The aim of this paper was to present the possibility of integrating LIDAR data with bathymetric measurements in order to assess the changes in water resources and morphometric parameters. The area of study was Lake Kiedrowickie (Poland). A change in most of the morphometric parameters has been observed. Especially important was the drop in water resources which amounted to more than 30%. A significant decrease (13.4%) was also observed in case of the lake surface. In conclusion we state that the integration of valid bathymetric measurements with the LIDAR data gives the full capability to model the changes of lake morphometric parameters with unprecedented accuracy. A significant complementarity and synergy of applying both techniques has been stressed.
Mieczysław Kunz, Rajmund Skowron and Szymon Skowroński
Morphometry changes of Lake Ostrowskie (the Gniezno Lakeland) on the basis of cartographic, remote sensing and geodetic surveying
The authors studied changes in the morphometry of Lake Ostrowskie over the period of 123 years on the grounds of cartographic materials, remote sensing data, land surveying, and data referring to the water stages. The changes that occurred in the lake up to the 1960s were related to the regulation and melioration works conducted in the entire area of the Gniezno Lakeland. On the other hand, drainage of the open pits of brown coal resulted in the considerable decline of the water table by another 2.5 m in the years 2002-2009. As a result of the decline of water down to 96.4 m a.s.l. the present lake was divided into two water bodies (the eastern one and the western one) joint with a channel. This led to the decline in the lake area from 346.7 ha in 1887 to 242.0 ha, and its volume by 28.9%, out of which by 18.3% only in recent twenty-eight years.
The article presents the results of landscape analysis of the surroundings of Lake Rzecin in Noteć Forest depicted on cartographic materials. Morphometrical analysis and analysis of changes in the water conditions of Lake Rzecin were conducted. Thanks to many cartographic data, changes in lake geometry could be observed during almost the whole of the last two centuries. The results show that the major impact on the rate of lake level decrease in the last two hundred years was due to melioration works. Two periods of rapid decrease in the lake surface can be observed during this time. The first occurred as a result of the creation of Rzecin Ditch, which probably took place in the middle of the 19th century; the second, in all likelihood, with its cleaning out; the exact date of this operation is not known but the results of map analysis suggest that it could have happened between 1958 and 1966. Due to these two events the lake surface decreased by 73.6% during the analysed period. Apart from this phenomenon the lake surface area seems to be quite stable: there were some fluctuations; however, changes did not exceed more than 5%. That is why it can be assumed that the human factor has the biggest influence on succession rate of the lake ecosystem. Analysis of the map collection shows that during the last two centuries there were no huge changes in the local landscape; however, other historical sources do not confirm this. According to them, not only man but also fires and insect gradations had an enormous influence on the Noteć Forest ecosystem. Nonetheless, land use structure within the Rzecin Ditch catchment area did not change a great deal; the most significant modification was the increment of forested areas from 74.1 up to 85.1 %.
The paper presents the changes that have occurred in the morphometry of Lakes Gopło and Ostrowskie, which are located
in central Poland. The analysis covered the period characterised by increased human interference into the water cycle, which has
been taking place continually since the mid-eighteenth century. On the basis of available cartographic materials (aerial photographs,
topographic maps, bathymetric charts of the lakes) and the authors’ own field measurements digital terrain models were developed
for the immediate environment of the surveyed lakes. These models, in turn, were used for measuring basic parameters characterising
the external dimensions of the lakes (surface area, length and maximum width, shoreline length) and their underwater relief (volume,
maximum and average depth). In addition, the selected indicators of the shape and form of the lake basins were determined. The results
showed a drastic reduction of water resources of the two lakes. The basin of Lake Gopło covers only the deepest parts of the former
reservoir, accounting for only 23.3% of the lake before 1772, and 32.5% of its former volume. In the case of Lake Ostrowskie the surface
area and volume decreased, respectively, by 23.5% (74.9 ha) and 21.3% (6 695 000 m3). Such large changes in surface area and volume of
both lakes have contributed to significant changes in other morphometric parameters and indicators. In particular, significant changes
were observed in relation to such morphometric characteristics as length and maximum width, as well as average and maximum depth.
