13 Particularities of Drain Liquid in the Small Wetland of Braila …
439
several meanderings and dislocations (Borcea, Caragheorghe, Cremenea, Macin),
thus delimiting two major islands, Balta Ialomitei (Borcei) and Balta Brailei (Balta—
stagnant water, not very deep, with specific vegetation and fauna, especially encountered in the floodplain area) [22, 25, 28, 29].
The researched area is located on the western side of the former Balti of Brailei,
which in the past had an area of approximately 96,000 ha, being bounded to the west
by the Danube and to the east by the Macin channel (Dunarea Veche) (Fig. 13.1). The
size of this area is approximately 60 km long and has a maximum width of 23 km.
This wet area, due to its extensive area, was able to pick up large volumes of water
when the high floods of spring floods reached a high level and retained some of the
water even during periods of drought in numerous lakes (ponds) [30].
The water scarcity of these lakes was estimated at over 16,000 ha. The embankment works, made to restrict this wetland to obtain farmland between 1964 and
1970, removed the natural flow of the river and natural regulation of the maximum
flow and volumes of water transited on the lower course of the Danube surface over
72,000 ha. Thus, the current enclosure of the Big Island of Brailei, bounded to the east
by the Macin channel and west of the Valciu channel (km 236–196). The Danube
(km 196–185 and km 175–169) and the Cravia channel (km 185 at 175), as well
as the dirty agricultural areas on the left bank of the river, along the line of Gura
Calmatui—Stanca—Stancuta—Gropeni—Tichilesti—Chiscani localities.
In the area of the Small Island of Braila, there is a low plain, formed during
Holocene, which has altitudes between 8 and 12 m. Exceptions to this rule are the
elevations from Blasova (45.2 m) and Piatra Fetei, which are in fact high local blocks
(island remnants) of North Dobrogea, remain as erosion witnesses over the holocene
alluvium of the plain [24].
The geological analysis shows a succession of alluvial deposits, placed in the
semipermeable complex from the surface, up to 10–15 m depth (often with clay),
where the groundwater is cantonal, and under it there are depth aquifers, consisting
of fine sands up to 25–30 m and then coarse sands and gravels up to 90–100 m.
On highly permeable alluvial deposits, with thicknesses of 60–100 m, due to the
processes of pedogenesis, young soils, alluvial type, affected by gleizing processes,
with particularly high fertility.
Along with this flat and smooth alluvial plain, the river’s rich network produces
numerous bifurcations of channels and confluences, which close the islands with
variable dimensions. Outside the active channels currently, on the surface of the
alluvial plains, there are the traces of many abandoned channels of the river, also
known as the privy. There are also many canals, lakes, ponds, and marshes along
with erosion beams and witnesses such as river island or hillocks.
The lakes in the Braila small wetlands that were left behind after large land
improvements appear mostly in the southern part, on a surface of 3500 ha. The
largest lakes are Festile, Vulpasu, Sbenghiosu, Beghiu, Sinetele, Balaia, Gasca, Jigna,
Rotundu, Manole, Cojoacele Mari, Catinul lui Mos Ion, Catinul cu ventrice, Rastina,
Cortinele. All over the world, flow regulation of large rivers has been carried out by the
construction of dams, dykes, channelization or floodplain reclamation [12, 31–33].
439
several meanderings and dislocations (Borcea, Caragheorghe, Cremenea, Macin),
thus delimiting two major islands, Balta Ialomitei (Borcei) and Balta Brailei (Balta—
stagnant water, not very deep, with specific vegetation and fauna, especially encountered in the floodplain area) [22, 25, 28, 29].
The researched area is located on the western side of the former Balti of Brailei,
which in the past had an area of approximately 96,000 ha, being bounded to the west
by the Danube and to the east by the Macin channel (Dunarea Veche) (Fig. 13.1). The
size of this area is approximately 60 km long and has a maximum width of 23 km.
This wet area, due to its extensive area, was able to pick up large volumes of water
when the high floods of spring floods reached a high level and retained some of the
water even during periods of drought in numerous lakes (ponds) [30].
The water scarcity of these lakes was estimated at over 16,000 ha. The embankment works, made to restrict this wetland to obtain farmland between 1964 and
1970, removed the natural flow of the river and natural regulation of the maximum
flow and volumes of water transited on the lower course of the Danube surface over
72,000 ha. Thus, the current enclosure of the Big Island of Brailei, bounded to the east
by the Macin channel and west of the Valciu channel (km 236–196). The Danube
(km 196–185 and km 175–169) and the Cravia channel (km 185 at 175), as well
as the dirty agricultural areas on the left bank of the river, along the line of Gura
Calmatui—Stanca—Stancuta—Gropeni—Tichilesti—Chiscani localities.
In the area of the Small Island of Braila, there is a low plain, formed during
Holocene, which has altitudes between 8 and 12 m. Exceptions to this rule are the
elevations from Blasova (45.2 m) and Piatra Fetei, which are in fact high local blocks
(island remnants) of North Dobrogea, remain as erosion witnesses over the holocene
alluvium of the plain [24].
The geological analysis shows a succession of alluvial deposits, placed in the
semipermeable complex from the surface, up to 10–15 m depth (often with clay),
where the groundwater is cantonal, and under it there are depth aquifers, consisting
of fine sands up to 25–30 m and then coarse sands and gravels up to 90–100 m.
On highly permeable alluvial deposits, with thicknesses of 60–100 m, due to the
processes of pedogenesis, young soils, alluvial type, affected by gleizing processes,
with particularly high fertility.
Along with this flat and smooth alluvial plain, the river’s rich network produces
numerous bifurcations of channels and confluences, which close the islands with
variable dimensions. Outside the active channels currently, on the surface of the
alluvial plains, there are the traces of many abandoned channels of the river, also
known as the privy. There are also many canals, lakes, ponds, and marshes along
with erosion beams and witnesses such as river island or hillocks.
The lakes in the Braila small wetlands that were left behind after large land
improvements appear mostly in the southern part, on a surface of 3500 ha. The
largest lakes are Festile, Vulpasu, Sbenghiosu, Beghiu, Sinetele, Balaia, Gasca, Jigna,
Rotundu, Manole, Cojoacele Mari, Catinul lui Mos Ion, Catinul cu ventrice, Rastina,
Cortinele. All over the world, flow regulation of large rivers has been carried out by the
construction of dams, dykes, channelization or floodplain reclamation [12, 31–33].