The paper presents the map of intrinsic groundwater vulnerability of the Isonzo/Soča High Plain, which is located between the Collio Hills and the Classical Karst Region and holds an aquifer shared ...between Italy and Slovenia. The map, produced at a scale of 1:25,000 and printed in A0 format, was obtained by means of the SINTACS method and shows the intrinsic vulnerability of the aquifer in terms of seven vulnerability classes, from extremely high to low. It is accompanied by four supplementary sketches that illustrate the geological framework, the bedrock top surface, the groundwater flow paths, the Hazard Index map and three diagrams that summarize the percentages of vulnerability classes and of Hazard Index classes of the study area.
In Slovenia, the unique watershed naturally hosting the marble trout is the Soča River, called Isonzo in Italy. In 1993–1996 molecular data established the existence of extensive hybridization with ...stocked Atlantic domestic lineages which is a threat for this taxon and for the economy of the country established on the angling tourism. Different management actions have been developed for restoring marble genes since 1996: banning stocking of brown trout, revising fishing regulations for anglers and testing genetically brood stock in hatchery for stocking phenotypic and pure marble fry. This long fight against hybridization was genetically surveyed using allozymes, mitochondrial sequences and microsatellites according to the available technique at each period. Despite the irregularity of genotyping along nearly fifteen years after the new management started, it appears that the proportion of domestic lineage in the river dropped regularly of about 2% each year, a positive result for conservative management measures.
The effects of hydropower dams and, in particular, the impacts of reduced river flows on the periphyton community were assessed in the Soča River, Slovenia. Sampling sites were selected upstream and ...downstream of the Podsela and Ajba dams. Sampling was carried out in 1998 during a period of low flows. Reaches downstream from the dams experienced prolonged periods of reduced flows, and a corresponding decrease in flow velocity and water depth. The chain of hydropower dams has stopped sediment inflow from the upstream reach. Below the dams, the oscillations of water temperature, dissolved oxygen and oxygen saturation are much larger than at unregulated sites upstream. The impact of prolonged periods of reduced flows, a lack of sediment supply from upstream and changes in physicochemical variables has caused high periphyton biomass, proliferation of green algae and increases in the number of periphytic algae species below the dams. This has significant implications for the design of environmental flow strategies that provide a sediment supply to maintain a healthy periphyton community. Editor Z.W. Kundzewicz; Associate editor M. Acreman Citation Smolar-Žvanut, N. and Mikoš, M., 2014. The impact of flow regulation by hydropower dams on the periphyton community in the Soča River, Slovenia. Hydrological Sciences Journal , 59 (5), 1032–1045.
According to climate change projections, the Alps will be one of the most affected regions in Europe. A basis for adaptation measures to climate changes is the quantification of the impact. This ...study investigates the impact of projected climate change on the hydrological cycle in the Upper Soča River basin. It is based on the use of climate model data as input for hydrological modelling. The climatic input data used were generated by a global climate model (IPCC A1B emission scenario) and downscaled for local use. Hydrological modelling was performed using the distributed hydrological model MIKE SHE. The simulated impact was quantified by comparing results of the hydrological modelling for the control period (1971–2000) and different scenario periods (2011–2040, 2041–2070, 2071–2100). The climate projections show an increase in the average temperature (+0.9, +2.3, +3.8°C) and negligible changes in average precipitation amounts in the scenario periods. More distinctive are changes in the temporal pattern of mean monthly values (up to +5.2°C and ±45% for precipitation), which result in warmer and wetter winters and hotter and drier summers in the scenario periods. The projected rise in temperature is reflected in the increased actual evapotranspiration, the reduction of snow amount and summer groundwater recharge. Changes of monthly and period average discharges follow the trends of the meteorological variables. Changes in precipitation patterns have a major influence on the projected hydrological cycle and are the most important source of uncertainty. Estimated extreme flows indicated increased hazards related to floods, especially in the near-future scenario period, while in the far future scenario period, distinctive drought conditions are projected.
In the town of Idrija, Slovenia, the world's second largest mercury mine was active for 500 years and about 37,000 tons of mercury has been lost in the environment. Mercury is still drained from ...soil, riverbed and floodplains and transported with the Idrijca and Soča Rivers to the Gulf of Trieste. A part of inorganic mercury is methylated either in the river system, or later in the coastal area, and, due to its bioaccumulation and biomagnification represents potential danger to human health. A 1-D aquatic model MeRiMod was used to simulate hydrodynamics and sediment transport in the river system from Idrija to the Soča River mouth. Transport of particle bound and dissolved mercury as well as potential net methylation of mercury in the river system was simulated. The simulation of an observed flood wave with 20-year recurrence period was performed in order to validate the model. Methylation was simulated at lower discharges, as higher methylation rates occur in such conditions. The measurement data and the MeRiMod model were also used to establish a historical mercury mass balance of the Idrijca and Soča Rivers catchment. Sediment core data from the Gulf of Trieste and the measured concentrations from floodplains were used to verify and calibrate the model. Simulations of different high discharges were performed as most of the transport of particulate mercury occurs within flood wave conditions. Compared to the measurements, the results of the model showed an agreement within an order of magnitude, for the transport of total mercury mostly within a factor of 4, and for the methylation within a factor of 5. However, proper trends of the phenomena were obtained by simulations. The combination of modelling and measurements has resulted in some interesting conclusions about the phenomenon of the transport and transformations of mercury in the observed river system.
