Can the desiccation of forests in Tara National Park (Serbia) be attributed to the effects of a drought period?

Forest ecosystems within national parks are threatened by various biotic and abiotic factors.To deter-mine the causes of the desiccation and death of trees in mixed coniferous and deciduous forests of Tara National Park(TNP),Serbia,we monitored defoliation and mortality of individual trees in permanent experimental plots.Data on the desiccation of a large number of trees were gathered by determining the total volume of dry trees and areas of forests under drying stress.The two sets of data were combined to determine the impact of climatic events,primarily drought periods,on the desiccation of forests.Combining data from the International Co-operative Program on Assessment and Monitoring of Air Pollution Effects on Forests(ICP Forests)with TNP data helped relate forest desiccation to climate events.Key climate signals were identified by monitoring tree defoliation changes in two permanent experimental plots,and then assessed for their influence on tree desicca-tion in the entire national park.The standardized precipita-tion evapotranspiration index(SPEI)was used for a more detailed analysis of the drought period.Despite the lack of climate data for a certain period,the SPEI index revealed a link between climate variables and the defoliation and desic-cation of forests.Furthermore,the desiccation of trees was preceded by a long drought period.Although mixed conifer-ous-deciduous forests are often considered less vulnerable to natural influences,this study suggests that forest ecosystems can become vulnerable regardless of tree species composi-tion due to multi-year droughts.These findings contribute to a better understanding of important clues for predicting pos-sible future desiccation of forests.Continuous monitoring of the state of forests and of more permanent experimental plots in national parks could provide better quality data and timely responses to stressful situations.

Strategy for Protection of Cultural Heritage Exposed to the Natural and Man-Made Activity Disasters in Serbia

Natural disasters and the adverse human activities are the key events in the history of mankind that form our history and shape our collective memory to this day.People on the planet Earth are not obsessed only with natural hazards,caused by earthquakes,floods and volcanic eruptions,and troubles unlikely come solely from the action of nature.Disasters threatening the human race can be caused also by people themselves.Both types of disasters cause vast human suffering,at the same time destroying cultural heritage as well,that has the function of determining the identity of social communities.These sufferings should be added to those that can be determined only by in-depth analyses which are derived from the synergy of natural forces and mistaken choices made by the humans,when it comes to their habitat.The proposed strategic plan for protection of built heritage in emergency situations may become the powerful catalyst for the process of revitalization by which the social tissue of community is maintained and restored,creating the symbol of resistance by which it endures each and every natural element and evil men behaviour.

Hepatitis C virus genotypes in Serbia and Montenegro: The prevalence and clinical signifi cance

AIM： To investigate the prevalence of hepatitis C virus （HCV） genotypes in Serbia and Montenegro and their influence on some clinical characteristics in patients with chronic HCV infection. METHODS： A total of 164 patients was investigated. Complete history, route of infection, assessment of alcohol consumption, an abdominal ultrasound, standard biochemical tests and liver biopsy were done. Gene sequencing of 5＇ NTR type-specific PCR or commercial kits was performed for HCV genotyping and subtyping. The SPSS for Windows （version 10.0） was used for univariate regression analysis with further multivariate analysis. RESULTS： The genotypes 1, 2, 3, 4, 1b3a and 1b4 were present in 57.9%, 3.7%, 23.2%, 6.7%, 6.7% and 1.8% of the patients, respectively. The genotype 1 （mainly the subtype 1b） was found to be independent of age in subjects older than 40 years, high viral load, more severe necro-inflammatory activity, advanced stage of fibrosis, and absence of intravenous drug abuse. The genotype 3a was associated with intravenous drug abuse and the age below 40. Multivariate analysis demonstrated age over 40 and intravenous drug abuse as the positive predictive factors for the genotypes lb and 3a, respectively.CONCLUSION： In Serbia and Montenegro, the genotypes 1b and 3a predominate in patients with chronic HCV infection. The subtype lb is characteristic of older patients, while the genotype 3a is common in drug abusers. Association of the subtype lb with advanced liver disease, higher viral load and histological activity suggests earlier infection with this genotype and eventually its increased pathogenicity.

