基于土壤颗粒分布曲线，利用MV模型和AP模型预测土壤水分特性曲线，采用van Genuchten-Mualem公式，拟合得到了土壤水分特性曲线的基本参数值；通过对模型预测值和实测值的方差和AIC标准检验，对比了MV模型和AP模型，讨论两个模型在粉、沙壤土中的应用效果。研究表明：AP和MV模型均可以较好地预测粉、沙壤土两种土的土壤水分特性参数；两种模型在低负压时的预测效果优于高负压时；AP模型随着土壤粘粒含量的增加预测效果逐渐变差，MV模型与土壤粘粒含量之间无明显关系；对比两模型，AP模型优于MV模型；MV模型作为一种不含经验参数的简易模型，其预测精度仍有待改进。

Application of MV and AP Model to Predict Soil Moisture Characteristic Curve from Particle-size Distribution Curve

Soil moisture characteristic curve (SMCC) is a fundamental soil property and its direct measurement is tedious and time-consuming. Therefore, various indirect methods have been developed to predict SMCC from particle-size distribution (PSD). This study employed MV and AP model to predict SMCC from PSD. The parameters of SMCC were estimated by using van Genuchten-Mualem model. The estimated soil parameters from MV and AP　models and the estimated parameters from measured SMCC were examined by SSE and AIC indicator. The predicted soil water contents from two models were compared with the measured value. The results showed that 1) Both AP model and MV model are able to obtain the soil parameters in silty loam and sandy loam; 2) At the low-suction head section, two models produces better results than at the high-suction head section; 3) With the increase of clay particles, the performance of AP model deteriorates, but MV model seems not; 4) Comparing the two models, AP model generally works better than MV model. Although MV model is a simple model without any empirical parameter, but its application to real soil requires further study.