254
C. Trifanov et al.
The water quality has slightly improved due to both the diminution of agricultural
and industrial pollution and to the measures imposed on economic agents by the
local EPA. The watercourses length from first-class quality increased from 35%
(year 1985) to 66% (year 2002). Nevertheless, 6.6% of the monitored rivers do not
meet the quality standards which are an important component in the sustainable
development of the aquatic fauna. At the same time, there are no statistics related to
the efficiency of water use in industry, although there is a water recycling system that
indicates values ranging from 10% to 95% depending on the type of industry and
factories. In agricultural activities, a large amount of water is allocated to irrigations,
where the efficiency of the water use ranges from 60 to 80%. The average specific
water consumption per inhabitant per day in the urban area at country level is about
513 L out of which: domestic use—294 L; public use—70 L; economic activities
use—122 L; network losses—134 L. In the rural areas, where the specific water
consumption is over 150 L, there is a real concern for the water losses reduction. At
national level, the water losses will decrease from 34%, value recorded in the present
time, to 15% in 2020. If the real water costs would be introduced and applied, this
would represent a good incentive for the economic agents to reduce the losses in
water supply and increase the recirculation and water reuse. The most significant
matters include the low level of investments and ineffective application of reforms
in the national economy [31].
The agricultural industry is the main source of water pollution with methane
(CH 4 ) from animal farms, nitrogen dioxide (NO 2 ) and ammonia (NH 3 ), the last one
exceeding 95% from total. This is the reason why the water pollution in the upstream
area of the Danube floodplain is increasing. The structure, function and dynamics of
animal communities have always been strictly dependent on the Danube’s hydrology
and hydrochemistry, as well as on its interaction with human activities. The floodplain of the Lower Danube it is acknowledged as the whole phenomena the Danube
assembled through alluvial processes to the direct action of its waters developed
upstream from Calarasi to Balta Borcea and Balta Braila [33–37].
The marshes of the Danube are generated by the action of two or more arms, in
which the meaning of sedimentation processes, whether done directly or through
flooding is directed from the periphery to the interior. During the last century, the
floodplain of the Danube, the Romanian side, was mostly embanked, the ecosystems
of this wetland being altered and largely desiccated for agricultural purpose. The river
dynamics can no longer maintain or enlarge the wetland ecosystems, the embanked
sections of the floodplain tend towards ruderal areas understood as a phenomenon
of changing the wetland ecosystem into terrestrial ecosystem under anthropogenic
impact [38–50].
The general features of the floodplain relief are a direct result of the intensity of
floods (seasonal or peaks), which is understood both in terms of frequency, amplitude
and duration. The complexity of the geological base, its mobility and the particularities of the geomorphological evolution of the region, explain the very complicated
course of the Danube with many changes of direction, large loops and meanders. The
erosion, transport and sedimentation occur simultaneously on the entire riverbed
by the continuous tendency of formation or enlarging of the alluvial islands. The
C. Trifanov et al.
The water quality has slightly improved due to both the diminution of agricultural
and industrial pollution and to the measures imposed on economic agents by the
local EPA. The watercourses length from first-class quality increased from 35%
(year 1985) to 66% (year 2002). Nevertheless, 6.6% of the monitored rivers do not
meet the quality standards which are an important component in the sustainable
development of the aquatic fauna. At the same time, there are no statistics related to
the efficiency of water use in industry, although there is a water recycling system that
indicates values ranging from 10% to 95% depending on the type of industry and
factories. In agricultural activities, a large amount of water is allocated to irrigations,
where the efficiency of the water use ranges from 60 to 80%. The average specific
water consumption per inhabitant per day in the urban area at country level is about
513 L out of which: domestic use—294 L; public use—70 L; economic activities
use—122 L; network losses—134 L. In the rural areas, where the specific water
consumption is over 150 L, there is a real concern for the water losses reduction. At
national level, the water losses will decrease from 34%, value recorded in the present
time, to 15% in 2020. If the real water costs would be introduced and applied, this
would represent a good incentive for the economic agents to reduce the losses in
water supply and increase the recirculation and water reuse. The most significant
matters include the low level of investments and ineffective application of reforms
in the national economy [31].
The agricultural industry is the main source of water pollution with methane
(CH 4 ) from animal farms, nitrogen dioxide (NO 2 ) and ammonia (NH 3 ), the last one
exceeding 95% from total. This is the reason why the water pollution in the upstream
area of the Danube floodplain is increasing. The structure, function and dynamics of
animal communities have always been strictly dependent on the Danube’s hydrology
and hydrochemistry, as well as on its interaction with human activities. The floodplain of the Lower Danube it is acknowledged as the whole phenomena the Danube
assembled through alluvial processes to the direct action of its waters developed
upstream from Calarasi to Balta Borcea and Balta Braila [33–37].
The marshes of the Danube are generated by the action of two or more arms, in
which the meaning of sedimentation processes, whether done directly or through
flooding is directed from the periphery to the interior. During the last century, the
floodplain of the Danube, the Romanian side, was mostly embanked, the ecosystems
of this wetland being altered and largely desiccated for agricultural purpose. The river
dynamics can no longer maintain or enlarge the wetland ecosystems, the embanked
sections of the floodplain tend towards ruderal areas understood as a phenomenon
of changing the wetland ecosystem into terrestrial ecosystem under anthropogenic
impact [38–50].
The general features of the floodplain relief are a direct result of the intensity of
floods (seasonal or peaks), which is understood both in terms of frequency, amplitude
and duration. The complexity of the geological base, its mobility and the particularities of the geomorphological evolution of the region, explain the very complicated
course of the Danube with many changes of direction, large loops and meanders. The
erosion, transport and sedimentation occur simultaneously on the entire riverbed
by the continuous tendency of formation or enlarging of the alluvial islands. The