TY - JOUR TI - Zmiany powierzchni i batymetrii wybranych jezior Pojezierza Pomorskiego AU - Ptak, Mariusz TI - Zmiany powierzchni i batymetrii wybranych jezior Pojezierza Pomorskiego AB - The work presents bathymetric changes and changes of area of 67 lakes located within the Pomeranian Lake District in northern Poland. On the basis of bathymetric plans and topographic maps, an analysis was carried out focused on changes in bathymetry and area lakes within a period of over 60 years. The total area of the first group of lakes diminished by 5.4% and the volume of lake basins – by 13.1%. The fact that the change in volume is higher than the change in area, which was observed, clearly demonstrates that the decline of natural water reservoirs is caused not only by the shrinking coastline, but also by the phenomenon of shallowing of lake basins. The decrease in the volume of lake basins also negatively affects the lakes’ natural resistance to degradation. Moreover, the changes in the total area of all lakes throughout the 20 th century were also analyzed and it was found that the total area diminished by 8.0%. VL - 2013 IS - Zeszyt 133 PY - 2013 SN - 1644-3586 C1 - 2083-3113 SP - 61 EP - 76 DO - 10.4467/20833113PG.13.011.1101 UR - https://ejournals.eu/czasopismo/prace-geograficzne/artykul/zmiany-powierzchni-i-batymetrii-wybranych-jezior-pojezierza-pomorskiego KW - bathymetry KW - lake diseaperance KW - water resources