Universal Kriging has not until now been used for mapping of geological data in Croatia. However, it is one of the most frequently used methods of Kriging, probably the most adequate in cases when ...the input data is marked by a common trend. That exact feature is often an attribute of deep geological data, and thereby that of structural maps. Mapped surfaces in a row of examples have a structural trend towards one cardinal direction, or a sequence of geological structures, like anticlinorium, is a part of a structural unit of a higher order such as regional monocline. An example is given of geographical trend recognition in e-log Z’ surface spread in Šandrovac Field as well as successful mapping of that marker depth variable by using Universal Kriging.
The advancement of science and computer development enabled the processing and analysis of large amounts of data for which the geostatistical methods have become indispensable when researching and ...presenting the results in a variety of geosciences. One of the most noted and most accurate geostatistical estimation method is the Kriging method, which estimates the value of the analysed variables at unsampled locations. There are several Kriging techniques, while the most widely used is Ordinary Kriging, at the global level, as well as in Croatian geology. Here, Universal Kriging is described, the purpose of its use and the terminology associated with it in order to facilitate the understanding and use of this technique. It is a technique that is most appropriate when the input data is marked by a trend, and as such can often be applied in geology.
Advancement of science and computer development enabled the processing and analysis of large amounts of data for which the geostatistical methods have become indispensable when researching and ...presenting the results in a variety of geosciences. One of the most noted and most accurate geostatistical estimation method is Kriging method, which estimates the value of the analysed variables at unsampled locations. There are several Kriging techniques, while the most widely used is Ordinary Kriging, at the global level, as well as in Croatian geology. Here was Universal Kriging described, the purpose of its use and the terminology associated with it in order to facilitate the understanding and use of this technique. It is a technique that is most appropriate when the input data is marked by a trend, and as such can often be applied in geology.
As a special forest vegetation reserve, the Prašnik rain forest is a highly protected area which owes its protection not only to a unique composition of trees, but also to its geographical position ...and, to an extent, historical events. It is situated on the Sava River left bank, north of the city of Stara Gradiška (cca. 3 km). The study area belongs to the southwestern part of Pannonian Basin, specifically the Sava Depression. The aim of this study was to assess a possible impact of war activities in Croatia (23 years ago) when numerous mines were laid in this region and to establish a major and trace metal baseline concentrations for future investigations. Ten topsoil (S) samples were taken randomly with adjacent vegetation (bark and leaves) at each site. Major and trace metal concentrations were measured for all three types of samples using the ICP method. Analysed soils are composed of quartz, micaceous mineral, 14Å mineral, plagioclase and mixed layer minerals. All metal values in the sample taken from an ex-mine crater are 2-4 times higher compared to other. Generally, positive statistically significant Kendall’s Tau correlation coefficients of trace metals (Cd, Cr, Cu, Ni, and Zn) were found for all combinations of the S (soil), B (bark), and L (leaf) groups. Such results indicate that the war activity have played a certain role in a distribution pattern of soil as well as vegetative trace metal levels.
The Bjelovar Subdepression area in Northern Croatia was analysed, especially the Šandrovac Field that is located in the northern part of the subdepression. In this example, e-log depth marker Z’, ...i.e. the Pannonian and Pontian boundary, was used as an input data. The data were statistically analysed for the entire subdepression from 497 data readings from the regular grid with cell size of 1x1 km that covers the existing palaeostructural map. Then is selected 18 well data within the Šandrovac Field where e-log markers are recognised (an example of a small number of data). They are also read directly for given structural map and mapped using one of the declustering methods known as Thiessen polygon method or Kriging. It is concluded when the mapping includes small number of data, and consequently local uncertainties, the subsurface mapping need to be done on both ways and maps compared.
Napretkom znanosti i razvojem računala omogućena je obradba i analiza velike količine podataka zbog čega su geostatističke metode postale neizostavne prilikom istraživanja i prikazivanja rezultata u ...raznim geoznanostima. Jedna od najpoznatijih i najtočnijih geostatističkih metoda procjene jest metoda krigiranja, koja procjenjuje vrijednosti analizirane varijable na neuzorkovanim smjestištima. Postoje različite tehnike krigiranja, a najčešće korištena jest obično krigiranje, kako na svjetskoj razini, tako i u hrvatskoj geologiji. Ovdje je opisana tehnika univerzalnoga krigiranja, svrha uporabe navedene tehnike te je opisana terminologija vezana za nju s ciljem lakšega razumijevanja i korištenja. Riječ je o tehnici koja je najprimjerenija kada su ulazni podatci obilježeni trendom, a kao takva može se često primijeniti u geologiji.
