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Landslide susceptibility assessment on a large scale in the Podsljeme area, City of Zagreb (Croatia)
No full textThe study presents a landslide susceptibility assessment on a large scale in the City of Zagreb (Croatia). The susceptibility analysis was performed using the Weight of Evidence model in the pilot area (21 km 2 ) and applying the obtained weight values for each class of conditioning factors in the study area (130 km 2 ). The input data were LiDAR-based landslide inventory and six conditioning factors derived from 5 m LiDAR DTM, 5 m SfM DEM, and geological and land-use maps. The validation of the susceptibility assessment for the study area was evaluated with a ROC curve, which showed a high prediction rate (AUC = 84.4%), similar to the prediction rate for the pilot area (AUC = 86.9%). Based on the results, it can be concluded that the proposed method for large-scale landslide susceptibility assessment, where susceptibility conditions are defined in smaller pilot areas, can be applied to larger research areas with similar geomorphological and geological conditions
Quantification of intra- vs. inter-row leaching of major plant nutrients in sloping vineyard soils
No full textNutrient leaching from agricultural soils presents an economic loss for farmers and can degrade the quality of the surrounding environment. Thus, leachates from 18 in situ wick lysimeters, installed at 40 cm soil depth at the vineyard hilltop, backslope, and footslope intra- and inter-row area (SUPREHILL Critical Zone Observatory, Croatia) were collected monthly over two years and analyzed for major plant nutrient ions. Our objectives were to quantify nutrient losses via leaching from the hilltop towards the backslope and to the footslope, and to compare leaching from vine plant rows (intra-row) with grassed areas between vine rows (inter-row). We found that the concentrations of nitrate, orthophosphate, and potassium were significantly higher in leachates collected at the footslope as compared to the hilltop and backslope only at intra- and not at inter-row positions, while ammonium was independent of the slope and row positions. The vineyard intra-row is identified as the probable spatial origin of nutrient leaching along the slope, thus confirming spatially different contributions of overall hillslope to major plant nutrients leaching. The experimental field scheme used in this study, which separately analyses vineyard intra- and inter-row, was confirmed to be an adequate approach for optimizing vineyard management practices
Bisectors of conics in the isotropic plane
No full textIn this paper we introduce the concept of a bisector of two curves in an isotropic plane. We study the bisectors of conics and classify them according to their type of circularity. In general the bisector of conics is a quartic, while in the case when both conics are circular, its degree decreases
Short-term forecasting of natural gas consumption by determining the statistical distribution of consumption data
No full textThe development of gas smart meters has enabled the collection of data on daily natural gas consumption which can be used to develop and improve methods and models for natural gas consumption forecasting. This paper presents the development of a model for the short-term forecasting of total natural gas consumption, which is applicable in different distribution areas where smart meters are installed in large numbers. The advantages of this model are the use of only two input parameters (daily natural gas consumption and average daily temperature), forecasting the total consumption in the determined area by analyzing the consumption data of less than 10% of the total consumers as well as robustness to consumer types. Daily natural gas consumption data collected from the more than 3300 gas smart meters over a period of six months was used for the determination of correlations between lognormal distribution variables and temperature. The defined correlations between distribution variables and temperature were used for upscaling consumption to a specific number of final consumers, i.e., to obtain the total consumption of natural gas in the observed area. Best results were achieved using the ‘‘two-day rolling average temperature’’ in the consumption scenario up to 250 m3 per day (MAPE was 7.26%). When compared to using ‘‘average temperature’’ as an input parameter, ‘‘two-day rolling average temperature’’ and ‘‘shaving peaks temperature’’ produced better results due to the mitigated impact of sudden temperature changes that significantly affected the simulated consumption in the model while the actual consumption is a little more inert. Also, consumption scenarios up to 250 m3 can be considered the most representative for forecasting total natural gas consumption since it achieved the best results
Estimation of nitrate background value in groundwater under the long-term human impact
No full textThis study demonstrates an approach to estimate the background value of nitrate as a basis for better groundwater management and protection in areas under long-term human impact. The aim was to determine the ambient background value (ABV) of nitrate in the catchment area of the Velika Gorica well field, a hydrogeologically homogeneous area within the Zagreb aquifer. ABVs are determined using four well-known model-based objective methods (the iterative 2-σ technique, IT; the calculated distribution function, CDF; the cumulative frequency curve, CFC; and the probability plot, PP), while simultaneously testing the reliability of the results of each method. If the results are not statistically significant, data selection is performed. The results show that using data without selection can lead to statistically non-significant ABVs, but with the additional selection of data, a statistically non-significant result became a statistically significant one. In summary, all final ABVs must be statistically significant and determined using as large a data set as possible. Reducing the size of the data set is acceptable only in the case of a statistically non-significant result
Effects of soluble dietary fibre on exercise performance and perception of fatigue in young basketball players
No full textResearch background. In this study, we investigated the effects of soluble dietary fibre on improving neuromuscular and cardiovascular endurance and perception of fatigue in a closely monitored group of basketball players. Prebiotics have been sidelined in sports nutrition and their effect on performance remains poorly investigated and understood.
