Fig. 1.
Location of the study area: a – a regional overview, B – a hillshaded relief of the catchment with analysed channels. Channels are signed with CH and followed numbers. Important drainage lines and ski infrastructure are marked, and C – a photograph of the catchment with ski run 2 (photo: D. Piątek).
Fig. 2.
Schematic diagram of selected measurements, black arrows and Greek letters show the way of measurement.
Fig. 3.
Photographs of characteristic parts of analysed channels: A – a part of Channel 2 with traces of lateral and deep erosion, B – a part of Channel 4 with a relatively high gradient, C – a part of Channel 8 with a 0.6-m-high step below the rockfloor, D – a step with typical height for catchment, Channel 3, E – part of Channel 7, fulfilled with material from a small landslide visible in the left corner (photos: a. Gołąb and D. Piątek).
Table 1.
Morphometry of analysed channels. SD is the standard deviation.
| Channel ID | Number of Reaches | Drainage area | Length | Channel gradient | Hillslope gradient | Valley bottom width | Channel/active zone width | Bed material size | Number of steps | Step height | Step height SD | Step spacing (m) | Step spacing SD | Step clast size (mm) | Step per channel length | Channels with skiing impact |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| [km2] | [m] | [m · m−1] | [°] | [m] | [mm] | [–] | [m] | [–] | [m] | [–] | [mm] | [–] | [–] | |||
| 1 | 3 | 0.01 | 77 | 0.27 | 26.75 | 1.97 | 0.63 | 68 | 28 | 0.38 | 17.38 | 1.41 | 0.89 | 220 | 0.36 | YES |
| 2 | 5 | 0.02 | 192 | 0.24 | 35.48 | 2.74 | 0.98 | 74 | 69 | 0.39 | 15.69 | 2.83 | 1.91 | 380 | 0.34 | YES |
| 3 | 5 | 0.14 | 223 | 0.24 | 35.39 | 1.80 | 1.80 | 84 | 50 | 0.4 | 12.43 | 4.05 | 2.52 | 450 | 0.22 | NO |
| 4 | 6 | 0.07 | 438 | 0.17 | 31.13 | 3.47 | 0.72 | 68 | 55 | 0.38 | 21.51 | 4.59 | 1.72 | 230 | 0.13 | NO |
| 5 | 2 | 0.05 | 161 | 0.25 | 33.55 | 2.05 | 0.45 | 66 | 50 | 0.41 | 18.24 | 2.18 | 1.36 | 540 | 0.31 | NO |
| 6 | 5 | 0.08 | 295 | 0.23 | 30.41 | 2.94 | 0.78 | 61 | 137 | 0.31 | 12.94 | 1.98 | 1.70 | 350 | 0.46 | NO |
| 7 | 3 | 0.14 | 199 | 0.24 | 32.42 | 1.83 | 0.50 | 68 | 43 | 0.44 | 15.04 | 5.71 | 4.47 | 350 | 0.22 | NO |
| 8 | 8 | 0.18 | 645 | 0.18 | 33.36 | 3.59 | 1.80 | 84 | 286 | 0.39 | 22.91 | 2.10 | 1.22 | 730 | 0.44 | YES |
Table 2.
Correlation matrix of parameters from all analysed channels. red marked statistically significant values.
| Variable | Bed material size | Step clast size | Hillslope gradient | Channel gradient | Step height avg. | Step height SD | Step spacing Avg. | Step spacing SD | Number of steps | Channel/active zone width | Valley bottom width |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Bed material size | |||||||||||
| Step clast size | 0.712 | ||||||||||
| Hillslope gradient | 0.482 | 0.390 | |||||||||
| Channel gradient | 0.213 | -0.063 | 0.263 | ||||||||
| Step height avg. | 0.147 | 0.044 | 0.388 | 0.253 | |||||||
| Step height SD | 0.080 | 0.044 | 0.220 | 0.049 | 0.713 | ||||||
| Step spacing avg. | –0.063 | –0.256 | 0.075 | –0.032 | 0.393 | 0.058 | |||||
| Step spacing SD | –0.208 | –0.289 | –0.090 | –0.192 | 0.002 | –0.273 | 0.629 | ||||
| Number of steps | –0.076 | 0.278 | –0.071 | –0.259 | –0.380 | –0.047 | –0.652 | –0.135 | |||
| Channel/active zone width | 0.321 | 0.368 | 0.383 | –0.153 | 0.071 | 0.036 | 0.021 | 0.076 | 0.128 | ||
| Valley bottom width | –0.159 | –0.060 | –0.365 | –0.356 | –0.184 | –0.044 | –0.143 | 0.115 | 0.355 | 0.091 | |
| Drainage area | 0.246 | 0.533 | 0.042 | –0.592 | –0.144 | –0.131 | 0.050 | 0.206 | 0.397 | 0.374 | 0.231 |
Fig. 4.
