Hydrogeological investigation of landslides Urbas and Čikla above the settlement of Koroška Bela (NW Slovenia)

The area above the settlement of Koroška Bela is highly prone to slope mass movements and poses a high risk for the safety of the settlement. To get an insight into the hydrogeological conditions and processes which can affect mass movements in this area, hydrogeological investigations, including hydrogeological mapping, discharge measurements of springs, performance of infitrometer and slug tests were performed. The results of these investigations show complex and heterogeneous hydrogeological conditions, predisposed by geological and tectonic setting and active mass movements which cannot be uniformly described. Observed large flctuations in the rate of discharge of springs and groundwater level in observation wells are highly dependent on meteorological conditions. Estimated hydraulic conductivity of the soil is relatively high (2×10 -4 m/s) and reflcts the loose structure and high content of organic matter in the upper part of the forest soil. Hydraulic conductivity of more permeable sections of boreholes is in general higher in the upper parts, in predominantly gravel layers (in range from 2×10 -3 to 1×10 -5 m/s), than in the deeper clayey gravel parts (3×10 -5 to 1×10 -7 m/s). In the area of the Čikla landslide the average hydraulic conductivity is estimated at 8.99×10 -4 m/s and is higher than in the area of the Urbas landslide (3.05×10 -4 m/s)

Skrb za pitno vodo

Safeguarding Drinking WaterLjubljana's water resources lie in the immediate vicinity of built-up urban areas or even below them. For decades, they have been safeguarded as water-protection areas, which are specified by implementing regulations. However, formal protection through regulations is insufficient if the goal is to manage these sources in a sustainable manner. One of the most important goals of sustainable management is maintaining suitable provision of fresh drinking water without using any technological procedures toVodni viri mesta Ljubljane so v neposredni bližini pozidanih mestnih zemljišč ali celo pod njimi. Že desetletja jih varujejo vodovarstvena območja. Eden od najpomembnejših ciljev trajnostnega upravljanja je ohranjanje ustrezne oskrbe z naravno pitno vodo brez tehnoloških postopkov njene priprave, kar Ljubljančani uvrščajo visoko na lestvici vrednot življenja v glavnem mestu Slovenije. Upravljanje ogroženih vodnih virov v urbanih okoljih zahteva celosten pristop in stalne aktivnosti. S pomočjo računalniških orodij znamo sisteme simulirati in tako pridobiti dodatna védenja o njihovem delovanju. Ta so v pomoč pri dolgoročnih odločitvah ali na primer ob okoljskih nesrečah. Za ustrezno načrtovanje so potrebna strokovna orodja, ki omogočajo zanesljive, pregledne in kvantitativne ocene učinkov ukrepov. Razpolaganje z zanesljivimi ocenami stanja in napovedmi olajšuje delo odločevalcem in tudi komunikacijo med deležniki. Povezava v monografiji predstavljenih postopkov in rezultatov v sistem izvedljivega upravljanja z vodnimi viri v Ljubljani je dosežek, ki je lahko zgled številnim podobnim okoljem, ne le v Sloveniji, ampak tudi širše

Perched aquifers spatial model: a case study for Ljubljansko polje (central Slovenia)

Ljubljansko polje aquifer is one of the biggest and most important aquifers in Slovenia. In general it is an unconfinedaquifer, but locally, on the SW part, layers with low hydraulic conductivity appear and on those areas perchedaquifers are formed. Based on lithological data from boreholes (emphasizing hydraulic conductivity of lithologicalunits) and use of geostatistical method Sequential Indicator Simulation (SIS) hydrogeological model of westernpart of Ljubljansko polje was made. In the model layers with hydraulic conductivity K < 10-6 m/s and area largerthan 0.07 km2 were defined as potential areas of perched aquifers. The majority of them are located on the foothillsof Šišenski and Grajski hrib

The three-dimensional regional geological model of the Mura-Zala Basin, northeastern Slovenia

