Journal of the Geographical Institute "Jovan Cvijic" SASA - Geographical Institute "Jovan Cvijic"
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TORNADO FREQUENCY IN THE USA — METEOROLOGICAL AND NON-METEOROLOGICAL FACTORS OF A DOWNWARD TREND
Get PDFCiting numerical simulations, climate alarmists believe that global warming will lead to more frequent and more intensive tornadoes. Considering temperature increase data in the contiguous USA, this study has investigated the trend of strong tornadoes in F3+ category in the 1954–2012 period. Statistically significant decrease of tornadoes per year at an average rate of 0.44 has been recorded, that is, 4.4 tornadoes per decade. Tornado increase has been recorded with F0 and F1 categories and the cause of this increase lies in meteorological and non-meteorological factors. By using upper and lower standard deviation values, the stages of tornado activity have been singled out. The 1957–1974 period may be considered as an active stage and the 1978–2009 period as an inactive stage. Upward trend of air temperature increase does not correspond with the downward trend of the number of F3+ tornado category, while the correlation coefficient between these two variables is R = -0.14. This fact does not correspond with the simulation results and output data of various numerical models anticipating an increase in the number and intensity of tornado events in the conditions of surface air temperature growth
STORM ON JUNE 22, 2013 IN INDJIJA (SERBIA) – A CONSEQUENCE OF HEAT WAVE
Get PDFIn the period between 16 and 22 June 2013, Europe was hit by a heat wave. At the end of the period characterized by extremely high temperatures, the development of storm along with supercell HP convection cell took place in Serbia, producing tennis ball-sized hailstones and wind with speed exceeding 35 m/s. This paper analyzes the underlying conditions that led to development of this storm using synoptic charts, vertical atmosphere characteristics as well satellite and radar images. The development of strong convective clouds was enabled by exceptional thermal instability of the atmosphere above the Pannonian Plain and the Balkans and warm subtropical air. The analysis of the vertical structure of atmosphere indicates that the separate convective cells could produce large amounts of precipitation and hailstones up to 8 cm in diameter. Cloudy zone, of the supercell type in development, of 12–16 km width, reached to 20 km height (cloud penetrated tropopause) and indicating extremely great energy instability. Furthermore, this analysis is supplemented with results of nonhydrostatic mesoscale NMM model. Big hailstones from this storm took life of 31 persons in addition to great material damage it caused
THE LIFE AND WORK OF TOMISLAV RAKIĆEVIĆ
Get PDFAfter the Second World War begins the rapid development of the scientific geography and climatology, the discipline whose pioneer was in the first half of XX century Pavle Vujević, attracts a number of researchers. Tomislav Rakićević, professor at the Faculty of Geography, University of Belgrade, has dedicated its researches to this discipline of physical geography throughout his career, giving it special focus since the 70’s with only occasional researches in his primarily field of hydrogeography. This paper concerns with the life and work of Tomislav Rakićević, his scientific development, professional engagement, researches, fields of interest, influences of his work, participation in various conventions but also with his pedagogical activities, devotion to bring science closer to the public and his work on the popularization of science. Among the honours he received, the “Jovan Cvijić” medal is of the special importance. The paper includes the comprehensive bibliography of published works after 1990, the first of its kind
KARST GROUNDWATER BUDGET AND DISCHARGE REGIME OF BANJA SPRING NEAR PETNICA
Get PDFDetailed hydrological and hydrogeological assessments of karst spring discharge require information about the groundwater regime in the study area/watershed. However, groundwater regime monitoring is often organized locally and sporadically, as required for specific studies or projects, and seldom lasts longer than one year. On the other hand, if time series of quantitative parameters are shorter than 15 years, the watershed is considered to be ungauged. As a result, discharge regime and karst aquifer budget assessments of ungauged watersheds can be misleading. To minimize water budget assessment errors, available time series need to be extended as far as possible. Regression models are commonly used to extend, simulate or fill gaps in existing time series. The paper presents an application of multiple linear regression to extend the existing time series of mean monthly discharges of Banja Spring (at Petnica, western Serbia), in order to cover the entire study period (1960-2006)
ETHNIC “BAROMETER”: ETHNO-DEMOGRAPHIC AND ETHNO- MIGRATION PROCESSES IN THE NORTH CAUCASUS
Get PDFOne of the main causes of social tension in the North Caucasus is the reduction in the Russian population. Modern GIS technology can be applied when analyzing the geography of settlement, demographic and migration trends from the Russians. “Russian” municipalities of the North Caucasus have a high growth rate is negative features of the demographic and migration processes that can lead to a significant reduction of the area of settlement of Russians in the region
CHANGES IN LAND COVER/LAND USE OVER THE NORTHEAST REGION OF INDIA
