scholarly journals Water Surface Overgrowing of the Tatra’s Lakes

2018 ◽  
Vol 37 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Juraj Kapusta ◽  
Juraj Hreško ◽  
František Petrovič ◽  
Dávid Tomko-Králo ◽  
Jozef Gallik
Keyword(s):  
Water Surface ◽  
Open Water ◽  
Rapid Expansion ◽  
Peat Bogs ◽  
Vegetation Zone ◽  
Fine Sediments ◽  
Significant Phenomenon ◽  
The High Tatras ◽  
Alpine Landscape ◽  
Lake Basins

AbstractTatra’s lakes are vulnerable ecosystems and an important element of the alpine landscape. Mainly some shallow lake basins succumb to intense detritus sedimentation, fine fractions of material from the catchment area or to the overgrowing of water level by vegetation. In this paper, changes and dynamics of the 12 Tatra’s lake shorelines that were selected based on the detailed mapping of their extent are pointed out. Changes were assessed by accurate comparisons of historical and current orthophoto maps from the years 1949, 1955 and 2015 – and therefore, based on the oldest and the latest relevant materials. Due to the overgrowing of lakes caused by vegetation, their water surface decreased from −0.9% up to −47.9%, during the examined period. Losses were caused by the overgrowing of open water surface by the communities of sedges and peat bogs. The most significant dynamics of the shorelines during the last decades were reached by those lakes, into which fine sediments were simultaneously deposited by means of mountain water coarse. These sediments made the marginal parts of the lake basins shallower and accelerated rapid expansion of vegetation to the detriment of the open water surface. The overgrowing of shallow moraine lakes lying in the vegetation zone is a significant phenomenon of the High Tatras alpine landscape. It leads to their gradual extinction, turn into peat bogs and wet alpine meadows.

Present-day evolution of coastal lakes based on the example of Jamno and Bukowo (the Southern Baltic coast)

2014 ◽  
Vol 43 (2) ◽  
Author(s):  
Adam Choiński ◽  
Mariusz Ptak ◽  
Agnieszka Strzelczak
Keyword(s):  
Water Surface ◽  
Open Water ◽  
Aerial Photographs ◽  
Direct Connection ◽  
The Baltic Sea ◽  
Coastal Lakes ◽  
Baltic Coast ◽  
Water Surface Area ◽  
The Baltic ◽  
Lake Basins

AbstractThis study presents the directions and the rate of changes occurring in the coastal lakes Jamno and Bukowo, located in northern Poland. Based on the cartographic materials and aerial photographs of those water bodies, it was established that in 1909–2012, the area of the lakes decreased by 183.6 ha (7.7%) and 250.7 ha (13.6%) for Jamno and Bukowo, respectively. Another component of lake disappearance — shallowing of lake basins — was analyzed using bathymetric plans. It turned out that water supplies of Jamno during more than 100 years decreased by 2.4 million m3 (5.9%), while in the case of Bukowo, it was 5.9 million (17.5%). Unfavorable location (inflow of pollutants from the basin) and morphometry of both lakes should be considered as the main causes of such major changes. The lakes are polymictic with a considerable area of the shallowest zone (1 m depth). This favors the vegetation succession and, consequently, shallowing of the lake basins. Moreover, direct connection with the Baltic Sea contributes to the fact that the materials of marine origin deposited in the form of a reverse delta also contribute to a decrease in the open water surface area.

scholarly journals Modeling the Impacts of Urbanization and Open Water Surface on Heavy Convective Rainfall: A Case Study over the Emerging Xiong'an City, China

2019 ◽  
Vol 124 (16) ◽  
pp. 9078-9098 ◽  
Author(s):  
Yue Xing ◽  
Guangheng Ni ◽  
Long Yang ◽  
Yan Yang ◽  
Pei Xing ◽  
...  
Keyword(s):  
Water Surface ◽  
Open Water ◽  
Convective Rainfall

scholarly journals Methane Content and Emission in the Permafrost Landscapes of Western Yamal, Russian Arctic

Geosciences ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 412
Author(s):  
Gleb E. Oblogov ◽  
Alexander A. Vasiliev ◽  
Irina D. Streletskaya ◽  
Natalia A. Zadorozhnaya ◽  
Anna O. Kuznetsova ◽  
...  
Keyword(s):  
Active Layer ◽  
Methane Content ◽  
Yamal Peninsula ◽  
Peat Bogs ◽  
Western Coast ◽  
Permafrost Degradation ◽  
Russian Arctic ◽  
Landscape Map ◽  
The Yamal Peninsula ◽  
Lake Basins

