scholarly journals Long-term analysis of fish assemblage structure in the middle section of the Sava River – The impact of pollution, flood protection and dam construction

2019 ◽  
Vol 651 ◽  
pp. 143-153 ◽  
Author(s):  
Marina Piria ◽  
Predrag Simonović ◽  
Davor Zanella ◽  
Marko Ćaleta ◽  
Nikica Šprem ◽  
...  
Keyword(s):  
Fish Assemblage ◽  
Flood Protection ◽  
Dam Construction ◽  
Fish Assemblage Structure ◽  
Middle Section ◽  
Sava River ◽  
The Impact ◽  
Term Analysis ◽  
The Sava River

scholarly journals Synthesis of past isotope hydrology investigations in the area of Ljubljana, Slovenia

Geologija ◽  
2020 ◽  
Vol 63 (2) ◽  
pp. 251-270
Author(s):  
Klara Nagode ◽  
Tjaša Kanduč ◽  
Sonja Lojen ◽  
Branka Bračič Železnik ◽  
Brigita Jamnik ◽  
...  
Keyword(s):  
Surface Water ◽  
Stable Isotope ◽  
Large Scale ◽  
Numerical Data ◽  
Domestic Water ◽  
Sava River ◽  
The Impact ◽  
Ljubljansko Barje ◽  
The Sava River

Water isotope investigations are a powerful tool in water resources research as well as in understanding the impact that humans have on the water cycle. This paper reviews past hydrological investigations of the Ljubljansko polje and Ljubljansko barje aquifers that supply drinking water to the City of Ljubljana, with an emphasis on hydrogen, oxygen and carbon stable isotope ratios. Information about the methods used and results obtained are summarised, and the knowledge gaps identified. Overall, we identified 102 records published between 1976 and 2019. Among them, 41 reported stable isotope data of groundwater, surface water and precipitation and were further analysed. Isotope investigations of the Ljubljansko barje began in 1976, while groundwater and surface water investigations of the Ljubljansko polje and along the Sava River began as late as 1997. Isotope investigations of carbon started even later in 2003 in the Ljubljansko polje and in 2010 in the Ljubljansko barje. These investigations were performed predominantly in the frame of short-term groundwater research projects at five main wellfields and sites along the Sava River. Almost no large-scale, long-term stable isotope studies have been conducted. The exceptions include groundwater monitoring by the Union Brewery in Ljubljana (2003- 2014) and precipitation in Ljubljana since 1981. Since 2011, more detailed surveys of the Ljubljansko barje were performed, and in 2018, the first extensive investigation started at wellfields and objects that form part of the domestic water supply system. Given the number of available studies, we felt that publishing all the numerical data and appropriate metadata would allow for a better understanding of the short and long-term dynamics of water circulation in the urban environment. In the future, systematic long-term approaches, including the appropriate use of isotopic techniques, are needed.

scholarly journals Long-term study of reservoir cascade in south-eastern Brazil reveals spatio-temporal gradient in fish assemblages

2018 ◽  
Vol 69 (12) ◽  
pp. 1983 ◽  
Author(s):  
Raquel Coelho Loures ◽  
Paulo Santos Pompeu
Keyword(s):  
River Basin ◽  
Fish Species ◽  
Fish Assemblage ◽  
Native Species ◽  
Fish Assemblages ◽  
Native Fish ◽  
Fish Diversity ◽  
Fish Assemblage Structure ◽  
Long Term Study

In reservoir cascades, effects on fish assemblages are expected to strengthen over time and transfer from one reservoir to an adjacent one. To test this, fish-assemblage data from 23 years of monitoring in the Araguari reservoir cascade system, upper Paraná River basin, were analysed. The results showed a clear reduction in richness of native and migratory fish species and an increase of non-native species, following reservoir formation. Migratory species richness was higher in reservoirs that presented habitats similar to lotic stretches or tributaries upstream of the impounded area. There was a clear tendency for native species to decline and non-native fish species to increase, in a downstream direction. Fish assemblages became increasingly dissimilar as reservoirs became more distant from each other (longitudinal gradient) and were dominated by small and medium-sized species. Alongside longitudinal position, reservoir area, age and the presence of herbivorous non-native fish were found to be important predictors of variation in fish-assemblage structure. Results from the present study help clarify the potential accumulated impacts of reservoir cascades on fish diversity, which must be carefully considered in river-basin inventories for hydropower plants, and reinforce the importance of long-term monitoring, considering longitudinal and lateral dimensions of the basin.

