Title:

The water balance in a dam Reservoir – a case study of the Przebędowo reservoir

Creator:

Waligórski, Błażej ; Korytowski, Mariusz ; Zydroń, Adam ; Liberacki, Daniel ; Fiedler, Michał ; Stasik, Rafał

Subject:

small-scale water retention ; dammed reservoirs ; water balances

Description:

This study presents the results of investigations conducted in the hydrological years of 2017 and 2018 in the immediate catchment of the Przebędowo reservoir, located in the Wielkopolskie province 25 km north of Poznań in the Murowana Goślina commune. The immediate catchment of the reservoir is approx. 95 km2 in area, while the direct recharge area of the lake (immediate catchment) covers 1.31 km2. The areas adjacent to the reservoir are arable lands composed of fluvial Quaternary (Pleistocene) deposits, while the analysis of layers covered by piezometers showed a predominance of medium sands deposited to a depth of approx. 3 m. The analysed reservoir was constructed in the valley of the Trojanki river (from 6+915 km to 8+371 km of its course) by the Wielkopolska Land Reclamation and Hydraulic Structure Authority in Poznań and it was commissioned in November 2014. The embankment dam of the reservoir is class IV, it is 334 m in length and 3.30 m in height. The reservoir of 1450 m in length and maximum width of 120 m, at the normal pool elevation of 72.50 m a.s.l. has a mean depth of 0.94 m and the pool area of 12.03 ha. The shoreline length of the reservoir is 2980 m, shoreline density is 248 m×ha-1 and the elongation index is 12. In turn, the flood control capacity derived from the difference between normal and maximum pool level is around 67 000 m3.The conducted analyses confirmed that apart from the weather conditions such as precipitation, air temperatures and evaporation from the reservoir a considerable role for the fluctuations in water levels in the reservoir was played by the anthropogenic factor. It was particularly related with the manner of reservoir operation frequently characteristic to dammed reservoirs and with the artificial control of water circulation.Analysis of the water balance for the Przebędowo reservoir showed that in the winter half-years of the analysed hydrological years of 2017 and 2018 the dominant factor in the case of increments was connected with inflow to the reservoir in the Trojanka water­course, amounting to 12.9 hm3 and 5.16 hm3, respectively. To a much lesser extent the increments of water in those half-years were determined by the inflow to the reservoir from adjacent areas and by precipitation. In the case of losses the greatest share in the water balance was observed in the discussed half-years for outflow from the reservoir through the watercourse, which amounted to 10.0 hm3 and 3.75 hm3. To a lesser extent losses were determined by the uncontrolled underground outflow and subsurface inflow to the reservoir from adjacent areas. In turn, evaporation from the reservoir surface and water storage losses determined losses only slightly. Whereas in the summer half-years the increments in the water balance to the greatest extent were determined by inflows to the reservoir through the watercourse, which amounted to 10.7 hm3 (2017) and 3.59 hm3 (2018), while in the case of losses it was outflows from the reservoir amounting to 9.06 hm3 and 2.7 hm3. In turn, a lesser role was played in the case of losses by outflow from the reservoir to adjacent areas, which in the discussed half-years was comparable and amounted to a mean 0.66 hm3.

Place of publishing:

Koszalin

Publisher:

Politechnika Koszalińska

Date:

2020

Type:

artykuł w czasopiśmie

Format:

application/pdf

Language:

eng

Is part of:

Rocznik Ochrona Środowiska. Vol. 22, s. 324-346

Rights:

Biblioteka Politechniki Koszalińskiej

Access rights:

internet

License:

Creative Commons BY-SA 4.0