Zdzisław Michalczyk, Stanisław Chmiel and Marek Turczyński
Lake water stage dynamics in the Łęczna-Włodawa Lake District in 1991-2010
In the years 1991-2010 the water stages of 38 lakes in the Łęczna-Włodawa Lake District were observed. Water stage dynamics of the Łęczna-Włodawa lakes was varied. A multi-annual trend with seasonal water stage variability was clearly observable. Low water stages were observed in the years 1994-1996 and 2004-2005, whereas the highest water stages were reported for 2002 and 2010. The water stages of Lake Piaseczno, the deepest lake, were consistent with solar activity changes. Land improvement works in the Łęczna-Włodawa Lake District and black coal mining caused further local changes in the directions of flow of surface and underground water, as well as modifying the water stage regime of some of the lakes.
Marek Turczyński, Zdzisław Michalczyk, Stanisław Chmiel, Katarzyna Mięsiak-Wójcik and Sławomir Głowacki
Evaluation of the hydrological role of wetlands in the Włodawka River catchment (Polesie Lubelskie)
The Włodawka River catchment of an area of 725 km2 covers the central and eastern part of the Łęczna-Włodawa Lake District. Evaluation of the role of hydrogenic areas in runoff creation was based on materials of the Department of Hydrography and the Institute of Meteorology and Water Management data. The analysis was conducted for selected catchments in which additional hydrometric measurements and water quality tests were done. Such parameters as: the share of hydrogenic surfaces in total catchment area, types of wetlands, their hypsometric location and position with reference to drainage streams were taken into consideration for evaluation. The degree of anthropogenic transformation of the marshland was expressed in terms of density and depth of the drainage ditches that dissect it. It was found that the drained gyttja of Krowie Bagno plays a considerable role in increasing the minimum discharge. Wetlands in the Włodawka River catchment influence the conditions of the runoff and water quality, which is noticeable, primarily, in the concentration of organic carbon, and of nitrogen and phosphorus compounds.