8 Romanian Danube River Floodplain …
271
8.4 The Consequences of Changing the Hydrological
Conditions
Objectives pursued:
• Reconsideration of economic activities within the embanked polders according to
the cost/benefit ratio for investments for the maintenance of the defense dykes and
the other existing hydro-technical constructions;
• Establishment of a controlled flood regime for storing water at maximum levels
of the Danube which endangers the defense systems;
• The establishment of the flood regime and the retention of water in the embanked
polders obtained through drainage procedure of the former lakes Bistret, Potelu,
Suhaia, Greaca, Calarasi, etc., to renature them.
The recent reduction of wetlands is mainly due to the development of agriculture
through the embankment. This reduction also occurs by draining some surfaces, or
by regulating some watercourses.
There are many mechanisms through which human activity influences the stability of a wetland, such as deliberate intervention by improving drainage to expand
agricultural land or through peat exploitation. This type of intervention has attracted
the attention of public opinion, especially through the mass media of the danger of
loss of habitats for many species that depend on the existence of these areas.
In the case of the Danube floodplain, the change of the hydrological conditions
had the following consequences:
• unproductive lands and the increase of soil salinity;
• reduction of water exchange with the surrounding areas;
• habitat loss for birds;
• major changes in the structure and composition of the vegetation;
• discontinuation of the fish movement from nearby areas towards the polder where
they had optimal conditions for spawning;
• loss of organic matter through mineralization;
• blocking the filtration role of the sediments and nutrients gained through floods.
Thus, under these circumstances, the best option is the use of strict wetland policies
in the Lower Danube floodplain, followed by a well-developed alert monitoring
system as well as many advanced tools to explore strategies and policies to address
to the detected threats. With the increased effort on the system and the complexity
of the problems, the need for planning tools is changing rapidly.
8.5 Conclusions
Assessment of the socio-economic systems way of function within the socioecological complexes of the lower Danube floodplain as well as their performance
271
8.4 The Consequences of Changing the Hydrological
Conditions
Objectives pursued:
• Reconsideration of economic activities within the embanked polders according to
the cost/benefit ratio for investments for the maintenance of the defense dykes and
the other existing hydro-technical constructions;
• Establishment of a controlled flood regime for storing water at maximum levels
of the Danube which endangers the defense systems;
• The establishment of the flood regime and the retention of water in the embanked
polders obtained through drainage procedure of the former lakes Bistret, Potelu,
Suhaia, Greaca, Calarasi, etc., to renature them.
The recent reduction of wetlands is mainly due to the development of agriculture
through the embankment. This reduction also occurs by draining some surfaces, or
by regulating some watercourses.
There are many mechanisms through which human activity influences the stability of a wetland, such as deliberate intervention by improving drainage to expand
agricultural land or through peat exploitation. This type of intervention has attracted
the attention of public opinion, especially through the mass media of the danger of
loss of habitats for many species that depend on the existence of these areas.
In the case of the Danube floodplain, the change of the hydrological conditions
had the following consequences:
• unproductive lands and the increase of soil salinity;
• reduction of water exchange with the surrounding areas;
• habitat loss for birds;
• major changes in the structure and composition of the vegetation;
• discontinuation of the fish movement from nearby areas towards the polder where
they had optimal conditions for spawning;
• loss of organic matter through mineralization;
• blocking the filtration role of the sediments and nutrients gained through floods.
Thus, under these circumstances, the best option is the use of strict wetland policies
in the Lower Danube floodplain, followed by a well-developed alert monitoring
system as well as many advanced tools to explore strategies and policies to address
to the detected threats. With the increased effort on the system and the complexity
of the problems, the need for planning tools is changing rapidly.
8.5 Conclusions
Assessment of the socio-economic systems way of function within the socioecological complexes of the lower Danube floodplain as well as their performance