Hydrological System of the Plitvice Lakes—Trends and Changes in Water Levels, Inflows, and Losses

The Plitvice Lakes National Park is inscribed on UNESCO’s World Heritage List. The lake system is composed of 16 cascading lakes of different sizes separated by tufa barriers, which are the park’s key phenomenon. The lakes are characterized by highly diverse trends of the characteristic hydrological indicators—mean annual water levels, discharges, and tufa barrier growth. The analyses carried out in this paper identified that in the period before the early 1990s, Kozjak Lake had a trend of decreasing discharges, together with a trend of increasing water levels and growing tufa barriers. In contrast to this, in the period after 2001, a trend of increasing discharges was recorded, as well as a trend of decreasing water levels and decreasing tufa barriers. A potential cause of the barriers decreasing in size were the extremely high discharges during the last decade, which resulted in increased erosion of the tufa barriers. Losses of water due to the sinking from the lake system as well as the upper Korana course were confirmed, and it was identified that during the analyzed period the losses had not changed significantly. It was determined that the losses of water from Kozjak Lake occurred during low-water periods; however, they depended not only on the quantity of water flowing through the lakes but also on the hydrological conditions underground. The analyses carried out and the methodological procedures used in the analyzed area of the Plitvice Lakes are useful examples for the performance of analyses at similar lakes in karst formed by tufa deposition processes.

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Black alder forests (type 91E0* Natura 2000 type E.2.1.9. NHC) in the Plitvice Lakes National Park

Šumarski list ◽

10.31298/sl.143.7-8.1 ◽

2019 ◽

Vol 143 (7-8) ◽

pp. 304-305

Author(s):

Joso Vukelić ◽

Marko Orešković ◽

Ivana Plišo Vusić ◽

Igor Poljak ◽

Giacomo Mei ◽

...

Keyword(s):

National Park ◽

Habitat Type ◽

Natura 2000 ◽

Alnus Glutinosa ◽

Water Levels ◽

Acer Pseudoplatanus ◽

Higher Plant ◽

Black Alder ◽

Primula Vulgaris ◽

Plitvice Lakes

The paper presents the first results of monitoring Natura 2000 habitat type 91E0*in the Plitvice Lakes National Park (Croatia). This type is represented in black alder forests (Alnus glutinosa /L./ Gaertn.) on an area of 44 ha. There, following the Braun-Blanquet method (1964), 25 plots were set up and relevés made, with 175 species of higher plant species recorded. Their environmental and sociological features suggest wetland and periodically flooded habitats with high ground water levels throughout the year, hence hygrophytes are decisive for the community structure. In addition, there is a moderate share of mesophilic species that are not present in the wetland black alder forests along the Sava and Drava rivers in the lowland part of northern Croatia. A comparison of black alder forests of the Plitvice Lakes NP with other black alder syntaxa in Croatia (Figure 2, Table 3) demonstrates that, together with other alder stands in the Dinaric region of Croatia, they belong to the group of wetland forests of the alliance Alnion glutinosae. Their differentiating species with regard to other syntaxa of the alliances Alnion glutinosae and Alnion incanae in Croatia are Fraxinus excelsior, Daphne mezereum, Viburnum lantana, Cirsium oleraceum, Crepis paludosa, Equisetum arvense, Paris quadrifolia, Thalictrum aquilegifolium, Valeriana dioica, Veratrum album, Acer pseudoplatanus, Chaerophyllum hirsutum, Lonicera xylosteum, Filipendula ulmaria, Knautia drymeia, Cruciata glabra. In addition, the researched stands in the Plitvice Lakes NP demonstrate individuality with regard to other stands of the Croatian Dinarides through the differentiating species of Phalaris arundinacea, Dactylorhiza maculata, Cirsium arvense, Primula vulgaris, Listera ovata, Carex acutiformis, C. paniculata, Succisa pratensis, Gentiana asclepiadea. Black alder forests in the Plitvice Lakes NP were created by successive processes in non-forest areas after their fall out of use (Figure 1). They grow by watercourses in karst depressions with occasionally stagnant surface water. Here the river courses are slowed down and distanced from the slopes and surrounding massifs, hence zonal forests do not have a dominant influence on the floral composition. The researched forests are classified in the class Alnetea glutinosae Br.-Bl. et Tx. 1943, order Alnetalia glutinosae Tx. 1937, and alliance Alnion glutinosae Malcuit 1929. They exhibit greatest similarity to the Central European association Carici acutiformis-Alnetum glutinosae. However, these results should not be generalized for the entire Dinaric region of Croatia. Detailed studies of black alder forests in the Dinarides are pending and their results will determine their nomenclature and syntaxonomic character.

