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winter the floods frequency has smaller values (included within the 14 – 25% of total
floods). The most reduced frequency of the floods (with values between 14 and 25 % of
the total floods) is recorded in the Almaş-Agrij Depression but also in the Cluj - Dej
Hills in autumn.
floods
35
30
25
20
15
10
5
0
winter spring summer autum
season
Borsa
Luna de Jos
Maia
Figure 3. The seasonal flood frequency in Cluj and Dej Hills (1976-2004)
It is noticed, regarding the floods frequency during the seasons, a spatial differentiation
on the Cluj and Dej Hills, thus: on the rivers from the east of the unit (Olpret, Borşa,
Lonea) the number of floods during the summer has a very close value to that number
which represents the floods during the winter (34 floods during the summer, and 32
floods in winter); on the Nadăş and Căpuş Streams (Cluj Hills) the difference is
remarkable, the number of summer floods being much higher than the number of winter
floods (20 floods, 46 floods respectively). More over, this considerable difference is
found again in Almaş-Agrij Depression (29 floods, 45 floods respectively).
The monthly frequency of floods is maximum in March on rivers of the Cluj and
Dej Hills (Olpret, Lonea, Borşa, Nadăş, Căpuş), representing 17–23 % of all selected
floods. High values of the monthly frequency of floods formation have been recorded in
April and May. The lowest frequencies of floods took place on Olpret, Borşa and Lonea
rivers in October and November. There were no floods on Căpuş and Nadăş rivers in
November, within the studied interval, and in December there were recorded minimal
values of the floods frequency (1.9% of total) (Fig.4, Fig. 5)
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