Time Rules and Time Budgets in Legislatures

2020 ◽  
Author(s):  
Michael Koß
Keyword(s):  
Social Life ◽  
Public Policies ◽  
Time Budgets ◽  
Agenda Control ◽  
Ideal Types ◽  
The Impact ◽  
Term Analysis

This chapter examines the impact of the alleged acceleration of social life on legislatures. Theoretically, acceleration can be regarded as a constraint or an opportunity. Conceptually, a number of time rules granting various subgroups of legislators different time budgets are used to cope with acceleration. The most important of these rules are those regarding agenda control and committee power. Different time rules and time budgets culminate in two procedural ideal types, talking and working legislatures. Empirically, both ideal types are clearly identifiable and have distinct consequences for public policies. A tentative long-term analysis shows no evidence for an ever-increasing acceleration of lawmaking in five lower chambers.

scholarly journals Assessing the impact of climate on annual and seasonal discharges at the Sremska Mitrovica station on the Sava River, Serbia

2021 ◽  
Author(s):  
Igor Leščešen ◽  
Mojca Šraj ◽  
Milana Pantelić ◽  
Dragan Dolinaj
Keyword(s):  
Distribution Functions ◽  
Negative Trend ◽  
Flood Frequency Analysis ◽  
Positive Trend ◽  
Discharge Data ◽  
Sava River ◽  
Increasing Trend ◽  
The Impact ◽  
Gauging Station ◽  
The Sava River

Abstract Flood frequency analysis was performed on annual maxima series for 90 years (1928–2017) of discharge data recorded at the Sremska Mitrovica gauging station on the Sava River. The three-parameter distributions (PearsonIII, Log-PearsonIII) are more suitable for modelling annual maxima than distribution functions with only two parameters (Normal, Log-normal, Gumbel). The Mann–Kendall test statistic indicated that there is no statistically significant trend identified in annual maximum discharges or average annual discharges. A positive increasing trend was observed in annual temperature, while annual precipitation shows a decreasing trend which is non-significant. The seasonality analysis found a statistically non-significant weak negative trend in discharge in spring, summer and autumn and a statistically non-significant weak positive trend in winter. During winter, spring, and summer a non-significant negative trend in precipitation was observed, while autumn has experienced a statistically significant increasing trend. Temperatures show a positive trend in all seasons, but only temperatures during the warm period show a statistically significant increase. The results demonstrate that decreasing discharges of the Sava River at the Sremska Mitrovica gauging station are mainly the consequence of decreasing precipitation and increasing temperature (increasing evaporation), which is consistent with the results of other studies of the region.

scholarly journals Long-term effects of a rural landscape on the structure and trophic organization of a fish assemblage

2019 ◽  
Vol 31 ◽  
Author(s):  
Pedro Sartori Manoel ◽  
Virginia Sanches Uieda
Keyword(s):  
Fish Assemblage ◽  
Assemblage Structure ◽  
Rural Landscape ◽  
Environmental Data ◽  
Diet Analysis ◽  
Fish Diet ◽  
Fish Assemblage Structure ◽  
Long Term Effects ◽  
Over Time

Abstract Aim We investigated the long-term effects of a rural landscape on the structure and trophic organization of a fish assemblage. Methods We compared environmental data and data from fish assemblage structure and trophic organization sampled in a stream located in a rural area, within a time gap of 20 years. Results We observed only punctual changes in the environmental variables and fish structure, which may not be related to the rural landscape. In fish diet, insectivory remained predominant in all sample periods. However, when we analyzed the groups of hexapods consumed by the fish species, we found a substitution of Ephemeroptera and Trichoptera by Diptera over time. Conclusions Although the fish assemblage structure was not affected, the insectivore diet analysis showed that the stream stretch could be in an ongoing process of environmental quality loss, once the simplification in the macroinvertebrates assemblage structure over time is indicative of environmental degradation.

Long-term analysis of the impact of longitudinal barriers on motorway safety

2013 ◽  
Vol 59 ◽  
pp. 443-451 ◽  
Author(s):  
Jean-Louis Martin ◽  
Colette Mintsa-Eya ◽  
Clément Goubel
Keyword(s):  
The Impact ◽  
Term Analysis
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