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Autonomous Vehicles Mapping Plitvice Lakes National Park, Croatia

Remote Sensing ◽

10.3390/rs12223683 ◽

2020 ◽

Vol 12 (22) ◽

pp. 3683

Author(s):

Nadir Kapetanović ◽

Branko Kordić ◽

Antonio Vasilijević ◽

Đula Nađ ◽

Nikola Mišković

Keyword(s):

High Resolution ◽

Autonomous Vehicles ◽

National Park ◽

Unmanned Aircraft ◽

Multibeam Sonar ◽

Autonomous Surface Vehicle ◽

Average Maximum ◽

Hydrological System ◽

Data Points ◽

Plitvice Lakes

Plitvice Lakes National Park is the largest national park in Croatia and also the oldest from 1949. It was added to the UNESCO World Natural Heritage List in 1979, due to the unique physicochemical and biological conditions that have led to the creation of 16 named and several smaller unnamed lakes, which are cascading one into the next. Previous scientific research proved that the increased amount of dissolved organic matter (pollution) stops the travertine processes on Plitvice Lakes. Therefore, this complex, dynamic but also fragile geological, biological and hydrological system required a comprehensive limnological survey. Thirteen of the sixteen lakes mentioned above were initially surveyed from the air by an unmanned aircraft equipped with a survey grade GNSS and a full frame high-resolution full-screen camera. From these recordings, a georeferenced, high-resolution orthophoto was generated, on which the following surveys by a multibeam sonar depended. It is important to mention that this was the first time that these lakes had ever been surveyed both with the multibeam sonar technique and with such a high-resolution camera. Due to the fact that these thirteen lakes are difficult to reach and often too shallow for a boat-mounted sonar, a special autonomous surface vehicle was developed. The lakes were surveyed by the autonomous surface vehicle mounted with a multibeam sonar to create detailed bathymetric models of the lakes. The missions were planned for the surface vehicle based on the orthophoto from the preliminary studies. A detailed description of the methodology used to survey the different lakes is given here. In addition, the resulting high-resolution bathymetric maps are presented and analysed together with an overview of average, maximum depths and number of data points. Numerous interesting depressions, which are phenomena consistent with previous studies of Plitvice Lakes, are noted at the lake beds and their causes are discussed. This study shows the huge potential of remote sensing technologies integrated into autonomous vehicles in terms of much faster surveys, several orders of magnitude more data points (compared to manual surveys of a few decades ago), as well as data accuracy, precision and georeferencing.

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Characteristics of Pocket Gopher Populations in Relation to Selected Environmental Factors in Pelican Valley, Yellowstone National Park

The UW National Parks Service Research Station Annual Reports ◽

10.13001/uwnpsrc.1979.2179 ◽

1979 ◽

Vol 3 ◽

pp. 133-137

Author(s):

C. Youmans ◽

R. Moore

Keyword(s):

Environmental Factors ◽

Yellowstone National Park ◽

National Park ◽

Ursus Arctos ◽

Water Levels ◽

Specific Information ◽

Pocket Gopher ◽

Pocket Gophers ◽

Thomomys Talpoides ◽

Ursus Arctos Horribilis

Several important environmental factors which affect the dynamics of pocket gopher populations have been identified: water content at peak snowpack and depth of snow in spring (Hansen and Ward, 1966; Reid, 1973); weather and Its influence on annual food supplies and cover (Howard and Childs, 1959); production of annual and perennial forbs (Keith et al., 1959; Tietjen et al., 1967); and ground water levels and snow depths (Ingles, 1949; Hansen, 1962). A need for specific information on pocket gophers in Pelican Valley, Yellowstone National Park arose from interest in interactions between grizzly bears (Ursus arctos horribilis) and northern pocket gophers (Thomomys talpoides). Mealey (1975) and Graham (1978) suggested that pocket gophers and their caches may serve as seasonally important food items for grizzlies in Yellowstone National Park.