The book ('From the Invisible Side of the Sky') talks about the Old Faith religion (Non-Christian faith), Old Faith people as well as about the Old Faith as a way of life which was known to our ...ancestors, before they were Christianized. However, it does not describe something that was alive just a thousand years ago, but it attests life in the 19th and 20th century, here, among us. Pavel Medvešček, half a century ago, managed to win the trust of the Old Faith people in the Soča valley (western Slovenia). He was accepted as their “confessor” and speaker. In doing so, they were led by an awareness that they are the last of their kind and have a unique opportunity to tell the world who they are and how they live in a way that is dying out. In medieval and early modern writings there are descriptions of the Old Faith in Europe, but their authors were Christians, mostly even Christian priests. They were necessarily deficient informed, their story biased, pejorative, mocking, their image of the Old Faith inevitably completely distorted. Through Medvešček as a writer, in the book the Old Faith people themselves talk about themselves. This did not succeed ever before and elsewhere, because they constantly have to hide and to pretend. It is this 'inner voice' which gives the book an incomparable, unique value of utmost importance, especially in an increasingly wilder, globalized world.
We present a paleoenvironmental reconstruction for the mountain fringe between the South-Eastern Alps and the Northern Dinarides (NE-Italy/W-Slovenia) during the Last Glacial Maximum. We focused on a ...new sedimentary and paleoecological archive spanning the LGM acme, located in an aggrading, permanently flooded and ponded plain, dammed by an active fluvioglacial megafan. The ecosystem reconstruction, based on two high resolution pollen records, is supported by a rich plant macrofossil flora and constrained by a robust radiocarbon chronology between 26 and 22calka BP. We show evidence for persistence of boreal trees and of different open boreal forest types throughout the LGM at the south-eastern mountain fringe of the Alps and the Northern Dinarides. Fire frequency is responsible for high, oscillating forest openness. The paleobotanical record is discussed in the light of the ecogeographic diversity of the region. A belt formed by Swiss stone pine, larch and dwarf mountain pine on limestone bedrock, and accompanied by Spruce in the floodplain, extended uphill, while proximal outwash plain supported Scots pine and dwarf mountain pine. These differences arise from groundwater regimes rather than from local climate variability. A steep moisture gradient from the semiarid pedoclimatic regime prevailing in the Adriatic alluvial plain to the forested mountain fringe is related to the orographic rainout triggered by southern air circulation. Mesophytic broad-leaved forest trees did not withstand the LGM temperature extremes in zonal ecosystems at the Alpine–Dinaric fringe; however, the fossil evidence suggests a number of microrefugia in karstic and thermal spring habitats of the northern Adriatic.
•Paleoenvironmental reconstruction at Alps–Dinarides fringe during the Last Glacial Maximum•Relationships between regional geological frame, sedimentary environments, and forest history•Persistence of trees and of different types of open boreal forest throughout the LGM
Soil degradation is a major environmental problem in many parts of the world, including Slovenia. The spatially distributed WATEM/SEDEM model can be used to identify the most critical parts of the ...catchment with regard to soil erosion. Five Slovenian (Central Europe) catchments with inhomogeneous topography, land use, geological conditions, hydro-meteorological properties and sizes (catchment areas between 1 and 2000 km²) were modeled with calibrated parameters, while the WATEM/SEDEM model was calibrated with an automatic parameter estimation procedure, which is model independent. Both direct and indirect information regarding sediment yields, including turbidity measurements, daily suspended sediment concentration observations and bed load observations, were used for the WATEM/SEDEM model’s calibration. A detailed rainfall erosivity (R) factor map, which was constructed from 5-min rainfall data from 31 pluviographic meteorological stations, was used as one of the inputs for the WATEM/SEDEM model. The calculated mean annual soil loss was between 0.3 and 7.4 t/ha/year, and the sediment delivery ratio (SDR) ranged from 0.07 to 0.22 for 5 modeled catchments. The results indicate that the SDR decreases with increasing catchment area; however, the ratio between the average sediment yield and mean soil erosion obviously depends on many other factors, e.g., topography, climatic and geological conditions. The parcel trap efficiency parameter for forests had the greatest influence on the WATEM/SEDEM model’s outputs in all five case studies.
Shallow lateral shear layers forming between flows with different velocities, though essential for mixing processes in natural streams, have been examined only in laboratory settings using smooth, ...fixed‐bed channels. This paper reports the results of an experimental study of a shear layer in a straight reach of a natural river where the layer, in contrast to the two‐dimensional structure observed in the laboratory, is highly three‐dimensional. The study included pronounced transverse pressure gradients, which influenced shear layer structure compared to flume experiments. It also introduces an analysis that complements conventional theory on mixing layers. The lateral velocity gradient between the flows downstream from a splitter plate placed in the river, the principal controlling factor, was adjusted for three experimental runs to determine the influence of different gradients on shear‐layer dynamics. In each run, detailed three‐dimensional measurements of mean and turbulent characteristics were obtained at five cross sections downstream from the splitter plate. Although experimental results agreed with conventional mixing‐layer theories with respect to turbulence, the dynamics of the shear layers were dominated by the mean lateral fluxes of momentum. After re‐examining the governing equations, we developed a parabolic equation describing the shear layer evolution and several scaling relations for essential terms of the energy budget: mean and turbulent lateral fluxes of momentum, turbulent kinetic energy, and dissipation rates. The study also provides insight into the spectral dynamics of turbulence in the shear layer and clarifies previous observations reported for confluences in natural streams.
PDF