Get PDFThe Northeast region (NER) is rich in biodiversity however it is under increasing pressure due to economic development. With this in backdrop, an attempt is made to investigate the trend in forest cover, shifting cultivation and urbanization. The analysis reveals that annual forest cover shows significant decreasing trend at Nagaland and Manipur while increasing trend is reported at six states. In order to understand the causative factor for increase/decrease, the data related to various forest cover viz., dense, open, scrubs and non-forestland were collected and analysed. The result indicates that except Arunachal Pradesh and Assam, the rest of the state reported increase in dense forest cover. The analysis also shows that area under shifting cultivation has decreased considerably across the NER. This can be ascribed to the afforestation drive, settled agriculture and social forestry etc. In NER, all the major towns show exponentially increase in population growth significant at 99%. Thus, there is a positive correlation between population growth with that of forest cover and urbanization unlike shifting cultivation. The results also show significant decrease in monsoon rainfall and an increase in temperature variables, a part played by change in land cover and land use
LEISURE TIME AND MUSEUMS - MOTIVES OF VISITS
Get PDFLeisure time, as the time used to engage in a variety of activities, should provide a sense of satisfaction and relaxation. In order to satisfy the needs of the visitors and their desire to experience something new and authentic in tourist destination, it is very important to know what their choices are with regard to leisure activities. The aim of this paper is to determine how museum public usually spends its leisure time, which factors influence the motivation to visit museums, and to try to find a correlation between the two. The paper is based on the results of the study conducted between the end of May and the end of August, 2014 in the museums in Vojvodina Province (northern part of the Republic of Serbia). The main findings of this paper indicate that spending leisure time is primarily related to socialization and education, and that museums are visited mostly due to their educational role. The findings also indicate that there are differences between the choice of leisure activity and motivation for visiting museums and sociodemographic characteristics of the respondents. Significant correlation has been found between the choice of leisure activity and motivation for visiting museums
ASSESSMENT MODEL OF NATURE-BASED TOURISTIC MOTIVES OF THE OVČAR-KABLAR GORGE (SERBIA)
Get PDFOne of the initial stages of the tourist development is the assessment of the elements or the entire area in order to identify priorities that will continue to be presented and economically valorised through specific measures and activities. This is possible to achieve by using different models of evaluation with a tendency to more qualitative characteristics express quantitatively. The idea is to develop a universal model that can be applied to different areas in order to be comparable with each other, so decision-makers knew exactly which one of the areas has greater potential to develop tourism. This paper presents the model of evaluation of nature-based touristic motives that was created by combining several adapted methodologies. The proposed model is applied to the area of Ovčar-Kablar Gorge (Western Serbia). After the process of evaluation, it turns out that natural elements of Ovčar-Kablar Gorge have moderate importance to the development of tourism and that with concrete measures in the field of nature protection and planning of the tourist area, this status can be improved
ANTHROPOLOGY OF MIGRATION: THE EXPERIENCE OF THE DOUKHOBORS IN CANADA
Get PDFUntil recently, practically no attention was paid to the ethnic composition of the Doukhobors, since there has been established an idea of the Doukhobors as a special group of the Russian ethnos. Few studies mentioned about the ethnic heterogeneity of the Doukhobors, uniting not only Russians, but also the Mordvins, Poles, Gypsies, Tatars, Ukrainians, etc. Doukhobors’ ideology contributed to the fact that in their communities as in a kind of melting pot, representatives of various ethnic groups became one. The Doukhobors believe in their special mission, considering themselves as a separate ethnos and requiring recognition of this position not only from the surrounding population, but also from the state authorities. However, despite many common characteristics of all Canadian Doukhobors that have arisen on the basis of a common religious cult and joint activities, one language (Russian) and genesis, Doukhobors of the Mordovian origin, long living outside their historic homeland, still remember about the ethnic roots, retaining some features of the traditional Mordovian culture
RELIABILITY OF INTERNET SOURCES IN GEOGRAPHY: CASE STUDY OF MOUNTAINS STUDENA AND ŽARAČKA, SERBIA
Get PDFJovan Cvijić said that geography is learned on foot. Besides fieldwork, the modern studies imply the usage of various software packages, as well as the data sources available from the Internet. All the data acquired from the Internet need to be carefully checked, unless they are retrieved from the websites of the established formal institutions (Government, Institutes, and Offices). Very often the Internet information may be in the form of data which should be additionally processed by using mathematical and statistics methods. Possibilities for Internet usage will be shown through presentation of the relief characteristics of the mountains Studena and Žaračka, which belong to Kopaonik system. They make a connection between Mt. Goč and Mt. Stolovi in the north and the massif of Mt. Željin and Mt. Kopaonik in the south. Taking into consideration that Mt. Studena and Mt. Žaračka were not previously studied by geographers, this paper is the contribution to the knowledge on these mountains