2235 research outputs found
Sort by
Forest fires in Portugal - the connection with the atlantic multidecadal oscillation (AMO)
Get PDFThe data on forest fires in Portugal in the period 1980-2015 were used in the research: the annual number of forest fires, the annual burned area and the average burned area per fire. Increasing trend of the annual number of forest fires (statistically significant at p lt = 0.01), nonsignificant increasing trend of the annual burned area and decreasing trend of the average burned area per fire (statistically significant at p lt = 0.01) were recorded. Portugal is the most endangered country by forest fires in comparison with the other European countries. During the research period, fires in Portugal covered 23.6% of the total burned area in five the most affected European countries (Portugal, Spain, France, Italy and Greece). In the research of the connection between forest fires and the Atlantic Multidecadal Oscillation (AMO) Pearson correlation coefficient (R) was used. Monthly, seasonal and annual values of the AMO index were used in calculations. All R values recorded for the annual number of fires were positive and statistically significant at p lt = 0.01. The highest values were recorded for August (0.543) and for summer (0.525). With the annual burned area all R values were also positive and the highest one on the seasonal level was for summer (0.359). With the average burned area per fire all R values were negative (-0.428 was recorded for winter). The results of the research could be applied in the fire danger forecast for periods of several months. Other climate indices should also be considered in future research
Functional role of different habitat types at local and landscape scales for aphids and their natural enemies
No full textThe functional roles of different habitats may depend on the combined effect of local habitat management and the structure and composition of the surrounding landscape. However, this interaction is not well understood due to the common practice of pooling many different habitat types in one simple landscape metric (e.g., percentage crop area). In this study, we investigate the interactive effects of local and landscape factors on the abundance and species richness of aphids and their natural enemies, as well as primary parasitism and hyperparasitism rates. We selected 41 fields in Central Serbia with three disturbance levels at the local scale (wheat fields, alfalfa fields, and fallows) embedded in 15 landscapes that varied in percentage of annual crops, grasslands, and shrublands. We found ecosystem disservices to be promoted in wheat fields, where both aphid abundances and hyperparasitism rates were approximately threefold higher than in alfalfa fields and fallows. Concurrently, alfalfa fields supported at least twofold higher primary parasitism rates and predator (coccinellid) abundances than either wheat fields or fallows. The proportion of grasslands in the surrounding landscape had no effect on any organism group while shrublands appear to be important for both polyphagus predators and pests in some crops, a pattern not revealed when all semi-natural habitats in the landscape are pooled together. Our results imply that the roles of different habitat types at both local and landscape scales should be considered in a multifunctional agricultural management approach, which if adopted may provide better ecosystem services for multiple agroecosystem types
Environmental changes in the city of Pančevo
Get PDFPančevo is an old industrial center in the Banat region. The development of industry and the environment in this city are in the causa - effect relationship: industrialization follows increased degradation of the environment. This relationship was particularly disturbed in the second half of the 20th century, after the construction of a large chemical and petrochemical industrial complex, on the city periphery. The development of industry has negatively affected all elements of city environment. The saturation of air with harmful substances such as benzene, ammonia, sulfur dioxide, soot and suspended particles has become a daily occurrence. Increased concentration of harmful substances in the air directly affects the pollution of the soil - the most important natural resource of Pančevo. A chronic problem of excessive pollution of the surface waters is a consequence of insufficiently built and inefficient sewage system, as well as insufficiently purified industrial water discharged into the recipients. Also, it is necessary to conduct a complex and multidisciplinary research on the long - term consequences of the NATO bombardment, because the amount of harmful substances have melt in the water, air and soil during the two and a half months in 1999, indicate a significate negative changes in the environment of Pančevo
Бујичне поплаве као фактор ризикa за путну мрежу Србије
No full textБујичне поплаве су елементарна непогода , која се најчешће јавља у Србији. Бујични токови и бујичне поплаве се јављају као последица интензивних процеса ерозије земљишта у сливу. Као резултат природних услова, практично цела територија Србије нападнута је водном ерозијом различитог интензитета. Према подацима из катастара бујица урађених средином XX века, више од 12.000 бујичних токова је регистровано на територији Србије. Бујичне поплаве се према својим карактеристикам знатно разликују од поплава великх, алувијалних водотока. Њихова појава је нагла, после киша великог интензитета и углавном су кратког трајања, али са врло великм разорним дејством и катастрофалним штетама, а често пута и са људским жртвама. Њиховим дејством настају штете у урбаним зонама, на пољопривредним површинама и велика разарања на индустријским и енергетским објектима и на саобраћајницама (путевима и железницама). Путна мрежа Србија, поготову у брдско планинском региону, знатно је угрожена од бујичних поплава јер густа мрежа бујичних токова има велики број укрштања са путевима. Потврда овага је чињеница да на путевима I и II реда у сливу Колубаре дужине 1156 km регистрована су 523 укрштања са бујичним токовима и ту су потенцијални рузици од бујичних поплава. У овом раду се даје приказ kарактеристика бујичних токова и бујичних поплава и ризик од бујичних поплава, као и могућности одбране од њих у Србији.Уредници: Горан Младеновић, Драженко Глави