We present the results of studies of the methane content in soils of the active layer and underlying permafrost, as well as data on the emission of methane into the atmosphere in the dominant landscapes of typical tundra of the western coast of the Yamal Peninsula. A detailed landscape map of the study area was compiled, the dominant types of landscapes were determined, and vegetation cover was described. We determined that a high methane content is characteristic of the wet landscapes: peat bogs within the floodplains, water tracks, and lake basins. Average values of the methane content in the active layer for such landscapes varied from 2.4 to 3.5 mL (CH4)/kg, with a maximum of 9.0 mL (CH4)/kg. The distribution of methane in studied sections is characterized by an increase in its concentration with depth. This confirms the diffuse mechanism of methane transport in the active layer and emission of methane into the atmosphere. The transition zone of the upper permafrost contains 2.5–5-times more methane than the active layer and may become a significant source of methane during the anticipated permafrost degradation. Significant fluxes of methane into the atmosphere of 2.6 mg (CH4) * m−2 * h−1 are characteristic of the flooded landscapes of peat bogs, water tracks, and lake basins, which occupy approximately 45% of the typical tundra area.

scholarly journals Comparison of SEBS and SEBAL Algorithms in Evaporation Estimation from Open Water Surface with the Assessment of the Salinity Effect

2019 ◽  
Vol 22 (4) ◽  
pp. 317-329
Author(s):  
R. Ziaee ◽  
M. Moghaddasi ◽  
S. Paimozd ◽  
M. H. Bagher ◽  
◽  
...  
Keyword(s):  
Water Surface ◽  
Open Water ◽  
Salinity Effect

Impact of habitat heterogeneity on the biodiversity and density of the zooplankton community in shallow wetlands (Upo wetlands, South Korea)

2016 ◽  
Vol 45 (4) ◽  
Author(s):  
Jong-Yun Choi ◽  
Kwang-Seuk Jeong ◽  
Seong-Ki Kim ◽  
Gea-Jae Joo
Keyword(s):  
South Korea ◽  
Zooplankton Community ◽  
Open Water ◽  
Structural Heterogeneity ◽  
Taxonomic Composition ◽  
Zooplankton Biomass ◽  
Freshwater Ecosystems ◽  
Habitat Types ◽  
Vegetation Zone ◽  
Zooplankton Density

AbstractMacrophytes play a major role in the structuring of aquatic environments, and create diverse microhabitats. Therefore, these plants represent an important factor regulating the zooplankton biomass, taxonomic composition, and distribution in freshwater ecosystems. In the current study, we examined the effects of the structural heterogeneity provided by various macrophytes. We identified four habitat types in this study: (1) open water (without macrophytes), (2) the helophyte zone, (3) the pleustophyte zone, and (4) the mixed vegetation zone (containing pleustophytes, nymphaeids, and elodeids). We tested the hypothesis that complex habitat structures support large zooplankton assemblages. Specifically, we collected zooplankton samples from a total of 119 sampling points in the Upo Wetlands, South Korea, during the spring and autumn of 2009. The largest zooplankton assemblage was found in the mixed macrophyte zone, followed by the helophyte and pleustophyte zones. The pleustophyte zone supported larger zooplankton assemblages during autumn compared to spring. Differences in zooplankton assemblages were considered to be strongly related to seasonal variation in the development and growth of pleustophytes. However, two-way ANOVA revealed that seasons had no significant influence on the zooplankton density and diversity. Instead, different habitat types substantially determined zooplankton characteristics. In conclusion, we demonstrated that wetland areas with high macrophyte species diversity contribute toward higher zooplankton diversity.

Effects of ice on the hydraulics of Mackenzie River at the outlet of Great Slave Lake, N.W.T.: a case study

1995 ◽  
Vol 22 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Faye Hicks ◽  
Xiaobing Chen ◽  
David Andres
Keyword(s):  
Water Surface ◽  
Open Water ◽  
Ice Cover ◽  
Late Winter ◽  
Ice Breakup ◽  
Great Slave Lake ◽  
Surface Profiles ◽  
Bed Roughness ◽  
Discharge Measurements ◽  
Mackenzie River

The effects of ice on the conveyance characteristics of the Mackenzie River at the outlet of Great Slave Lake are modeled on the basis of cross section surveys, discharge measurements, and water surface profiles taken during open water and ice covered conditions. The calibrated bed roughness values, expressed in terms of Mannings n, range from 0.020 to 0.030. Based on measured ice thicknesses ranging from 0.6 to 1.2 m in the study reach upstream of Providence Narrows, the calibrated roughness of the 1992 late winter ice cover is 0.015. Discharge estimates, based on this late winter ice cover calibration, measured water surface profiles, and documentation of major ice movements during April and May of 1992, show relatively good agreement with the discharge measurements taken at the same time. The analysis indicates that flow in the channel just downstream of Great Slave Lake is uniform under both open water and ice covered conditions. However, stage–discharge relationships at the Water Survey of Canada gauging station are affected by variable backwater conditions, particularly when an ice accumulation develops in Providence Rapids. Key words: ice, breakup, backwater curves, hydraulic resistance, river.

