Methods for assessing the chemical status of groundwater in the Pomurje region

Kvartarni vodonosniki na obmo%ju Pomurja so med najbolj ranljivimi in onesnaţenimi v Sloveniji. Na ranljivost in onesnaţenost vodonosnikov poleg %lovekovih vplivov v veliki meri vpliva tudi geološka zgradba. V magistrski nalogi sem na primeru Pomurja izvedla univariatne in bivariatne statisti%ne analize, geostatisti%no analizo ter ocenila kemijsko stanje podzemne vode. Statisti%no sem analizirala spremenljivke vodnega kroga za obdobje 1992-2008. Geostatisti%na analiza temelji na debelinah in litologiji slabše prepustnih plasti, ki leţijo na dobro prepustnem kvartarnem vodonosnem peš%eno prodnatem zasipu reke Mure in njenih pritokov. Rezultati kaţejo, da imajo vrhnje slabše prepustne plasti velik vpliv na onesnaţenje vodonosnikov v Pomurju. Vplivajo na variabilnost spremenljivk, na njihove medsebojne odnose in na kemijsko stanje podzemne vode. Najbolj variabilne so spremenljivke, ki opisujejo kakovost podzemne vode. Debeline in litološke zna%ilnosti vrhnjih slabše prepustnih plasti narekujejo hidrodinami%ne zna%ilnosti vodonosnika. Odprti vodonosnik, ki v osrednjem delu Pomurja prehaja v polzaprtega je najbolj ranljiv in onesnaţen. Na fizi%nih mejah je polzaprti vodonosnik manj ranljiv in manj onesnaţen, debeline vrhnjih slabše prepustnih plasti so ve%je. Analiza linearnih trendov je za obravnavano obdobje pokazala, da se vsebnosti onesnaţeval zniţujejo, kemijsko stanje podzemne vode v Pomurju se izboljšuje.The quaternary aquifers in the Pomurje region are among the most vulnerable and polluted in Slovenia. In addition to human impact, the vulnerability and pollution of aquifers depend on the geological composition. In the master\u27s thesis, univariate and bivariate statistical and geostatistical analyses were used and the chemical status of groundwater was assessed in the Pomurje region. Data on water cycle variables for the period 1992-2008 were statistically analysed and evaluated. The geostatistical analysis was based on the thicknesses and lithology of low permeable layers, which lie on the quaternary sandy -gravely highly permeable aquifer, deposited by the Mura river and its tributaries. The results indicate that upper low - permeable layers have a great impact on the pollution of aquifers in the Pomurje region. They affect the variability of variables, relationships between them, and the chemical status of groundwater. Variables of groundwater quality show higher variety. The thicknesses and lithological characteristics of these layers dictate the hydrodynamic characteristics of the aquifer. Unconfined aquifer, which is transitioning into leaky aquifer, is the most vulnerable and polluted in the central part of Pomurje region. On the aquifer\u27s lateral boundaries upper low - permeable layers are thicker. The extent of groundwater pollution is reduced, concentrations of pollutants are lower. The analysis of linear trends has shown that pollutants concentrations are decreasing for observed period, and the chemical status of groundwater in the Pomurje is improving

Establishment of a freely accessible GIS database containing the results of groundwater tracing and possibilities of its use

Tracing with artificial tracers is a research method that gives very good results in examining the direction and characteristics of groundwater flow in karst aquifers. The first mention of such experiments in Slovenian karst dates back to history and the beginnings of their use in the water resources management process in the first years of the 20th century. From that point on, more than two hundred tracer tests were carried out in Slovenian karst. Unfortunately, their results often remain hidden in internal reports in the archives of implementing organisations and are very difficult to access. The search for published results is also a time-consuming process, despite the possibilities of the use of search engines and key words. Due to the need for a systematic and rapidly accessible digital inventory of the tracer tests results, such inventory was designed and is now freely accessible in the Environmental Atlas (Atlas okolja), the spatial information system of Slovenian Environment Agency. In the database the results of 231 available tracer tests have been assembled, arranged and georeferenced. The article describes the data set concept, the process of collecting, verifying and evaluating data and the method of their transformation into a GIS database. Two points layers (injection site and sampling site) and one line layer (linear connection between both sites) were created. Symbology of line layer varies with different type of connection between injection and sampling site. By clicking on an individual element, selected data on the tracer test are displayed, and most of them are also accompanied by a copy of the data source (articles, reports). In this way it is possible to obtain more detailed information about the tracer test and its results. The database also provides a possibility of various comparative analyses. The article shows results of some of the basic statistical analyses in which the purpose and implementation of tracer tests, used tracers, characteristics of injection and sampling sites, and characteristics and velocities of groundwater flow connections were compared. It also provides an overview of the results of the tracer tests carried out within individual groundwater bodies. On the basis of the status identified, the locations for new tracer tests are proposed