Experimental approach. Eighteen healthy male basketball players were divided into two groups; one received 17 g/day of soluble dietary fibre (Nutriose®) for four weeks and the other group received placebo. Their morphological characteristics, neuromuscular and cardiovascular endurance, and rating of perceived exertion according to the rating of perceived exertion (RPE) scale were assessed. Measurements were taken before supplementation and after four weeks of supplementation. Faecal samples were collected from all participants immediately before and after the supplementation period, their total DNA extracted and sent for amplicon sequencing.
Results and conclusions. In this study, fibre had no statistically significant effect on the vertical-type explosive power, no statistically significant effect on sprint-type explosive power, nor on aerobic and anaerobic endurance in the experimental group. Soluble fibre had a statistically significant effect on reducing the rating of perceived exertion of basketball players during the competitive part of the season (RPE 7.27±0.04 versus 8.82±0.81). This was confirmed by two-way ANOVA with replication, which showed that within-group interaction (p=0.0193), before and after dietary intake (p=0.0049), and between-group interaction before and after dietary intake (p=0.0313) had a significant effect on the result. The overall conclusion of the study is that soluble dietary fibre supplementation does not improve neuromuscular and cardiovascular endurance over a 4-week period. However, fibre supplementation could have a significant effect on reducing the rating of perceived exertion, as shown by the statistics. Both amplicon sequencing and subsequent bioinformatics results suggest that this could be the result of the beneficial effect on the intestinal microbiota and its metabolites.
Novelty and scientific contribution. This work highlights the importance of prebiotics in sports nutrition. Dietary fibre has been a neglected component of sports nutrition. This study demonstrated a statistically significant positive effect on the perception of fatigue, highlighting the need for further studies in this direction
Comparison of urban and rural soils based on speciation of heavy metals by BCR sequential extraction procedure: a case study in the historical and industrial city of Sisak, Croatia
No full textWithin the framework of the pan-European project “URban GEochemistry (URGE) in Europe – Soil, children, health”, pedological and geochemical investigations of the soils of the city of Sisak and its adjacent surroundings were carried out, and three urban and two rural soil profiles were examined. The mineralogical composition and concentration of selected potentially toxic elements (PTEs) Cr, Cu, Ni, Pb and Zn in the soil were determined. The Community Reference Bureau of Reference (BCR) sequential extraction procedure (SEP) of these PTEs was undertaken and the potential risk to human health and the environment was assessed. The concentrations of Cr and Ni are generally similar in urban and rural soil profiles, while the concentrations of Cu, Pb and Zn in soil horizons/layers are higher in urban profiles. The extracted fractions of PTEs gave the following general distribution: in urban soil profiles residual (RES) > reducible (ORG) or oxidisable (FEMN) > exchangeable (CARB), except for Cu where ORG > RES > FEMN > CARB, while in rural soil profiles RES > FEMN or ORG > CARB, except for Pb where FEMN > RES or ORG > CARB. The differences between soils in urban and rural profiles depend mainly on the historical land use, i.e. on the duration and intensity of anthropogenic influences on the soil and, to a lesser extent, on the geogenic origin of the parent material and the pedogenic processes. The studied elements in the urban soil profiles are predominantly of anthropogenic origin, indicating a possible influence of the ancient settlements of Segestica and Siscia and of heavy industry in the 20th century. The anthropogenic influences on the rural profiles are low and geogenic influences dominate. Risks to the environment were assessed in the soil profiles based on PTE concentrations in the CARB fraction and the sum of the CARB, ORG and FEMN fractions from BCR SEP. All calculated risks to human health and the environment were rated as no-risk, very low risk and low risk
