Kraški izviri predstavljajo pomemben vir pitne vode tako v Sloveniji kot v svetu. Zaradi specifične zgradbe so kraški vodonosniki v večini zelo občutljivi na onesnaženje. Avtor na primeru kraškega ...izvira Bistrica izpostavi problematiko varovanja kraške podtalnice ter predstavi glavne pomanjkljivosti ter slabosti sedanje zakonodaje in uveljavljene prakse na področju varovanja kraških vodonosnikov v Sloveniji. Kljub relativno ugodnim razmeram za varovanje (redka poseljenost, manj intenzivno kmetijstvo,…) v primerjavi s kraškimi območji drugod po svetu je veliko pomembnih kraških izvirov slabo zavarovanih. Vodovarstveni režimi so največkrat slabo definirani, nadzor nad izvajanjem zaščitnih ukrepov pa neučinkovit. Karst springs are important drinking water sources both in Slovenia and elsewhere in the world. Due to their specific structure, karst aquifers are in most cases highly vulnerable to pollution. Through the example of the Bistrica karst spring, the author highlights the problems of karst groundwater protection and presents the main shortcomings and weaknesses of the relevant legislation in force and of established practices in the field of the protection of karst aquifers in Slovenia. Despite relatively favourable conditions for water protection (scarce population, less intensive agricultural activities etc.) as compared with karst areas elsewhere in the world, many important karst springs in Slovenia are improperly protected. Water protection regimes are often established inappropriately and control over the implementation of protective measures is inefficient.
Time series analyses are often used for the investigation of karst aquifers, but are only rarely employed in a way of using a large number of spatially distributed time series. Furthermore, only a ...small number of applications employ other types of hydrological data apart from rainfall, water level and discharge. The presented study of the Malenščica karst spring aquifer underlines the usefulness of the simultaneous auto- and cross-correlation analysis of daily and hourly hydrological data sets, including discharge, water level, temperature, electrical conductivity and rainfall on a regional scale. The results of the autocorrelation analysis show that the storage capacity of the spring is moderate, but this does not indicate that the system, whichis characterized by prevailing conduit porosity, is less intensively karstified. This suggests that well-karstified systems of a more complex structure can have higher memory effects than less complex systems. The results of the cross-correlation analysis show that karst springs and watercourses in the investigated area react instantly and simultaneously to rather homogeneous precipitation, yet withdifferent intensity. In suchcases a cross-correlation analysis between rainfall or ponors as inputs and springs as outputs does not provide sufficient information on the hydrogeological functioning of the system, whereas the results of a cross-correlation analysis of electrical conductivity data sets provide valuable information on its functioning and can be easily compared to those obtained by tracer tests. On the other hand, the applicability of a temperature time series in suchcomplex karst systems is limited. A comparative analysis of the results of the time series analyses performed in successive hydrological years has proven that the selection of the hydrological year can have strong effects on the results of a time series analysis.
Some previous studies have shown that chaotic dynamics in the balanced state, i.e., one with balanced excitatory and inhibitory inputs into cortical neurons, is the underlying mechanism for the ...irregularity of neural activity. In this work, we focus on networks of current-based integrate-and-fire neurons with delta-pulse coupling. While we show that the balanced state robustly persists in this system within a broad range of parameters, we mathematically prove that the largest Lyapunov exponent of this type of neuronal networks is negative. Therefore, the irregular firing activity can exist in the system without the chaotic dynamics. That is the irregularity of balanced neuronal networks need not arise from chaos.
This article deals with the results of seven years of measurements of sediment release from the flysch badlands in the Rokava River headwaters. Measurements of sediment production were carried out in ...erosion plots, and measurements of cliff (or rockwall) retreat using erosion pins. Selected meteorological time series from the Portorož Airport meteorological station were included in the analysis. The calculation showed that from 2008 to 2015 (149 measurements) sediment production was 36 kg/m² per year and the flysch cliff retreated by 146 mm or 21 mm per year. The amount of sediment produced is moderately positively correlated with the number of days between successive measurements (r = 0.51), with a recorded daily transition of air temperature over/below 0 °C (r = 0.56) and slightly more weakly correlated with the precipitation amount (r = 0.45). On the other hand, the amount of sediment produced has a low negative correlation with average air temperature (r = −0.29) and average minimum air temperature (r = −0.30). However, no statistically significant correlation was calculated between the amount of sediment produced and average wind speed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Za določitev vodovarstvenih območij ter za načrtovanje rabe prostora v zaledju zajetih kraških izvirov in vrtin se praviloma uporablja koncept kartiranja ranljivosti kraških vodonosnikov. Obstaja več ...med seboj različnih metodologij kartiranja ranljivosti kraških vodonosnikov in pregled znanstvene literature kaže na določene razlike v definiciji pojma ranljivosti. Avtorja predlagata razlikovanje med pojmoma ranljivost in občutljivost kraških vodonosnikov, saj prvi vsebuje več informacij, ki jih potrebujemo za primerno varovanje. Pri razlagi pojmov se avtorja opirata na konceptualna The concept of karst aquifer vulnerability mapping is commonly used for the determination of water protection zones and planning of land use in the background of the captured karst sources and wells. Several different methodologies for karst aquifer vulnerability mapping exist and the examination of scientific literature shows considerable variations in the definition of the term vulnerability. The authors suggest the distinction between the terms vulnerability and sensitivity of karst aquifers, since the former includes more information, which are required for efficient protection. The interpretation of the applied terms is founded on the conceptual background of the environmental vulnerability studies, which are declared with the Slovene 1993 Environmental Protection Act.
