Management of Snow Avalanche Risk in the Ski Areas of the Southern Carpathians-Romanian Carpathians - Sustainable Development in Mountain Regions: Southeastern Europe - page 107

10.3.1 Terrain Factors
Terrain factors are represented by elevation, slope and aspect. Altitude is essential
for skiing activities, and for the latitude of temperate climate in which our country
is located, it has to be of at least 1,000 m (Besancenot, 1990 ) in order to maintain a
favourable snow layer for at least 3 months/year.
Slope represents another factor of great importance for skiing activities. This
is the element that separates the categories of this activity's practitioners into two
large categories: skiers and beginners. The first category was defined as users of
skis, snowboards or other gravity-propelled recreational devices whose design and
function allow users a significant degree of control over speed and direction on
snow (Penniman, 1999 , p. 36) and as for beginning skiers or beginners as: those
individuals who are using one or another of these devices for the first time or who
possess marginal abilities to turn or stop on slopes with incline greater than 20%
(Penniman, 1999 , p. 36).
Performing a more analytical classification in accordance with the degree of
slope declivity there have been established the following categories: beginners or
novices that make use of slope gradients with a declivity not higher than 11.5 ◦ ,
intermediates that use the slope gradients between 18 and 19 ◦ , advanced, who use
the slope gradients of 19 ◦ and experts who use slope gradients that surpass 19 ◦
or even 39 ◦ (Borgersen, 1977, quoted by Penniman, 1999 ; Gaylor and Rombold,
1964, quoted by Penniman, 1999 ). For economic exploitation we need to consider
the slopes between 10 and 45 ◦ . Any ski area needs to comprise all the categories of
slope gradients. It is a well known that most of the skiers would rather ski on slopes
under 30 ◦ and that the beginners will usually not surpass the ones over 10 ◦ .
Using the applications of some GIS programmes (CartaLinx, Idrisi Kilimanjaro,
ArcGIS) and making use of their working methods (Török, 2001 - 2002 ), we have
created the digital elevation model (Fig. 10.4 ) which we used in generating the the-
matic maps (elevation, slope and aspect) for the Bâlea ski area and for the Sinaia ski
area (Figs. 10.5 and 10.6 ).
The altitude of the ski trails is a crucial element for practicing the specific activ-
ities. The Bâlea ski area is situated at high altitudes where skiing is practiced on the
glacial cirque walls, just under the cliffs, within the cirque, but also along the glacial
valley. The elevation map highlights this mathematic element (Fig. 10.5 ).
The Bâlea ski area is endowed with trails that are not groomed or even named,
for that matter, which have high slopes, and can only be used by expert or advanced
skiers. The slope map points out the high degree of declivity for the studied area.
The values between 1 and 15 ◦ represent 6.9% (3.4 km 2 ), the values between 15
and 25 ◦ represent 18.1% (9 km 2 ), the values between 25 and 35 ◦ represent 11.1%
(5.52 km 2 ), the values between 25 and 35 ◦ represent 33.2% (16.4 km 2 ), the values
between 35 and 45 ◦ represent 31.8% (15.8 km 2 ) and the values above 45 ◦ represent
9.5% (4.7 km 2 ) from the total of the Bâlea area.
Another important topographic factor is the aspect of the slopes, especially
because it influences the insulation and the presence of the wind. For this purpose
we have constructed the aspect map. For the Bâlea ski area the aspect map shows