Temporal and Spatial Dynamics in Riverbed Chemistry: The Influence of Flow and Sediment Composition

1992 ◽  
Vol 49 (10) ◽  
pp. 2128-2140 ◽  
Author(s):  
P. A. Chambers ◽  
E. E. Prepas ◽  
K. Gibson
Keyword(s):  
Large Scale ◽  
Discharge Rate ◽  
Spatial Dynamics ◽  
Size Composition ◽  
Open Water ◽  
Spatial And Temporal Variability ◽  
Sediment Composition ◽  
Nitrogen And Phosphorus ◽  
Nutrient Pool ◽  
Fine Sediments

To characterize the nutrient pool in the riverbed of an unregulated river in western Canada and identify factors controlling spatial and temporal variability, nitrogen and phosphorus concentrations in open water, porewater, and sediment-exchangeable pools were monitored in the Pembina River, Alberta, at three sites that differed in sediment composition (cobble, sand, and fine sediments). Comparison of porewater chemistry for three years showed that interannual variation was related to discharge rate (22, 87, and 68 m3/s for May–November 1988, 1989, and 1990, respectively) and changes in the size composition of the bottom sediments. However, within-year variations in riverbed chemistry were not correlated with either flow or current velocity. These results suggest that large-scale interannual changes in flow act as a set-point mechanism, defining the particle size composition and chemistry of the riverbed; flow changes of short duration had no predictable effect on riverbed chemistry. Our finding on the highly dynamic nature of riverbed chemistry has important implications for benthic productivity and elemental fluxes between surface waters and the riverbed because dramatic changes in riverbed chemistry can occur in the span of a year even without a flushing scour.

scholarly journals Abundance of Atlantic walrus in Western Nares Strait, Baffin Bay Stock, during summer

2014 ◽  
Vol 9 ◽  
pp. 123 ◽  
Author(s):  
Robert EA Stewart ◽  
Erik W Born ◽  
Rune Dietz ◽  
Mads Peter Heide-Jørgensen ◽  
Frank Farsø Rigét ◽  
...  
Keyword(s):  
Water Surface ◽  
Open Water ◽  
Ellesmere Island ◽  
Baffin Bay ◽  
Nares Strait ◽  
The North ◽  
North Water Polynya ◽  
Odobenus Rosmarus ◽  
North Water ◽  
Odobenus Rosmarus Rosmarus

Atlantic walruses (Odobenus rosmarus rosmarus) belonging to the Baffin Bay subpopulation occur year round in the North Water polynya (NOW) between NW Greenland and eastern Ellesmere Island (Canada). They are hunted for subsistence purposes by residents of the Qaanaaq area (NW Greenland) bordering the NOW to the east and by Canadian Inuit at the entrance to Jones Sound in Nunavut. During the open-water period NW Greenland is virtually devoid of walruses which concentrate along eastern and southern Ellesmere Island at this time of the year. To determine the abundance of walruses in the NOW area, aerial surveys were conducted in August of 1999, 2008, and 2009. In July 2009, nine satellite-linked transmitters were deployed in nearby Kane Basin. Surveys on 9 and 20 August 2009 along eastern Ellesmere Island were the most extensive and were augmented with concomitant data on haul-out and at water surface activity from three (1 F, 2 M) of the nine tags that were still functioning. We therefore focus on the 2009 surveys. Walruses were observed on the ice and in water primarily in Buchanan Bay and Princess Marie Bay where the remaining functional tags were located. The Minimum Counted population (MCP) was 571 on 20 August. Adjusting the MCP of walruses on ice for those not hauled out, the estimate of abundance of walruses in the Baffin Bay stock was 1,251(CV=1.00, 95% CI = 1,226) when adjusted by the proportion of tags ‘dry’ at the time of the survey and 1,249 (CV=1.12, 95% CI = 1,370) when adjusted by the average time tags were dry. The surveys did not cover all potential walrus summering habitat along eastern Ellesmere Island and are negatively biased to an unknown degree.

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