2.1.1. Moisture Content and Density

The moisture content of peat was measured by the low-temperature drying method specified in GB/T 16913-2008. The density of the peat was determined using the pycnometer method according to GB/T 16913-2008. After calculation, the moisture content and density of the peat substate were 26.69% and 1560 kg·m<sup>−</sup>3, respectively.

#### 2.1.2. Stacking Angle

The injection limited bottom surface method, according to GB/T 11986-1989, was used to measure the stacking angle of the peat. The measuring device was, mainly, composed of a fixed frame, a funnel, and a steel plate. The front-view image of the peat pile was captured by a high-definition camera, and computer image processing technology was used to process the images. The software MATLAB was used to extract the image boundary pixels through edge detection, and the software Origin was used to pick up the boundary points and was further subjected to polynomial fitting. The arc tangent of the slope of the tangent line of the fitted curve was the stacking angle. The measured value of the stacking angle of the peat was 51.15◦.
