The Protection of Karst Aquifers: the Example of the Bistrica Karst Spring (SW Slovenia)

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

Hydrogeological study of the Malenščica karst spring (SW Slovenia) by means of a time series analysis

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

Sediment production in flysch badlands: A case study from Slovenian Istria

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

An Attempt Towards an Assessment of the Cerknica Polje Water Balance

This paper deals with the water balance of the Cerknica Polje. The results of previous investigations are compared with the calculations of inflows to and outflows from the polje made for the hydrological year 1975 (411 days). The calculation of the Cerknica Polje water balance is made on the basis of daily volume variations of Lake Cerknica, calculated using the water level data of the Stržen stream at the Dolenje Jezero gauging station and the digital elevation model of the Cerknica Polje (grid cell size 25 x 25 m). For the hydrological year 1975, total runoff from the Cerknica Polje catchment (475 km2) is estimated at 620 million m3 of water or 17 m3/s. In the observation year, the strongest lake volume increase in terms of discharge was 135 m3/s, whereas the strongest lake volume decrease was 60 m3/s. According to calculations, maximum possible inflow to the Cerknica Polje was 232 m3/s. In the hydrological year 1975, calculated mean outflow from the Cerknica Polje through ponor caves and ponors at the bottom of the polje was 23.69 m3/s and maximum calculated outflow was 91.75 m3/s

Deformations of Gabor Frames

The quantum mechanical harmonic oscillator Hamiltonian generates a one-parameter unitary group W(\theta) in L^2(R) which rotates the time-frequency plane. In particular, W(\pi/2) is the Fourier transform. When W(\theta) is applied to any frame of Gabor wavelets, the result is another such frame with identical frame bounds. Thus each Gabor frame gives rise to a one-parameter family of frames, which we call a deformation of the original. For example, beginning with the usual tight frame F of Gabor wavelets generated by a compactly supported window g(t) and parameterized by a regular lattice in the time-frequency plane, one obtains a family of frames F_\theta generated by the non-compactly supported windows g_\theta=W(theta)g, parameterized by rotated versions of the original lattice. This gives a method for constructing tight frames of Gabor wavelets for which neither the window nor its Fourier transform have compact support. When \theta=\pi/2, we obtain the well-known Gabor frame generated by a window with compactly supported Fourier transform. The family F_\theta therefore interpolates these two familiar examples.Comment: 8 pages in Plain Te

Mapping of Hazards to Karst Groundwater on the Velika Planina Plateau

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.