The Bjelovar Subdepression area in Northern Croatia was analysed, especially the Sandrovac Field that is located in the northern part of the subdepression. In this example, e-log depth marker Z", ...i.e. the Pamionian and Pontian boundary, was used as an input data. The data were statistically analysed for the entire subdepression from 497 data readings from the regular grid with cell size of lxl km that covers the existing palaeostructural map. Then is selected 18 well data within the Sandrovac Field where e-log markers are recognised (an example of a small number of data). They are also read directly for given structural map and mapped using one of the declustering methods known as Thiessen polygon method or Kriging. It is concluded when the mapping includes small number of data, and consequently local uncertainties, the subsurface mapping need to be done on both ways and maps compared.
Univerzalno krigiranje do sada nije korišteno pri kartiranju geoloških podataka u Hrvatskoj. Međutim, radi se o jednoj od češćih metoda krigiranja, vjerojatno najprimjerenijoj u slučajevima kada su ...ulazni podatci obilježeni zajedničkim trendom. Upravo takvo obilježje vrlo je često svojstvo dubinskih geoloških podataka, a time i strukturnih karata. Kartirane plohe u nizu primjera imaju strukturni nagib prema jednoj strani svijeta. Često je niz geoloških struktura, poput antiklinorija, dio strukturne jedinice većega reda poput regionalne monokline. U radu je dan primjer prepoznavanja zemljopisnoga trenda u pružanju plohe EK markera Z’ u polju Šandrovac te uspješnoga kartiranja te plohe, odnosno dubinske varijable, univerzalnim krigiranjem.
Analiziran je prostor Bjelovarske subdepresije na lokalnoj (polje Šandrovac) i regionalnoj razini (cijela subdepresija). Ulazni podatci bile su dubine EK granice Pt/Tg i EK markera Rs7, Rs5, Z', Δ i ...D'. Statistički je analizirano više od sedamsto podataka očitanih s pravilne mreže kojom su prekrivene postojeće paleostrukturne karte, s ćelijama veličine 2x2 km. Kartirano je metodama Thiessenovih poligona (program SAGA GIS) i krigiranja (Surfer). Poligonalna, tj. zonalna procjena uporabljena je kao jednostavna i brza metoda prikaza dubina. Krigiranje je dalo znatno bolje regionalne karte. Obično krigiranje je dokazano u većini slučajeva kao najbolja moguća interpolacija podataka dubine (Pt/Tg, Rs7, Z' i D'), uz najmanje vrijednosti krosvalidacije. Njome su interpolirane karte debljina formacija iz kojih su reinterpretirani neogensko-kvartarni okoliši. Nadalje, unutar pojedinačnih struktura, tehnika univerzalnoga krigiranja određena je kao najprimjerenija interpolacijska metoda, jer je samo u takvim slučajevima bilo moguće izdvojiti jasan linearni trend u pružanju i dubinama promatrane strukture.
The area of Bjelovar subdepression was analyzed at the local (Šandrovac Field) and regional level (the entire subdepression). Input data were depths of Pt/Tg e-log border and Rs7, Rs5, Z’, Δ and D' e-log markers. More than seven hundred data were statistically analyzed. The data were collected in a regular grid that covers the existing paleostructural maps, with cells 2x2 km in size. Mapping was carried out using Thiessen polygon method (program SAGA GIS) and Kriging (Surfer). The polygonal, i.e. the zonal assessment was used as a simple and fast method for displaying depths. Kriging gave significantly better regional maps. Ordinary Kriging has been proved in most cases to be the best possible interpolation of depth data (Pt/Tg, Rs7, Z' and D'), with the lowest cross-validation values. It was used for interpolation of formation thickness maps from which Neogene-Quaternary environments were reinterpreted. Furthermore, within the individual structures, Universal Kriging technique is determined as the most appropriate interpolation method, because it was only possible in such cases to extract a clear linear trend in extent and depths of the observed structure.
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