Depositional dynamics of Upper Miocene and Pliocene sediments in the eastern part of Drava Depression : doctoral dissertation
No full textU ovom doktorskom radu analizirane su gornjomiocenske i pliocenske naslage istočne Dravske depresije. Cilj istraživanja je određivanje klinoformi i parasekvencija na temelju interpretacije površinskih seizmičkih mjerenja i podataka iz dubokih bušotina te određivanje starosti naslaga korištenjem metode datiranja autigenih nuklida 10Be/9Be. Pretpostavka je da se sintezom ovih rezultata može dobiti uvid u dinamiku i razvoj okoliša taloženja. Na seizmičkim podacima provedene su seizmostratigrafske analize, analize seizmičke geomorfologije te strukturna interpretacija. Na bušotinskim geološkim podacima provedene su sedimentološke analize, odredbe starosti geokronološkim i biostratigrafskim metodama, a na karotažnim podacima su interpretirane parasekvencije. Zajedničkom interpretacijom svih izvora podataka određene su četiri litostratigrafske jedinice: formacija Medvedski breg (duboko do otvoreno jezero), formacija Andraševec (dubokovodni turbiditi), formacija Nova Gradiška (delta i plitkovodni jezerski okoliši) i formacija Pluska (aluvijalni i fluvijalni). U analiziranim naslagama određeno je pet sekvencija III. reda, koje su sastavljene od osam sekvencija IV. reda. Radiometrijskim datiranjem naslaga utvrđeno je da su jezerski okoliši prevladavali od 11,089 ± 0,549 do 6,713 ± 0,272 mil. god., a kopneni okoliši i prije 4,987 ± 0,161 mil. god. Rezultati analiza pokazuju da je uslijed promjenjivih smjerova taloženja dinamika taloženja bila kompleksna, što je utjecalo na složenu raspodjelu litofacijesa i različite stratigrafske granice između jedinica. Posljedica toga je otežana korelacija manjih sedimentnih tijela i jedinica viših redova na većim udaljenostima ili korištenjem samo jednog izvora podataka. Na dugoročni razvoj taložnog sustava, odnosno razvijanje sekvencija III. reda, dominantno je utjecala klima, subsidencija i tektonika, odnosno strukturni sklop o kojem je ovisila morfologija depresije. Na razvoj sekvencija IV. reda utjecale su periodične izmjene vlažne i suhe klime te unutarnji mehanizmi taložnog sustava. Rezultati i metode istraživanja primjenjivi su u analizama geoenergetskih resursa, od još neotkrivenih akumulacija nafte i plina, geotermalnog potencijala, mogućnosti skladištenja ugljikovog dioksida do skladištenja energije ili vodika u dubokom podzemlju.The focus of this research is on the Upper Miocene and Pliocene sedimentary infill in the eastern part of the Drava Basin. The mentioned area has been continuously subjected to oil and gas exploration for more than 70 years; however, the ages of the final sedimentary filling, disappearance of the lacustrine environments, and subsequent development of delta plain and terrestrial environments have not been precisely estimated. In light of the proposed theme, the research aims to determine the clinoforms and parasequences in analyzed deposits because such units can most adequately depict the most important palaeogeograpy and depositional environments. Furthermore, the absolute age of deposits can be resolved using the authigenic nuclides 10Be/9Be dating method, while biostratigraphic analyses determine the relative age and facies. Through the data synthesis and interpretation, an attempt will be made to reconstruct the development of paleoenvironments and paleogeography in as much detail as possible, as well as to distinguish the main external and internal factors that influenced the dynamics of the Late Miocene and Pliocene sedimentation in the study area. For this purpose, seismic reflection and borehole data were used. Specifically, the deposits were analyzed by seismostratigraphic approach; seismic geomorphology and structural analyses which were performed on the