The infiltration of melted snow water and rainwater into snow can drastically change the form of snow layers. This process is an important factor affecting wet snow avalanches. Accordingly, numerous field surveys and cold room experiments have been conducted to investigate the distribution of water in snow. The common methods of water content measurement (calorimetric and dielectric methods) are implemented by disturbing snow samples to measure them. However, the resolutions obtained are of the order of several centimeters, which hinders the continuous measurement of the water content of a particular sample. Magnetic resonance imaging (MRI), which is typically used in the medical field, can be used to generate a high-resolution three-dimensional (3D) image of the water distribution in samples without destructing them. The luminance of images produced by MRI depends on the volumetric water content of the sample, with luminance increasing with volumetric liquid water content. Therefore, the volumetric liquid water content of the sample can be estimated from its luminance value. Considering this concept, we developed a method to measure the volumetric liquid water content of wet snow samples using MR images. To evaluate the developed method, we prepared several wet snow samples and measured their various volumetric liquid water contents using MRI (θ_MRI) and the calorimetric method (θ_cal). θ_MRI, and θ_cal showed good correlation when compared, with values in the range 0.02–0.46. Therefore, our system can accurately and non-destructively measure water content. The developed method using MRI can measure 3D volumetric liquid water contents with a high resolution (2 mm). Using the developed method, we investigated the hysteresis of the water retention curve of snow based on the measurements of a wetting process (boundary wetting curve) and a drying process (boundary drying curve) of the water retention curve for each sample. Our results indicate the existence of hysteresis in the snow water retention curves and the possibility of modeling it by adopting contexts of soil physics.

融化的雪水和雨水渗入雪中可以大大改变雪层的形式。这个过程是影响湿雪崩的重要因素。因此，已经进行了许多实地调查和冷藏室实验以调查雪中水的分布。常见的水分含量测量方法（量热法和介电法）是通过扰动雪样来进行测量的。但是，获得的分辨率约为几厘米，这阻碍了对特定样品中水含量的连续测量。通常在医学领域中使用的磁共振成像（MRI）可以用于生成样品中水分布的高分辨率三维（3D）图像，而不会破坏样品。MRI产生的图像的亮度取决于样品的体积水含量，亮度随体积液体水含量的增加而增加。因此，可以从其亮度值估计样品的体积液态水含量。考虑到这一概念，我们开发了一种使用MR图像测量湿雪样品的体积液态水含量的方法。为了评估开发的方法，我们准备了几个湿雪样本，并使用MRI（θ 我们开发了一种使用MR图像测量湿雪样品的体积液体含水量的方法。为了评估开发的方法，我们准备了几个湿雪样本，并使用MRI（θ 我们开发了一种使用MR图像测量湿雪样品的体积液体含水量的方法。为了评估开发的方法，我们准备了几个湿雪样本，并使用MRI（θ_核磁共振）和量热法（θ_卡）。θ_核磁共振和θ_卡比较时显示出良好的相关性，范围在0.02–0.46之间。因此，我们的系统可以准确无损地测量水含量。使用MRI开发的方法可以以高分辨率（2 mm）测量3D体积液体水含量。使用开发的方法，我们基于每个样品的保水曲线的润湿过程（边界润湿曲线）和干燥过程（边界干燥曲线）的测量结果，研究了雪的保水曲线的滞后现象。我们的结果表明，雪水滞留曲线中存在滞后现象，并且有可能通过采用土壤物理学的上下文对其进行建模。