The spatial variation of water transparency of the largest Polish lakes was presented on the basis of documentary material collected by the Voivodeship Inspectorates for Environment Protection as well as university geography departments in the period of 1991-2013. Seasonal results of the Secchi disc measurements (spring, summer) for 706 lakes were gathered. This is more than 68% of the total number of Polish lakes with a surface area larger than 50 ha. The mean water transparency of these lakes was 1.87 m, while the median was 1.58 m. Distinct inter-regional differences of the Secchi disc transparency were found, and it was also possible to distinguish three relatively homogeneous groups of macroregions where lakes have different optical characteristics. They can be divided into areas with lakes with high (3.05 m), medium (1.99-2.11 m) and low (1.22-1.52 m) water transparency. The Secchi disc transparency of these lakes was also analysed in relation to concentration values of the main forms of the optically significant constituents of water (coloured dissolved organic matter, suspended matter). The mean transparency of turbid, stained and clear lakes was, respectively, 1.16, 2.02, and 2.92 m. Moreover, regional empirical models to predict Secchi disc transparency from chlorophyll a concentration were also developed. It was assumed that inter-regional differences between models could be due to the probably different time of the ice sheet recession. The influence of the lake morphometry was most fully reflected in the impact of the depth conditions.
Dissolved oxygen in water (DO) is one of the primary parameters determining its quality. It remains in close relation to water temperature. The article presents results of DO and water temperature measurements performed for five stratified lakes in Poland in the years 2007-2014. The measurements were performed with monthly frequency in the summer half-year (May-October) in the deepest place of each of the lakes. The compared data show the complex character of the course of both of the parameters. The analysis of depth profiles revealed the prevalence of a decreasing tendency, or no tendency was recorded - both in the case of DO and water temperature. Due to the incoherent character of the water in the case of stratified lakes, a more detailed comparison was performed, referring to changes occurring in zones developed during summer stratification. It was determined that the temperature of the epilimnion was directly dependent on air temperature, and in all cases it showed an increasing tendency. Simultaneously, along with an increase in temperature, in the majority of cases, DO concentration in the zone decreased. In reference to the waters of the hypolimnion, increasing, decreasing, and no tendencies were recorded. The above distribution is determined by individual factors of the lakes - morphometry, trophic status, groundwater alimentation, etc. Several years of measurements of DO and water temperature in depth profiles of several lakes in Poland constitute valuable information on the current transformations of the environment of this part of Europe. In the future, the information can provide the basis for long-term analyses over the next decades, enriching global knowledge on those parameters of key importance for water ecosystems.
Jolanta Ejsmont-Karabin, Andrzej Górniak and Maciej Karpowicz
.H., Bakkestuen V., Walseng B., 2006, Extrinsic and intrinsic controls of zooplankton diversity in lakes, Ecology 87(2): 433–443.
Karpowicz M., Górniak A., Więcko A., Cudowski A., 2016, The variability of summer phytoplankton communities in different types of lakes in Suwałki Landscape Park, Limnol. Rev. 16(4): 229–236.
Keller W., Conlon M., 1994, Crustacean Zooplankton Communities and LakeMorphometry in Precambrian Shield Lakes, Can. J. Fish. Aquat. Sci. 51(11): 2424–2434.
Leibold M.A., 1999, Biodiversity and nutrient enrichment in pond plankton communities
Dariusz Borowiak, Kamil Nowiński and Katarzyna Grabowska
Blais J.M., Kalff J., 1995, The influence of lakemorphometry on sediment focusing, Limnol. Oceanogr. 40(3): 582–588.
Borowiak D., 2011, Właściwości optyczne wód jeziornych pomorza (Optical properties of the Pomeranian lakes), Wydaw. UG, Gdańsk, 275 pp. (in Polish, English summary).
Byczkowski A., 1980, Bilans wodny jeziora położonego w obszarze źródliskowym zlewni, na przykładzie jeziora Jaczno na Pojezierzu Suwalskim (Water balance of a lake situated in a headwater catchment. A case study of Lake Jaczno in Suwałki Lakeland), [in:] Friedrich M. (ed
Ławniczak A. E., Choiński A., Kurzyca I., 2011, Dynamics of lakemorphometry and bathymetry in various hydrological conditions, Pol. J. Environ. Stud. (in press).
Majdanowski S., 1954, Jeziora Polski (The lakes of Poland), Prz. Geogr. 26(2): 17-50 (in Polish, English summary).
Mikulski Z., 1966, Zarys hydrografii Polski (Outline of the hydrography of Poland), PWN, Warszawa, p. 288 (in Polish).
Müller B., Lotter A. F., Sturm M., Ammann A., 1998, Influence of catchment quality and altitude on the
podstawa oceny dostawy materii biogennej do jezior (Effect of the physical geographic environment on the biogenus matter delivery to the lakes), Pr. Stud. Geogr. UW 7: 65-88 (in Polish).
Bajkiewicz-Grabowska E., 2008, Lake geoecosystem as an indicator of the rate of natural eutrophication of water reservoirs, Limnol. Rev. 8(1-2): 9-12.
Carlson R. F., 1977, A trophic index for lakes, Limnol. Oceanogr. 22(2): 361-369.
Fee E. J., 1979, A relation between lakemorphometry and primary productivity