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The interrelation between development, management, and management issues in Plitvice Lakes National Park

Challenges of tourism development in protected areas of Croatia and Slovenia ◽

10.26493/978-961-7055-08-5.211-239 ◽

2020 ◽

pp. 211-239

Author(s):

Izidora Marković Vukadin

Keyword(s):

National Park ◽

Development Management ◽

Plitvice Lakes ◽

Management Issues

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Partitioning CO<sub>2</sub> net ecosystem exchange fluxes on the microsite scale in the Lena River Delta, Siberia

10.5194/bg-2018-311 ◽

2018 ◽

Cited By ~ 2

Author(s):

Tim Eckhardt ◽

Christian Knoblauch ◽

Lars Kutzbach ◽

Gillian Simpson ◽

Evgeny Abakumov ◽

...

Keyword(s):

Water Table ◽

Net Ecosystem Exchange ◽

Growing Season ◽

Arctic Tundra ◽

High Water ◽

Water Levels ◽

River Delta ◽

Lena River ◽

Hydrological Conditions ◽

Lena River Delta

Abstract. Arctic tundra ecosystems are currently facing rates of amplified climate change. This is critical as these ecosystems store significant amounts of carbon in their soils, which can be mineralized to CO2 and CH4 and released to the atmosphere. To understand how the CO2 net ecosystem exchange (NEE) fluxes will react to changing climatic conditions, it is necessary to understand the individual responses of the physiological processes contributing to CO2 NEE. Therefore, this study aimed: (i) to partition NEE fluxes at the soil-plant-atmosphere interface in an arctic tundra ecosystem; and (ii) to identify the main environmental drivers of these fluxes. Hereby, the NEE fluxes were partitioned into gross primary productivity (GPP) and ecosystem respiration (Reco) and further into autotrophic (RA) and heterotrophic respiration (RH). The study examined flux data collected during the growing season in 2015 using closed chamber measurements in a polygonal tundra landscape in the Lena River Delta, northeastern Siberia. The measured fluxes on the microscale (1 m–10 m) were used to model the NEE, GPP, Reco, RH, RA and net ecosystem production (NPP) over the growing season. Here, for the first time, the differing response of in situ measured RA and RH fluxes from permafrost-affected soils to hydrological conditions have been examined. It was shown that low RA fluxes are associated to a high water table, most likely due to the submersion of mosses, while an effect of water table fluctuations on RH fluxes was not observed. Furthermore, this work found the polygonal tundra in the Lena River Delta to be a sink for atmospheric CO2 during the growing season. Spatial heterogeneity was apparent with the net CO2 uptake at a wet, depressed polygon center being more than twice as high as that measured at a drier polygon rim. In addition to higher GPP fluxes, the differences in NEE between the two microsites were caused by lower Reco fluxes at the center compared to the rim. Here, the contrasting hydrological conditions caused the CO2 flux differences between the microsites, where high water levels lad to lower decomposition rates due to anoxic conditions.

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An assessment of the factors determining rotifer assemblage in river-lake systems: the effects of seasonality and habitat

Zoologia (Curitiba) ◽

10.3897/zoologia.36.e24191 ◽

2019 ◽

Vol 36 ◽

pp. 1-5

Author(s):

Moacyr Serafim-Júnior ◽

Gilmar Perbiche-Neves ◽

Fabio Lansac-Toha

Keyword(s):