Prispevek obravnava kartiranje onesnaževalcev podtalnice na alpski kraški planoti Velika planina. Kljub temu, da na planoti ni stalne poselitve, je kakovost vode v izvirih pod planoto ogrožena zaradi ...športne, turistične in živinorejske aktivnosti na planoti. V izvirih so že zabeležili onesnaženje, kar kaže na pomanjkljivosti upravljanja s pitno vodo tudi na neposeljenih območjih alpskega krasa, ki so sicer z vidika varovanja zelo primerna za zaščito. The present paper presents the hazard mapping of groundwater on the Velika planina alpine karst plateau. There are no permanent residents on the plateau. Nevertheless, some serious hazards to the quality of the respective karst springs are arising from sports, tourist and farming activities. Some pollution has been already recorded in springs, showing the shortcomings of drinking water management also in uninhabited alpine karst areas, which are ordinarily very favourable for water protection.
Prispevek obravnava značilnosti 17 kraških presihajočih jezer Zgornje Pivke. V času dolgotrajnega deževja v novembru 2000, ko je izmerjena količina dežja več kot trikrat presegala povprečno mesečno ...količino padavin, se je voda, po več desetletjih, pojavila v vseh jezerih. Izjemoma so bile poplavljene tudi številne druge manjše kraške globeli, kjer ojezeritve še niso bile dokumentirane. S pomočjo terenskih meritev in interpretacijo letalskih posnetkov so bili izmerjeni vodostaji in površine jezer ter prostornina vode v njih. The article presents the characteristics of the 17 intermittent karst lakes of Upper Pivka. During the extended precipitation in November 2000, when the amount of precipitation was more than three times the average, all the lakes were flooded for the first time in several decades. Also several additional small karst depressions were flooded, where overflowing had never been recorded before. By combining field observations with the interpretation of aerial photographs the water level, the extent of the lakes and the volumes of containing water were calculated.
The existence of electrical communication among pyramidal cells (PCs) in the adult cortex has been debated by neuroscientists for several decades. Gap junctions (GJs) among cortical interneurons have ...been well documented experimentally and their functional roles have been proposed by both computational neuroscientists and experimentalists alike. Experimental evidence for similar junctions among pyramidal cells in the cortex, however, has remained elusive due to the apparent rarity of these couplings among neurons. In this work, we develop a neuronal network model that includes observed probabilities and strengths of electrotonic coupling between PCs and gap-junction coupling among interneurons, in addition to realistic synaptic connectivity among both populations. We use this network model to investigate the effect of electrotonic coupling between PCs on network behavior with the goal of theoretically addressing this controversy of existence and purpose of electrotonically coupled PCs in the cortex.
The initial value problem for the focusing Manakov system with nonzero boundary conditions at infinity is solved by developing an appropriate inverse scattering transform. The analyticity properties ...of the Jost eigenfunctions are investigated, and precise conditions on the potential that guarantee such analyticity are provided. The analyticity properties of the scattering coefficients are also established rigorously, and auxiliary eigenfunctions needed to complete the bases of analytic eigenfunctions are derived. The behavior of the eigenfunctions and scattering coefficients at the branch points is discussed, as are the symmetries of the analytic eigenfunctions and scattering coeffiecients. These symmetries are used to obtain a rigorous characterization of the discrete spectrum and to rigorously derive the symmetries of the associated norming constants. The asymptotic behavior of the Jost eigenfunctions is derived systematically. A general formulation of the inverse scattering problem as a Riemann-Hilbert problem is presented. Explicit relations among all reflection coefficients are given, and all entries of the scattering matrix are determined in the case of reflectionless solutions. New soliton solutions are explicitly constructed and discussed. These solutions, which have no analogue in the scalar case, are comprised of dark-bright soliton pairs as in the defocusing case. Finally, a consistent framework is formulated for obtaining reflectionless solutions corresponding to any number of simple zeros of the analytic scattering coefficients, leading to any combination of bright and dark-bright soliton solutions.
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