## 3 Materials and Methods  
### Field and Laboratory Photogrammetric Works  
Fieldworks were led during two expeditions in 2018 (10-26 September) and 2019 (15-29 August). We measured all the largest dome- and tepee-like hydration forms with internal caves and the largest hydration chambers using a laser range finger and tape measure. Smaller hydration domes and tepee-shaped forms of a few to several tens of centimeters in height and less than ca. 1.8 m in diameter in a plan view are very abundant at the site (e.g., see Section 4.1) (Figure 7 in [9]). These as well as badly damaged forms (Figure 2d,e) and some pressure ridges up to 1 m or more in height were omitted from our quantitative documentation. We also did not measure irregular detachments of the rock layers (see Section 4.1) and extensive, almost flat uplifts of these layers, with an extension of several meters or more. Our investigations focused on convex hydration landforms showing significant sizes--those that attain more than about 2 m in diameter. The basic identification criteria used for their recognition were as follows: (1) pronounced convex shape, (2) the presence of a cavity under the rock surface; when this cavity was invisible, then its presence was detected by the rumble sound during hitting the ground with a hammer. The hydration forms were recorded by direct measurements and photogrammetric methods using Unmanned Aerial Vehicle (UAV) and digital cameras. Photogrammetry was also used to visualize the bottom of the quarry and the individual forms. During field work, the form was identified with the assignation of a documentation number, its most important morphometric parameters (Table 2; Figure 3) and the location. The delimitation of the forms in the plan view was outlined on the basemap of the orthophotomap with the use of a portable mobile device (Lenovo Yoga Tab 3, Hong Kong, China). Joints and fractures were measured with a geological compass and distances with the laser rangefinder and the tape measure. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Name of Parameter** & **Symbol, Unit and Formula (If Applied)** & **Maximum-Minimum; Average Value** & **Number of Measurements** & **References** & **Simplified Frequency Distribution** \\ \hline Length * & a (m) & 1.86–23.05; 5.25 & 74 & [36]_modified; modified;_ [82; 83] & 7 \\ \hline Width & b (m) & 0.92–9.01; 8.38 & 74 & [36]_modified; modified;_ [82; 83] & 9 \\ \hline Relative height & h\({}_{\rm r}\) (m) & 0.33–2.09; 0.83 & 74 & [84]_modified_ & 6 \\ \hline Thickness of detached layer & e (m) & 0.06–0.46; 0.21 & 54 & [18; 36; 64] & 11 \\ \hline Coefficient of circularity & C (-) (a \(-\) b)/a & 0.04–0.73; 0.33 & 74 & [18; 36; 67] & 5 \\ \hline Azimuth of elongation orientation & Az (\({}^{\circ}\)) & 0–176 ***** & 84 & 68 & New \\ \hline Bulge degree & B (-) b/h\({}_{\rm r}\) & 1.82–8.58; 4.28 & 74 & [84] & 6 \\ \hline Fracture density & \(\begin{array}{c}\text{F}_{\text{D}}\text{(m/m${}^{2}$)}\\ \text{$\Sigma$Ls/P}\text{ ***}\end{array}\) & 0.04–3.38; 0.85 & 69 & [85; 86]_modified_ & 9 \\ \hline Length of the entrance line ** & — (m) & 0.30–4.52; 1.21 & 98 & New \\ \hline Azimuth of the entrance line ** & — (\({}^{\circ}\)) & 0–177 ***** & 92 & 98 & New \\ \hline Azimuth of entrance ** & — (\({}^{\circ}\)) & 0–350 ***** & 92 & [18] & 8 \\ \hline Direction of maximum lateral expansion & — (\({}^{\circ}\)) & 3–67, 80–115, 130–176 ***** & 66 & [66]_modified_ & 10 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Geomorphometric parameters measured and computed for 74 hydration forms, including symbol, unit, formula, maximum, minimum and average value, references and frequency distribution diagrams (horizontal axis has the same unit as the parameter, vertical axis is the number of measurements). The applied methodology of photogrammetric documentation is described in the previous work of the authors [7], the other papers [87; 88; 89], the instructions for the program used [90] and in the supplementary materials (Figure S1).