The main goal of research presented here is an analysis of nature reserve impact on the performance of the lowland Jeziorsko Reservoir. The Jeziorsko Reservoir is located between sections at km 484+300 and km 503+800 on the Warta River reach. It is multipurpose reservoir working in annual scheme. In 1998 the Nature Reserve "Jeziorsko" was created by Ministry of Environment, Nature Resources and Forestry. The Nature Reserve is located in the upper part of the Jeziorsko Reservoir. Due to that fact one may observe intensive process of sediment accumulation in the upper part of the reservoir. This process is totally free of man's actions, what means it is not disturbed by any hydro-engineering works. In the paper the analysis of vegetation growth and sediment deposition processes is presented. As the result of these processes the water levels in the backwater part of the Jeziorsko Reservoir are significantly are raised, what causes increase of flood risk in the nearby areas. ...
The results of research over influence of air temperature on oxygen condition in carp pond are present in this paper. Mean of dissolved oxygen concentration observed at 8 am were equal 7,18 mg O2·dm-3, at 2 pm – 12,76 mg O2·dm-3 and at 8 pm – 13,37 mg O2·dm-3. Large fluctuations of dissolved oxygen concentration in the euphotic zone of eutrophic fish pond were observed. Oxygen condition lower then lower limit of dissolved oxygen concentration for carp (5 mg O2·dm-3) were observed at 8 am (minimum = 2,34 mg O2·dm-3). The highest oxygen concentration were observed in the afternoon (14 pm) and in the evening (8 pm). The highest oxygen concentration were equal 25,8 mg O2·dm-3. Analysis of connection between air temperature and dissolved oxygen concentration revealed weak but essential relationship for the results from 2 and 8 pm. Increase of oxygen concentration was observed with increase of air temperature. ...
The results of research on influence of insolation on oxygen condition in carp pond are present in this paper. Mean of dissolved oxygen concentration observed at 8 am were equal 7,18 mg O2•dm-3, at 2 pm - 12,23 mg O2•dm-3 and at 8 pm - 12,79 mg O2•dm-3. Large fluctuations of dissolved oxygen concentration in the euphotic zone of eutrophic fish pond were observed. Oxygen condition lower then lower limit of dissolved oxygen concentration for carp (5 mg O2•dm-3) were observed at 8 am (minimum = 2,40 mg O2•dm-3). The highest oxygen concentration were observed in the afternoon (14 pm) and in the evening (8 pm). Analysis of connection between insolation and dissolved oxygen concentration revealed weak but essential relationship for the results at 8 am, 2 pm and 8 pm. Increase of oxygen concentration was observed with increasing of insolation.
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