Species Richness ◽

Aquatic Macrophytes ◽

Hydrological Cycle ◽

High Water ◽

Water Levels ◽

Natural Environments ◽

Ecological Attributes ◽

Lake System ◽

The Mean ◽

Lake Systems

Zooplankton exhibit several trends of variation in space and time, and these trends can be more evident in natural environments without anthropic perturbations. Examples of anthropic factors are climate change, eutrophication and construction of reservoirs. This study evaluated the influence of three factors – seasonality, type of environment and the presence of aquatic macrophytes – on various ecological attributes of rotifers in a river-lake system located in the Paraná River floodplain. Monthly samplings were conducted during 1993 and 1994. The mean species richness per sample was 60 species. The seasonality and the type of environment influenced the ecological attributes of rotifer assemblages, while the presence or absence of aquatic macrophytes did not. Species richness was highest in the lake system and during the months when water levels were low. Multivariate analysis indicates a small group of species associated with the low water-level phase. In contrast, many species were associated with high water levels or increasing water levels. The seasonal variation of hydrological cycle and the type of environment are the most important factors for rotifer structure in natural conditions.

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Flow-Based Structural Modelling and Dynamic Simulation of Lake Water Levels

Green Technologies ◽

10.4018/978-1-60960-472-1.ch413 ◽

2011 ◽

pp. 798-814

Author(s):

Nashon Juma Adero ◽

John Bosco Kyalo Kiema

Keyword(s):

Water Balance ◽

Water Level ◽

Dynamic Simulation ◽

Lake Water ◽

Complex Dynamics ◽

Water Levels ◽

Major Question ◽

Modern Computer ◽

Hydrological System ◽

Dynamic Simulation Model

The continuing decline in lake water levels is both a concern and daunting challenge to scientists and policymakers in this era, demanding a rethinking of technological and policy interventions in the context of broader political and socio-economic realities. It is self-evident that diverse factors interact in space and time in complex dynamics to cause these water-level changes. However, the major question demanding sound answers is how these factors interact and by what magnitude they affect lake water balance with time. This chapter uses Lake Victoria’s hydrological system to shed light on the extensive and flexible modelling and simulation capabilities availed by modern computer models to understand the bigger picture of water balance dynamics. The study used the 1950-2000 hydrological data and riparian population growth to develop a dynamic simulation model for the lake’s water level. The intuitive structure of the model provided clear insights into the combined influence of the main drivers of the lake’s water balance. The falling lake water levels appeared to be mainly due to dam outflows at the outlet and reduced rainfall over the lake. The ensuing conclusions stressed the need for checks against over-release of lake water for hydropower production and measures for sustainable land and water management in the entire basin.

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Eco-epidemiological and pathological features of wildlife mortality events related to cyanobacterial bio-intoxication in the Kruger National Park, South Africa

Journal of the South African Veterinary Association ◽

10.4102/jsava.v87i1.1391 ◽

2016 ◽

Vol 87 (1) ◽

Cited By ~ 7

Author(s):

Roy Bengis ◽

Danny Govender ◽

Emily Lane ◽

Jan Myburgh ◽

Paul Oberholster ◽

...

Keyword(s):

South Africa ◽

National Park ◽

Field Investigation ◽

Water Levels ◽

Kruger National Park ◽

Cyanobacterial Blooms ◽

Toxicity Tests ◽

Management Options ◽

South Central ◽

Wildlife Mortality

Over the past decade, several clustered, multispecies, wildlife mortality events occurred in the vicinity of two man-made earthen dams in the southern and south central regions of the Kruger National Park, South Africa. On field investigation, heavy cyanobacterial blooms were visible in these impoundments and analysis of water samples showed the dominance of Microcystis spp. (probably Microcystis aeruginosa). Macroscopic lesions seen at necropsy and histopathological lesions were compatible with a diagnosis of cyanobacterial intoxication. Laboratory toxicity tests and assays also confirmed the presence of significant levels of microcystins in water from the two dams. These outbreaks occurred during the dry autumn and early winter seasons when water levels in these dams were dropping, and a common feature was that all the affected dams were supporting a large number of hippopotamuses (Hippopotamus amphibius). It is hypothesised that hippopotamus’ urine and faeces, together with agitation of the sediments, significantly contributed to internal loading of phosphates and nitrogen – leading to eutrophication of the water in these impoundments and subsequent cyanobacterial blooms. A major cause for concern was that a number of white rhinoceros (Ceratotherium simum) were amongst the victims of these bio-intoxication events. This publication discusses the eco-epidemiology and pathology of these clustered mortalities, as well as the management options considered and eventually used to address the problem.

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