*6.2.4 Localisation of the hiking trail and morphodynamic processes threatening hiking trails*

The location of a hiking trail should be in accordance with, or in the least contradiction with, the natural conditions of the territory. Otherwise, there is devastation not only of the trail itself, but also of its surroundings and the process of their regeneration is slow (**Figures 16** and **17**).

The subsoil in the studied area is susceptible to various forms of destruction by exogenous processes. Therefore, it is suitable only for a slightly concentrated, soft form of tourism.

**Figure 16.** *Predné Meďodoly. Fading hiking trail, closed since 1978 (Piscová, 2010).*

**Figure 17.** *Trail to Ždiarska vidla (2142 m MSL), closed since 1978 (Piscová, 2010).*

*Impacts of Human Activities on the High Mountain Landscape of the Tatras… DOI: http://dx.doi.org/10.5772/intechopen.105601*

Routes of hiking trails on the south-western and south-eastern slopes of the Belianske Tatras are threatened by many processes [99] associated with avalanches, nivation, surface runoff, coming off of soil and weathered cover, debris flows, rock

**Figure 18.**

*Massive snow deposits covered the hiking trail after the avalanche event in April 2009 under the Ždiarska vidla (Hreško, 2009).*

rushing and landslides (**Figure 18a, b**). Processes that arise in the immediate vicinity of the trails and are bound to their course – processes of nivation (dominant processes), erosive processes, gravitational descent of the weathered cover, slopegravitational processes of the type of shallow landslides, eolithic processes in saddle and ridge positions.

Avalanches represent the process of movement of snow masses on mountain slopes, in avalanche troughs and in juvenile valleys. A special case of snow avalanches are "gliding avalanches", in which the soil-vegetation cover and the subsoil (including the trail) are destroyed almost in the entire width of the snow mass movement (**Figure 19**). An avalanche with a massive snow mass with a thickness of more than 2 meters and torn off fragments of rock substrate destroys vegetation and grinds the soil and weathered cover, which is documented by parallel grooves in the direction of the avalanche movement.

Another process endangering the trails associated with intense rainfall is debris flows. The limestone-dolomite subsoil of the exposed ridge of the Belianske Tatras provides a large amount of weathered, fragmentary material that forms the substantial mass of the flows. The most significant activation of debris streams occurred in 2016 (**Figure 20a, b**) at a precipitation intensity of more than 45 mm/h, which was confirmed by the analysis of the SHMI radar image.

The erosive effects of running water and concentrated surface runoff are mainly associated with torrential rains, which are involved in the fluviation of alpine ecosystems. Trails are in some places intersected by erosive grooves, which are formed in the gutters and on the bottoms of the juvenile valleys. Most often, the erosive effect is also manifested on the trails that represent local erosive bases (**Figure 21**) for the flowing surface water. This leads to significant destruction of trails and their deepening into more or less stable rock subsoil (**Figure 22**).

**Figure 19.** *The trail to Vyšné Kopské sedlo after a gliding avalanche (Hreško, 18 June 2009).*

*Impacts of Human Activities on the High Mountain Landscape of the Tatras… DOI: http://dx.doi.org/10.5772/intechopen.105601*

#### **Figure 20.**

*Activated debris flows on the SW slope under the Hlúpy vrch after an intense downpour on 24 June 2016 (Hreško, 6 July 2009).*

Nivation is a specific process, which is related to the long-term effect of snow fields on the hydric regime of the concave parts of slopes, especially if they are interrupted by a notch of a hiking trail. In the conditions of the SW slopes of the Belianske Tatras, we confirmed the occurrence of expansion cracks on the surface of the trails which were covered with remnants of snowfields for a longer time (**Figure 23a, b**).

**Figure 21.** *Fresh erosive groove near the trail under the avalanche trough of the Ždiarska vidla (Hreško, 6 July 2009).*

The slow melting of the snow led to an increased retention of melt water, which reduced the stability of the soil-weathering layer and subsequently formed longitudinal expansion cracks. Such sections of trails have a high potential for slow coming off and descent. This is manifested by the sudden bends and dents of the trails, including their surroundings.

Nivation-eolic effects are concentrated mainly in the sub-ridge, ridge, sub-peak and saddle positions. The eolic-deflationary effect is based on the turbulent, backward effect of the flowing wind, which causes blowing off and removal of finer amounts of soil cover or even the nivation of the exposed weathered cover in the upper parts of leeward slopes, especially on the edges of the ridges (**Figures 24** and **25**). The

*Impacts of Human Activities on the High Mountain Landscape of the Tatras… DOI: http://dx.doi.org/10.5772/intechopen.105601*

#### **Figure 22.**

*Intensive deep erosion of the hiking trail under Kopské sedlo after an intense downpour in June 2016 (Hreško, 14 September 2016).*

accumulation effect of both processes is destructive and does not allow a more successful process of vegetation succession. The eolic-nivation pads in the upper parts of the extremely steep slopes are often the source area of the initial debris flows, which, due to the smaller number of debris and fragments, may not reach the bottom of the slope, i.e. they remain "hanging" on the slope. The manifestations of wind erosion, more precisely the deflation of fine soil and weathering particles, focus mainly on the saddle and ridge positions of the Tatras. Another form conditioned by wind corrosion are eolic niches – pads with removed soil horizon of various shapes. Their edges are lined with overhangs, reinforced by root systems, which are intensively undermined by wind-blown particles. In cases of intense precipitation and snow melting, there is also a systematic washing out of niches and receding edges. Favourable conditions for the application of eolic deflation and corrosion are provided mainly by colourful shales