The Mura-Zala sedimentary Basin is a Neogene basin with many competing geopotentials, spanning parts of Slovenia, Austria, Croatia and Hungary. Here we present the 3D regional geological model of the Slovenian part of the Mura-Zala Basin, which was developed to integrate the latest information on the geological structure of NE Slovenia and to publish the model in an open-access mode for easier and faster assessment of geopotentials. This was achieved through the harmonisation of the legacy geological models, the reinterpretation of 145 borehole logs, the construction of the 3D numerical geological model in JewelSuiteTM, and delivering it into a 3D-Explorer environment. The model comprises nine lithostratigraphical units. The Pre-Neogene basement rocks are covered by the Haloze Formation; the Špilje Formation – Badenian and Sarmatian; the Lendava Formation – turbidites and slope; the Mura Formation – delta front and delta plain; and the alluvial Ptuj-Grad Formation. The model has two principal shortcomings, related to currently unavailable seismic reflction data faults were not implemented, and the Quaternary formations were not delimited. The model is useful for regional-scale studies and may reduce geological risks related to exploration in NE Slovenia. It will also support a better assessment of geopotentials and a more feasible approach to their development, and, eventually, will enable the harmonized management of our subsurface in 3D space. This can be achieved using the 3D-Explorer platform which enables the creation of arbitrary vertical cross-sections, horizontal slices and virtual boreholes

POTENTIALLY TOXIC ELEMENTS IN THE DRAVINJA RIVER SEDIMENTS7 (EASTERN SLOVENIA)

The Dravinja river is an important ecosystem and water resource for the Dravinja valley. A great15 part of the valley is under Natura 2000 protection which aims to protect and preserve natural environment and biodi-16 versity. Besides the Natura 2000 programme management, the river has been under increasing environmental pressures,17 among them the potentially toxic elements (PTE) contamination due to the rapid population growth, social economy,18 urbanization, and intensive agriculture activity. This study investigated the contents of selected PTEs (V, Cr, Ni, Cu,19 Zn, As, Mo, Cd, Sb, Ba and Pb) in the Dravinja river surficial sediments. The results show that seven out of eleven20 PTEs were above the allowable and warning limits. The distribution of PTEs may be influenced by the geological21 background composition to some level but more presumably by the anthropogenic activities such as wastewater dis-22 charges, industry and intensive agriculture

Research of the geological and geothermal conditions for the assessment of the shallow geothermal potential in the area of Ljubljana, Slovenia

Shallow geothermal energy is a renewable source of energy. Using it provides benefis for climate, health and economy. A prerequisite for its effiient and sustainable use is the knowledge of its potential as well as the barriers that limit its use. The paper presents the preliminary results of research carried out within the GeoPLASMACE project for the assessment of the shallow geothermal potential in the area of the City of Ljubljana. By compiling existing geological data and fild work, a detailed geological map of the study area was elaborated. The spatial distribution of thermal conductivity was estimated with measurements of thermal conductivity on 47 representative samples of 18 lithostratigraphic units and fild measurements in unconsolidated sediments at 12 localities. The measured values range between 0.63 and 5.18 Wm-1K-1. Continuous groundwater temperature measurements in 17 observation wells with depth to 118 m show relatively small temperature changes over time of 5 months. The measured values on the Ljubljansko polje range between 10.6 °C and 14.6 °C, while in the Ljubljansko barje the temperature increases up to 15.6 °C. Multi-level groundwater temperature measurements in 9 observation wells indicate three different conditions: both negative and positive temperature gradients and a constant temperature in different depths of the aquifer, which reflcts the deeper geothermal or hydrogeological conditions and the anthropogenic impact

The assessment of the required groundwater quantity for the conservation of ecosystems and the achievement of a good ecological status of surface waters

Assessment of the available quantity of groundwater is of essential importance for its sustainable use. Modern approaches for estimation of groundwater availability take into account all potential impacts of abstractions, including impacts on groundwater dependent ecosystems and impacts on surface waters ecological status. Groundwater body is in good quantitative status if groundwater abstractions do not cause signifiant damages to groundwater dependent ecosystems and signifiant diminution in the ecological status of surface water bodies. The methodology presented in this paper was developed as an integral part of the assessment of the quantitative status of groundwater bodies in Slovenia and is tailored to the characteristics of the groundwater dependent ecosystems as well as hydrological and hydrogeological conditions in the Slovenian territory. Two different approaches were implemented; for forest habitats on alluvial aquifers, and habitats of amphibians and molluscs in karst areas. Estimates of the required quantity of groundwater for groundwater dependent ecosystems conservation were performed at the level of groundwater bodies and annual averages of temporal variables of the water balance, calculated with the regional water balance model GROWA-SI. In the areas of groundwater bodies with groundwater dependent ecosystems estimated quantity present 0.1 % - 12.4 % of the groundwater recharge. The estimated share of annual renewable quantity of groundwater to maintain the ecological status of surface waters for the entire territory of Slovenia is 23.2 %. The largest share, 30 % is in north-eastern Slovenia and the lowest in the north-west part of Slovenia with a 16.6 % average annual renewable quantity