468
A.-E. Briciu et al.
near the river gauge is more effective in explaining the river behavior than the regional
climate data from an official meteorological network.
Lundquist and Cayan [18] showed the wide variety of streamwater flow profiles
across USA caused by diverse natural factors. Gribovszki et al. [15] have written a
comprehensive review on the literature about diurnal oscillations in streamflow rates.
Studies on the river temperature are also reviewed in recent papers [12, 30].
The diurnal evolution of the rivers analyzed in this chapter was previously directly
or indirectly discussed in scientific articles of Briciu and Oprea-Gancevici [9] and
Briciu et al. [6–8, 10]; rivers fed by thermal groundwaters have a different local
thermal regime due to the quasi-constant temperature of such waters.
The good understanding of the diurnal cycle is useful for good prediction of a
streamwater parameter, such as temperature [26].
14.3 Geographic Description of the Study Area
and Measurement Sites
14.3.1 General Description of the Study Area
The study area is located in the Romanian Carpathians and the Moldavian Plateau
(Fig. 14.1). 2/3 of the 21 sites used for measuring rivers are placed in the mountain
area. The terrain elevation of the chosen sites ranges from 118 m above sea level
(a.s.l.) (minimum, Cerna River downstream of B˘ aile Herculane) to 810 m a.s.l. (maximum, Dorna River upstream of Vatra Dornei). In general, the selected sites can be
found in river valleys, at elevations between 300 and 400 m a.s.l.
The geology of the studied sites is dominated by carbonaceous rocks in the studied
areas of western Romania and site number 21 (S , ug˘ au Gorge). In sites 1–8, volcanic
rocks are also present. Sites 9–20 are dominated by sedimentary and metamorphic
rocks; friable sedimentary rocks are present in the plateau sites.
The climate of Romania is temperate continental with more precipitation in the
sites from Apuseni Mountains (Western Romanian Carpathians, sites 1–5) and Southern Carpathians (sites 6–8) than in Outer Eastern Carpathians (sites 9, 10, 16, 18, 20,
21) and Moldavian Plateau (sites 11–14, 15, 17, 19). The rainfall amount also greatly
varies with terrain elevation, slope aspect and the presence or absence of foehn; thus,
the annual sum of precipitation ranges from around 550 mm (some plateau areas,
mountain valleys with foehn) to approximately 800 mm (higher valleys, on slopes
with western aspect).
The air thermal amplitude is generally higher in the areas with fewer atmospheric
precipitations. In the area around Geoagiu-B˘ ai settlement (sites 1–3), the mean annual
air temperature was 10.6 °C during 1961–2010 [7]. In the area around Moneasa
settlement (sites 4 and 5), the mean air temperature was 7.9 °C during 1961–2010
[6], while, in the area around B˘ aile Herculane settlement (sites 6–8), the mean air
temperature was 8 °C during the same time interval [10]. The sites in northern
A.-E. Briciu et al.
near the river gauge is more effective in explaining the river behavior than the regional
climate data from an official meteorological network.
Lundquist and Cayan [18] showed the wide variety of streamwater flow profiles
across USA caused by diverse natural factors. Gribovszki et al. [15] have written a
comprehensive review on the literature about diurnal oscillations in streamflow rates.
Studies on the river temperature are also reviewed in recent papers [12, 30].
The diurnal evolution of the rivers analyzed in this chapter was previously directly
or indirectly discussed in scientific articles of Briciu and Oprea-Gancevici [9] and
Briciu et al. [6–8, 10]; rivers fed by thermal groundwaters have a different local
thermal regime due to the quasi-constant temperature of such waters.
The good understanding of the diurnal cycle is useful for good prediction of a
streamwater parameter, such as temperature [26].
14.3 Geographic Description of the Study Area
and Measurement Sites
14.3.1 General Description of the Study Area
The study area is located in the Romanian Carpathians and the Moldavian Plateau
(Fig. 14.1). 2/3 of the 21 sites used for measuring rivers are placed in the mountain
area. The terrain elevation of the chosen sites ranges from 118 m above sea level
(a.s.l.) (minimum, Cerna River downstream of B˘ aile Herculane) to 810 m a.s.l. (maximum, Dorna River upstream of Vatra Dornei). In general, the selected sites can be
found in river valleys, at elevations between 300 and 400 m a.s.l.
The geology of the studied sites is dominated by carbonaceous rocks in the studied
areas of western Romania and site number 21 (S , ug˘ au Gorge). In sites 1–8, volcanic
rocks are also present. Sites 9–20 are dominated by sedimentary and metamorphic
rocks; friable sedimentary rocks are present in the plateau sites.
The climate of Romania is temperate continental with more precipitation in the
sites from Apuseni Mountains (Western Romanian Carpathians, sites 1–5) and Southern Carpathians (sites 6–8) than in Outer Eastern Carpathians (sites 9, 10, 16, 18, 20,
21) and Moldavian Plateau (sites 11–14, 15, 17, 19). The rainfall amount also greatly
varies with terrain elevation, slope aspect and the presence or absence of foehn; thus,
the annual sum of precipitation ranges from around 550 mm (some plateau areas,
mountain valleys with foehn) to approximately 800 mm (higher valleys, on slopes
with western aspect).
The air thermal amplitude is generally higher in the areas with fewer atmospheric
precipitations. In the area around Geoagiu-B˘ ai settlement (sites 1–3), the mean annual
air temperature was 10.6 °C during 1961–2010 [7]. In the area around Moneasa
settlement (sites 4 and 5), the mean air temperature was 7.9 °C during 1961–2010
[6], while, in the area around B˘ aile Herculane settlement (sites 6–8), the mean air
temperature was 8 °C during the same time interval [10]. The sites in northern