geographia - Studia

V. SOROCOVSCHI, W. SCHREIBER, ŞT. BILAŞCO, CS. HORVATH
As a result of the drainage network deepening, the relief energy represents a
parameter that describes the altimetric amplitude on which the actual geomorphic processes
could develop.
Fragmentation depth is a determinant factor in the transformation of potential energy
into kinetic energy. The values of this parameter are extremely variable within the analyzed
geographic space.
The maximal values, grading between 200 and 250 m describe small areas in
Dejului (2,1%) and Simişna-Surduc Hills (4,4%) and represent only 1,8% from the region’s
total surface (Figure 6). These values are determined by the closeness to the Someş low base
level and to Dej and Jibou local subsidence (Figure 7). The increased relief energy renders
difficult the inhabitants’ or goods’ access or evacuation in case of disasters. The values between
100 and 150 m are the most frequent in all the geographic subunits, reaching 46,5% from
the studied territory. The human settlements are located in areas with decreased relief energy,
between 0 and 100 m, category that represents 37,1% from the total surface and 51,9% in
Clujului Hills, with a higher settlements density than in Dejului and Simişna-Surduc Hills,
where this relief energy category describes only 32,6%, respectively 18,3% from their
territory.
2. 4. Relief Fragmentation Density
Fig. 8. Relief fragmentation density map in the Southern
part of the Someşan Plateau.
The petrographic differences
impose variations of the relief fragmentation
density and determine
different mechanisms in relief
modeling. The distribution of the
horizontal fragmentation classes is
very mosaicked, a large specter of
values, with very close weights,
being identified (Figure 8).
The maximum weight belongs
to the class with values grading
between 0 and 0,5 km/km 2 (22, 3%),
succeeded by that of 1 – 1,5 km/km 2 .
Similar weights (17,1 %) are characteristic
for the classes of 0,5 - 1 km/
km 2 , respectively 1,5 - 2 km/km 2 .
The horizontal fragmentation
maximal values (over 2,5 km/km 2 )
have a quite similar distribution in
Clujului (7,5%) and Dejului (6,1%)
Hills, while in Simişna-Surduc Hills
they are rather high (18,4%), contributing
to the triggering of ravines,
torrents or landslides.
20