seismic data. Sedimentological analyses and absolute age determinations were performed using geochronological and biostratigraphic methods on the well-core data. The cycles and parasequences were interpreted on the well-log data, from which the schematic geological columns were made. Data integration enables the separation of environments, lithostratigraphic units, inside which sequences were interpreted. The depth, structure, and thickness maps were made for each sequence. The analyzed sequence is composed of four lithostratigraphic units: Medvedski breg fm. (shallow to the deep open lake), Andraševec fm. (deep-water and slope-toe turbidite system), Nova Gradiška fm. (deltaic to shallow water lacustrine) and Pluska fm. (alluvial and fluvial). Three phases of third-order sequences inside the Lake Pannon lacustrine deposits were distinguished. The development of the third-order sequences was generally controlled by the ratio of accommodation and sediment supply, or more precisely, the interplay between the subsidence, climate variations, and possibly tectonics. Each unit is composed of fourth-order vi sequences or parasequences sets that can also be interpreted as regressive and transgressive system tracts in classical sequence stratigraphic terms. The results show that the deposition dynamics were rather complex due to changing sedimentary system directions affecting the complex lithofacies distribution and the stratal stacking patterns. This is especially emphasized in the evolution of the third sequence of the overfilled lake, where sediment input direction was frequent due to lateral switching of deltaic lobes. The authigenic nuclides 10Be/9Be dating method results reveal that the lacustrine environments prevailed from at least 11,089 ± 0,549 Ma to 6,713 ± 0,272 Ma. The subsequent terrestrial environments were developed well before 4,987 ± 0,161 Ma. The long-term, third-order evolution of the depositional system was dominantly influenced by climate, subsidence, and tectonics, and especially the structural relations that influenced the morphology of the depression. Periodic changes in wet and dry climates and internal mechanisms (e.g., frequent avulsion) controlled the development of fourth-order sequences. As a result, it is challenging to correlate smaller-scale sedimentary bodies or units of higher orders at greater distances or using a single data source (e.g., well data). The results and research methods are applicable in analyzing various geo-energy resources, especially in understanding the role of the strike variability in reservoir correlation
Usporedba digitalnog modela terena iz topografske karte mjerila 1:25 000 i SRTM satelitske misije na području Makarske : završni rad
No full textU ovom završnom radu su opisani SRTM i DMR modeli terena. Opisan je geografski informacijski sustav, što je u njemu najbitnije, koja je njegova svrha i program QGIS u kojem su obrađivani rezultati. Svrha izvođenja analize je bila da se vidi koja su međusobna odstupanja između SRTM-a i DMR-a. Detaljno je opisan cijeli postupak i svaki korak o provjeri podataka. Iznesen je osobni stav na provedenu analizu i kako bi se ona mogla poboljšati
Analiza gibanja klizišta Kostanjek na temelju GNSS podataka : završni rad
No full textZavršni rad sastoji se od općenitih podataka o klizištu Kostanjek kao i povijesti i nastanku samog klizišta. Drugi dio završnog rada fokusiran je na prikaz podataka GNSS-a 08. Podaci su prikazani pomoću grafova koji prikazuju pomake S-J, I-Z, vertikalni i horizontalni pomak kao i brzini kretanja. Na temelju podataka zaključeno je kako se klizište kreće prema jugo-jugozapadu uz povremena odstupanja pri kutu od 188º. Tijekom gibanja bilo je 8 perioda s većim brzinama kretanja klizišta. Uz izračun pomaka izračunate su i pogreške prilikom mjerenja koje u horizontalnom smjeru iznose ±3,11 a u vertikalnom smjeru ±6,71. Na temelju podataka pretpostavljeno je kako do bržih kretanja klizišta dolazi u hladnijim i kišnijim razdobljima godine te bi tada trebalo očekivati mogućnost nastanka veće štete i bit spremni za sanaciju