Distinctive correlations in the group of all analysed channels (reach averaged data), A – hillslope gradient versus bed material size; B – channel gradient versus drainage area.
Fig. 5.
Distinctive correlations in the group of channels without impact of ski runs (reach averaged data), A – hillslope gradient versus step clast size; B – step height versus step spacing.
Table 3.
Correlation matrix of parameters from channels without impact of skiing. Red marked statistically significant values.
| Variable | Bed material size | Step clast size | Hillslope gradient | Channel gradient | Step height avg. | Step height SD | Step spacing Avg. | Step spacing SD | Number of steps | Channel/active zone width | Valley bottom width |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Bed material size | |||||||||||
| Step clast size | 0.678 | ||||||||||
| Hillslope gradient | 0.705 | 0.716 | |||||||||
| Channel gradient | 0.108 | 0.030 | 0.399 | ||||||||
| Step height avg. | 0.184 | 0.005 | 0.406 | 0.175 | |||||||
| Step height SD | –0.037 | –0.119 | 0.198 | –0.053 | 0.626 | ||||||
| Step spacing avg. | –0.044 | –0.299 | –0.012 | 0.013 | 0.625 | 0.280 | |||||
| Step spacing SD | –0.179 | –0.282 | –0.340 | –0.096 | 0.172 | –0.212 | 0.567 | ||||
| Number of steps | –0.281 | 0.137 | –0.267 | –0.073 | –0.578 | –0.294 | –0.799 | –0.121 | |||
| Channel/active zone width | 0.611 | 0.455 | 0.392 | –0.028 | 0.079 | –0.078 | 0.181 | 0.142 | –0.190 | ||
| Valley bottom width | –0.304 | –0.449 | –0.773 | –0.323 | –0.326 | –0.179 | –0.085 | 0.222 | 0.165 | –0.169 | |
| Drainage area | 0.285 | 0.430 | 0.053 | –0.489 | 0.005 | –0.326 | 0.121 | 0.440 | 0.051 | 0.333 | 0.003 |
Fig. 6.
Distinctive correlations in the group of channels affected by ski runs (reach averaged data), A – drainage area versus channel gradient; B – channel width versus number of steps.
Table 4.
Correlation matrix of parameters from channels with impact of skiing. Red marked statistically significant values.
| Variable | Bed material size | Step clast size | Hillslope gradient | Channel gradient | Step height avg. | Step height SD | Step spacing Avg. | Step spacing SD | Number of steps | Channel/active zone width | Valley bottom width |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Bed material size | |||||||||||
| Step clast size | 0.718 | ||||||||||
| Hillslope gradient | 0.269 | 0.098 | |||||||||
| Channel gradient | 0.342 | –0.153 | 0.071 | ||||||||
| Step height avg. | 0.085 | 0.049 | 0.355 | 0.395 | |||||||
| Step height SD | 0.116 | 0.082 | 0.235 | 0.188 | 0.862 | ||||||
| Step spacing avg. | 0.158 | 0.000 | 0.616 | –0.292 | –0.081 | –0.105 | |||||
| Step spacing SD | –0.178 | –0.219 | 0.429 | –0.438 | –0.308 | –0.266 | 0.815 | ||||
| Number of steps | 0.027 | 0.333 | 0.188 | –0.590 | –0.142 | 0.111 | 0.058 | 0.100 | |||
| Channel/active zone width | –0.184 | 0.202 | 0.404 | –0.474 | –0.027 | 0.077 | –0.013 | 0.247 | 0.695 | ||
| Valley bottom width | –0.092 | 0.295 | 0.331 | –0.447 | 0.056 | 0.031 | 0.085 | 0.104 | 0.632 | 0.679 | |
| Drainage area | 0.224 | 0.599 | 0.033 | –0.729 | –0.307 | –0.033 | 0.045 | 0.056 | 0.763 | 0.572 | 0.510 |
Fig. 7.
Elevation changes in analysed channels in the period 2016–2023, in rectangle areas presented in Figure 8.
Fig. 8.
Close up on areas with elevation changes marked with rectangles on Figure 7; A – close up on Channel 2, in red rings marked results of headward erosion; B – close up on Channel 8 with zones with erosion and deposition; and C – close up on a small landslide on hillslopes of Channel 4.