Примјена АПХ методологије и ГИС-а у геоеколошким истраживањима
No full textТрендови у геоеколошким истраживањима илуструју важне односе између просторних образаца и еколошких процеса и укључују примјену квантитативних метода које повезују просторне обрасце и еколошке процесе на широким просторним и временским скалама. Посљедњих година обраћа се већа пажња на просторну динамику, те наглашава потреба за развојем и коришћењем нових квантитативних метода које могу да анализирају узорке, утврде значај просторно експлицитних процеса на предјел и развију поуздане моделе намјене предјела, у првом реду водећи рачуна о одрживом коришћењу истог. Ипак, изналажење најподесније и најобјективније методологије у погледу геоеколошке евалуације простора (нарочито евалуације физичкогеографских компоненти), сложен је и деликатан задатак. Не тежи се само проналажењу елемената од којих је неки систем састављен, већ, прије свега, проналажењу релација између тих елемената. Развојем ГИС-а и информатичких технологија у геоеколошким истраживањима све више се користе методи мултикритеријумске анализе, од којих нарочиту примјену у новије вријеме доживљава АХП метод. У раду аутори ће сагледати могућности примјене АХП методологије у геоеколошким истраживањима, посебно у интеграцији са географским информационим системом, на примјерима евалуације природних потенцијала простора.Уредник: Душко Јоји
Mogućnosti primene LiDAR tehnologije za potrebe monitoringa šuma i šumskog zemljišta na području Republike Srbije
Get PDFŠume predstavljaju jedаn od najvećih prirodnih resursa svake države. Njihove uloge i funkcije su raznolike, a značaj za očuvanje životne sredine neprocenjiv. Šumski ekositemi važan su deo ukupnog biodiverziteta, činioci su stabilnosti klimatskih elemenata, prirodni su filteri vazduha, imaju značajnu hidrološku ulogu, umanjuju intezitet erozije, preventivno utiču na pojavu klizišta, osnova su razvoja brojih privrednih grana sa posebnim akcentom na turizam, a takođe imaju izražen naučni i edukativni karakter. Pod uticajem čovekovih aktivnosti pritisak na šumska područja izuzetno je pojačan. U cilju sprečavanja dalje degradacije i uspostavljanja održivog načina korišćenja šumskog zemljišta, između ostalog, neophodna je adekvatna i pravovremena informaciona osnova. Radi dobijanja podataka visoke tačnosti, u veliкom broju ekološki razvijenih zemalja koristi se LiDAR tehnologija (Laser Imaging Detection And Ranging). Tehnologija pruža visinske podatke o topografiji terena i na osnovu tih podataka izrađuju se digitalni modeli terena (DMT) visoke preciznosti. Na osnovu LiDAR podataka i DTM-a mogu se vršiti različite analize praćenja stanja šumskog pokrivača, zoniranje koriščenja prostora, kreiranje simulacija kretanja mogućih požara, procene zahvaćenosti, ugroženosti i verovatnoće pojavljivanja istih, procene nastale štete i slično. Bitno je napomenuti da ova merenja pružaju važne informacije svim korisnicima prostora kojima je topografija bitan ulazni podatak – organi uprave, službe za zaštitu i spašavanje, privatni sektor i dr.Urednici: Dejan Filipović, Velimir Šećerov, Slavoljub Dragićević, Zoran Radosavljevi
Extreme climate events and erosion control in headwater catchments of Serbia
No full textFloods are the most frequent natural catastrophic events worldwide (Berz et al. 2001; De Moel et al. 2009; Bissolli et al. 2011). In Serbia, the risk of torrential floods is the most common natural hazard, and a permanent threat of ecosystems, local and national economy, and social life (Kostadinov 1996; Dragićević et al. 2011). The average annual economic loss due to natural hazards over the world has been estimated at 40 billion EUR (MRG 2003), and, particularly, flash floods caused several serious loss of life and economic damage
Evaluation of the tourist potential and natural attractivity of the Lukovska Spa
No full textThere are, in Serbia, 240 geo-thermal areas, of which 60 host commercial spas. Most are found in the southern edge of the Pannonian Basin in the west and south-east of the country. Of these, the highest and one of the more potentially important spas is the Lukovska Spa, the subject of this paper. The study uses spatial modelling based on indices of attractiveness of geographical and touristic attributes to determine the attractiveness of Lukovska as a spa destination, and to indicate ways in which it might be managed
Continuing education of hotel employees and their shared vision of the organization
Get PDFA learning organization (continuing education of the employees) is a concept that is becoming an increasingly widespread philosophy in all adaptable companies, from the largest transnational to the smallest ones. Employees at all levels of the hotel organisation, individually and collectively, mainly continuously, increase their capacities through learning so that their engagement results in the accomplishment of the very tasks they are responsible for. The work aims to point out that learning hotel organisations, especially in crisis conditions, progress in changes, that is in adaptability and flexibility. The changes are to be undergone with the total capacity and with clear goals and plans. Certainly, even the well-measured changes carry risks and increased opportunities at the increasingly turbulent tourist market with constant tumultuous changes. The insufficient speed of adjustment, let alone stagnation, leads to the failure of business activities. Therefore, in the permanent learning hotel organisation, employees constantly find information sources and learn from the experiences of other participants in the tourist market, and, above all, discuss the needs of clients and customers. For this reason, the employees' learning is facilitated in all possible ways and rewarded for it is a great satisfaction for each individual if their work is valued. In such an organization, experiments, initiatives and innovations are encouraged, and each individual's participation is stimulated and encouraged in the hotel company. Achievements as well as errors are analysed and disclosed publicly since the sense of caring about each individual is developed and participated in the learning organization. This is because the contemporary shared vision of the learning organisation should be built on the vision of individual members of the hotel company