558
R. B˘ atina¸ s et al.
Cri¸ sul Repede and Cri¸ sul Negru rivers belong to the western carpathian regime
(WC). These rivers are characterized by the early appearance of the spring high waters
(March–April), by flash floods in May–June due to the heavy rains that fall in this
period, followed by a hydrological drought from June until September, with some
disruptions due to the summer flash floods. The minimum flow occurs during autumn
in the depression area and during the winter in the mountain area. In the depression
area, it happens that the winter flow to overcome the spring flow (30–40%) due to the
snow melting and winter rains. In these conditions, the highest monthly flow rates
appear in February or March.
Cris , ul Alb river belongs on almost it entire length of western pericarpathic regime
type (WPc). This is explained by the low altitude of it catchment area, (only 610 m
at Cri¸ scior, in the upper basin, and 437 m at the Bocsig, in the lower basin). It is
noted the high instability of the winter regime. Due to the common heat waves that
appear in the cold period of the year, massive and rapid melting of the snow layer
takes place, so that the average winter flow is here approximately equal to the one
recorded in spring (over 30%). Also, the early summer flash floods are very intense,
with increased frequency, but of short duration. The minimum flow is observed in
the summer.
Somes , ul Mic basin belongs to the transylvanian carpathian type of regime (TC).
It is affected by the descent of air masses originating from the western north-western
circulation, that makes the rainfall to drop to 1000–1100 mm/year even at altitudes
of over 1 300 m. As a consequence, the values of the liquid average flow to stay
under 700 mm. Due to low snow reserves in the Gil˘ au Mountains and of convective
summer rains in the Somes , ul Rece basin, the share of summer runoff exceeds 25%
of the total runoff. The maximum flow is recorded especially in spring and summer,
and the minimum values especially in the winter. The transylvanian carpathian type
of regime is quite similar to the western carpathian one, only that it presents a much
more stable winter regime, without the snow meltdowns episodes: winter nivo-pluvial
flash floods have a frequency of only 10–20%.
The Arie¸ s river has a regime with the transition character. Due to its large basin
surface, the maximum flow rates result by cumulating the long duration rainfall or
correlated rainfall with snowmelt periods. Upper Aries , and its tributaries belong to
the transylvanian carpathian type of regime (TC), but with higher instability of the
winter regime.
Its tributary, Iara, deviate from the regime to the rest of the tributaries, distinguishing himself through a stable winter regime with late snow melting, with rich
flow from the heavy rains in May–July (it resembles much with the Some¸ sul Rece
regime). This makes the maximum monthly flow rate to be registered in May (nearly
equal to April), and with high flow volumes, also, during the summer (31.4%).
In terms of average flow, were analysed the main parameters that describe this
topic, with reference to the multiannual average values, maximum and minimum,
respectively, to the values of the specific average flow and drained layer at the hydrometric stations (Table 16.8). The used data were obtained from various bibliographic
sources, respectively from the statistical processing of the hydrological data strings,
generated at the level of territorial structures for hydric environment monitoring.
R. B˘ atina¸ s et al.
Cri¸ sul Repede and Cri¸ sul Negru rivers belong to the western carpathian regime
(WC). These rivers are characterized by the early appearance of the spring high waters
(March–April), by flash floods in May–June due to the heavy rains that fall in this
period, followed by a hydrological drought from June until September, with some
disruptions due to the summer flash floods. The minimum flow occurs during autumn
in the depression area and during the winter in the mountain area. In the depression
area, it happens that the winter flow to overcome the spring flow (30–40%) due to the
snow melting and winter rains. In these conditions, the highest monthly flow rates
appear in February or March.
Cris , ul Alb river belongs on almost it entire length of western pericarpathic regime
type (WPc). This is explained by the low altitude of it catchment area, (only 610 m
at Cri¸ scior, in the upper basin, and 437 m at the Bocsig, in the lower basin). It is
noted the high instability of the winter regime. Due to the common heat waves that
appear in the cold period of the year, massive and rapid melting of the snow layer
takes place, so that the average winter flow is here approximately equal to the one
recorded in spring (over 30%). Also, the early summer flash floods are very intense,
with increased frequency, but of short duration. The minimum flow is observed in
the summer.
Somes , ul Mic basin belongs to the transylvanian carpathian type of regime (TC).
It is affected by the descent of air masses originating from the western north-western
circulation, that makes the rainfall to drop to 1000–1100 mm/year even at altitudes
of over 1 300 m. As a consequence, the values of the liquid average flow to stay
under 700 mm. Due to low snow reserves in the Gil˘ au Mountains and of convective
summer rains in the Somes , ul Rece basin, the share of summer runoff exceeds 25%
of the total runoff. The maximum flow is recorded especially in spring and summer,
and the minimum values especially in the winter. The transylvanian carpathian type
of regime is quite similar to the western carpathian one, only that it presents a much
more stable winter regime, without the snow meltdowns episodes: winter nivo-pluvial
flash floods have a frequency of only 10–20%.
The Arie¸ s river has a regime with the transition character. Due to its large basin
surface, the maximum flow rates result by cumulating the long duration rainfall or
correlated rainfall with snowmelt periods. Upper Aries , and its tributaries belong to
the transylvanian carpathian type of regime (TC), but with higher instability of the
winter regime.
Its tributary, Iara, deviate from the regime to the rest of the tributaries, distinguishing himself through a stable winter regime with late snow melting, with rich
flow from the heavy rains in May–July (it resembles much with the Some¸ sul Rece
regime). This makes the maximum monthly flow rate to be registered in May (nearly
equal to April), and with high flow volumes, also, during the summer (31.4%).
In terms of average flow, were analysed the main parameters that describe this
topic, with reference to the multiannual average values, maximum and minimum,
respectively, to the values of the specific average flow and drained layer at the hydrometric stations (Table 16.8). The used data were obtained from various bibliographic
sources, respectively from the statistical processing of the hydrological data strings,
generated at the level of territorial structures for hydric environment monitoring.