Zoran Kovač

Gaussian simulation of nitrate concentration distribution in the Zagreb aquifer

ABSTRACT Nitrates present one of the most common groundwater contaminants in the world and one of the five major groups of contaminants in the study area. Gaussian simulation (GS) algorithm was used for determining the spatial distribution of average nitrate concentrations from 2010 to 2015 on 95 sampling points. Results indicate two main focus areas of nitrate contamination, located on the left and right bank of the Sava River. Those areas generally extend according to groundwater flow, while areas near Sava River have much smaller concentrations. GS showed that they can be useful for this kind of mapping because they favor abrupt changes in data values which are in this case a result of heterogeneous lithological composition of the aquifer.

Environmental geology and hydrology

Abstract Environmental geology is scientific discipline dealing with the interactions between humans and the geologic environment. Many natural hazards, which have great impact on humans and their environment, are caused by geological settings. On the other hand, human activities have great impact on the physical environment, especially in the last decades due to dramatic human population growth. Natural disasters often hit densely populated areas causing tremendous death toll and material damage. Demand for resources enhanced remarkably, as well as waste production. Exploitation of mineral resources deteriorate huge areas of land, produce enormous mine waste and pollute soil, water and air. Environmental geology is a broad discipline and only selected themes will be presented in the following subchapters: (1) floods as natural hazard, (2) water as geological resource and (3) the mining and mineral processing as types of human activities dealing with geological materials that affect the environment and human health.

Hydrogeological characteristics of south hills, Ivanščica Mountain

ABSTRACT This article presents results of hydrogeological and hydrogeochemical research conducted at south hills, Ivanščica Mountain, situated in the northwestern part of the Republic of Croatia. Research was carried out in the summer 2013, between July and September. Hydrogeological mapping was undertaken on approximately 20 km2 (at a scale of 1:25000), with water samples taken from 10 springs. Rocks and deposits were classified into three hydrogeological units with respect to permeability. Two main aquifers were identified – the Triassic carbonate aquifer and the Badenian carbonate aquifer. The overall capacity of 41 registered springs (permanent and periodic) was estimated. According to their basic chemical composition, water from springs belong to Ca-HCO3 (calcium-hydrogen carbonate), CaMg-HCO3 (calcium magnesium-hydrogen carbonate) and to MgCa-HCO3 (magnesium calcium-hydrogen carbonate) types.