540
R. B˘ atina¸ s et al.
The upper basin of Some¸ sul Mic is almost devoid of high permeability rocks due
to its overlapping over the granite platoon of Muntele Mare and over the crystalline
shale in the Gil˘ au Mountains. Only the sedimentary periphery of the Gil˘ au reservoir
area has a sedimentary substrate favorable to underground water infiltration.
The Middle Somes , basin is just the rest of drainage area, deployed at a very
low altimetric level, an area that drains the north-eastern low apophysis of Apuseni
Mountains—the Mese¸ s Mountains.
Its central axis, built of crystalline shale of poor consistency compared to the
Gil˘ au, Vl˘ adeasa massifs, etc., is quasi-impermeable. Its adjacent areas, on the western and eastern slopes, are occupied by sedimentary basins ( ¸
Simleu, with Zal˘ au
micro-depression to the west and Almas , -Agrij to the east). The rocks have a high
permeability and allow the creation of moderate underground water deposits—on
the hearth of the Zal˘ au basin there is even an artesian aquifer.
The Barc˘ au basin is formed on the northern slope of the Plopis , Mountains ( ¸
Ses),
the other low apophysis, situated in the northwest of the Apuseni Mountains.
The only space with some permeability of the component rocks is the rest of the
S , imleu Depression, which partially overlaps the Barc˘ au basin. The entire mountain
area is quasi-impermeable due to the same crystalline shale which is found underground.
16.2.2.2 Drainage Density (Density of the Relief Fragmentation)
As we mentioned at the beginning of this study, in the Apuseni, although we encounter
the most extensive endoreal areas in Romania, the morphometric parameters related
to surface flow are significant. Excepting the karst areas, river network density values
fall within the gap of 0.8–1.2 km/km
2 with local convergence areas, where they
sometimes exceed 1.8 km/km
2 (Câmpeni and Brad depression).
Drainage density, as a result of relief dynamics, records significantly higher values
compared to the density of the permanent network and gives a relevant image on the
surface liquid flow areas. The statistic analysis, from the information presented,
shows that the high values of this parameter are observed within the river basins
exposed to the west. In three of the four cases (Barc˘ au, Cri¸ sul Alb and Cri¸ sul Negru)
the average values of the drainage density exceed 1 km/km
2 , while in the case of
Cri¸ sul Repede the value is very close to the unit (Table 16.5).
The values recorded on other basins is below 1 km/km
2 , in the context of a different
orientation, or due to smaller amounts of precipitation within the context of lower
altitude (Middle Some¸ s basin).
The maximum drainage density is reached in Some¸ sul Mic basin, almost
4.3 km/km
2 , developed on a petrographic structure, particularly resistant, of
metamorphic-magmatic type, which prevents ingress of water in underground layers.
Sedimentary rocks, tougher or friable, cover areas that are much smaller compared
to other basins (Mure¸ s basin). In fact, the maximum values of the parameter in all
analyzed collectors reach or exceed 3 km/km
2 , which confirms the term established
in the literature as “water castle” attributed to the Apuseni Mountains.
R. B˘ atina¸ s et al.
The upper basin of Some¸ sul Mic is almost devoid of high permeability rocks due
to its overlapping over the granite platoon of Muntele Mare and over the crystalline
shale in the Gil˘ au Mountains. Only the sedimentary periphery of the Gil˘ au reservoir
area has a sedimentary substrate favorable to underground water infiltration.
The Middle Somes , basin is just the rest of drainage area, deployed at a very
low altimetric level, an area that drains the north-eastern low apophysis of Apuseni
Mountains—the Mese¸ s Mountains.
Its central axis, built of crystalline shale of poor consistency compared to the
Gil˘ au, Vl˘ adeasa massifs, etc., is quasi-impermeable. Its adjacent areas, on the western and eastern slopes, are occupied by sedimentary basins ( ¸
Simleu, with Zal˘ au
micro-depression to the west and Almas , -Agrij to the east). The rocks have a high
permeability and allow the creation of moderate underground water deposits—on
the hearth of the Zal˘ au basin there is even an artesian aquifer.
The Barc˘ au basin is formed on the northern slope of the Plopis , Mountains ( ¸
Ses),
the other low apophysis, situated in the northwest of the Apuseni Mountains.
The only space with some permeability of the component rocks is the rest of the
S , imleu Depression, which partially overlaps the Barc˘ au basin. The entire mountain
area is quasi-impermeable due to the same crystalline shale which is found underground.
16.2.2.2 Drainage Density (Density of the Relief Fragmentation)
As we mentioned at the beginning of this study, in the Apuseni, although we encounter
the most extensive endoreal areas in Romania, the morphometric parameters related
to surface flow are significant. Excepting the karst areas, river network density values
fall within the gap of 0.8–1.2 km/km
2 with local convergence areas, where they
sometimes exceed 1.8 km/km
2 (Câmpeni and Brad depression).
Drainage density, as a result of relief dynamics, records significantly higher values
compared to the density of the permanent network and gives a relevant image on the
surface liquid flow areas. The statistic analysis, from the information presented,
shows that the high values of this parameter are observed within the river basins
exposed to the west. In three of the four cases (Barc˘ au, Cri¸ sul Alb and Cri¸ sul Negru)
the average values of the drainage density exceed 1 km/km
2 , while in the case of
Cri¸ sul Repede the value is very close to the unit (Table 16.5).
The values recorded on other basins is below 1 km/km
2 , in the context of a different
orientation, or due to smaller amounts of precipitation within the context of lower
altitude (Middle Some¸ s basin).
The maximum drainage density is reached in Some¸ sul Mic basin, almost
4.3 km/km
2 , developed on a petrographic structure, particularly resistant, of
metamorphic-magmatic type, which prevents ingress of water in underground layers.
Sedimentary rocks, tougher or friable, cover areas that are much smaller compared
to other basins (Mure¸ s basin). In fact, the maximum values of the parameter in all
analyzed collectors reach or exceed 3 km/km
2 , which confirms the term established
in the literature as “water castle” attributed to the Apuseni Mountains.