Sustainable tourism development in mountain areas in Sumadija and Western Serbia

Sustainable tourism,as an integral part of sustainable development,emerged as a logical outcome of preventing the uncontrolled and excessive use of tourism resources and attractions.This study analyzes whether mountain tourism development in Serbia can be sustainable and feasible in the long term.Given the heterogeneity of mountains in Serbia in terms of tourism development,the subject of this research is the achieved level of sustainable tourism development in mountains in the most developed and most visited region in Serbia-sumadija and Western Serbia:Zlatibor,Kopaonik,Tara,Zlatar,Mokra Gora and Go?.The sustainable tourism development level was analyzed by using five groups of the EU’s comparative indicators:economic,social,cultural,environmental and tourist satisfaction indicators.The results showed that the development of tourism in the examined mountains is not fully aligned with sustainable development.The tourist satisfaction indicator has the most acceptable values,which is a good basis for further harmonization of tourism development on the principles of sustainability.Economic indicators,especially the ratio of overnight stays and accommodation capacities,show the most unacceptable values,which indicate the need for implementing changes in the process of tourism development in the coming period.The analysis of sustainable tourism in mountain areas in sumadija and the Western Serbia undoubtfully points out that it is necessary to significantly change the current tourism product portfolio,which implies harmonizing mountain tourism development with global trends.Certainly,a comparative analysis that looks at the degree of sustainability of mountain tourism in some countries of the Alpine region,such as Switzerland,Austria and Slovenia,contributes to this.The more intensive development of tourism throughout the year would significantly improve indicators of sustainable tourism in all analyzed mountain areas of Sumadija and Western Serbia.This would improve the value of economic indicators,which are marked as the most unsustainable.The development of tourism in the summer season,especially recreational and adventure tourism,would improve the social and cultural component of sustainable tourism.Environmental dimension of sustainable tourism would be enhanced by the development of ecotourism.By connecting spatially close mountains(Zlatibor,Zlatar,Tara and Mokra Gora)into a unique and integrated tourism destination,synergistic effects would be achieved resulting in international recognition and making the region of?umadija and Western Serbia competitive on the European market.

Validation of the Glaucoma Quality of Life-15 Questionnaire in Serbian language

AIM：To translate the Glaucoma Quality of Life-15（GQL-15）to Serbian language and asses its validity and reliability in the population of Serbian patients.METHODS：The study included 177 glaucoma patients.Clinical parameters（visual acuity,mean defect and square root of loss variance of visual field）and socio-demographic data were collected.Patients were stratified according to the Nelson’s glaucoma staging system as mild,moderate and advanced glaucoma.All patients filled out the GQL-15 and National Eye Institute Visual Function Questionnaire（NEI-VFQ 25）.The GQL-15 was translated following the internationally-accepted methodology,and its psychometric properties were assessed by using classical test theory and Rasch analysis.RESULTS：The mean total score for the GQL-15 was 20.68±7.31.The Cronbach’s alpha coefficient for the whole scale was 0.89（central and near vision,α=0.24;peripheral vision,α=0.85;glare and dark adaptation,α=0.83）.Factor analysis established 4 factors（70.3% of variance）：two corresponding to the original factors and two new factors specific for the Serbian population.The GQL-15 score correlated positively with almost all clinical parameters and NEI-VFQ 25 proving good criterion validity.Correlation of the GQL-15 total score on test-retest confirmed appropriate scale reproducibility（ρ=0.96,P〈0.001）.The GQL-15 discriminated well advanced from mild and moderate glaucoma.In Rasch analysis we obtained adequate item（0.95）reliability index.Almost all items had infit and outfit mean squares in the accepted range.CONCLUSION：Serbian version of the GQL-15 demonstrates adequate reliability and validity.This version of the GQL-15is a valid instrument for evaluation of quality of life among Serbian speaking patients with glaucoma and can be applied in daily clinical work.

Temple of Diana in Timacum Minus and Some Aspects of Cult of Diana in Territory of Serbia

Three votive monuments dedicated to the cult of Diana have been identified to date in the territory of Roman Municipium Timacum Minus. Two of them are related to erection and restoration of the temple of Diana. According to onomastic formulae of the dedicants’ names, the first monument may be dated into the period of Emperor Hadrian’s rule or immediately after it, and the other into the period of the reign of Marcus Aurelius or directly following it. The main methodological approach in this paper was researching Diana’s cult in general, and then also examining analogies to votive monuments from Timacum Minus in the territory of Serbia. Even though there have been only five such monuments identified to date, analogies show that it was already in 2nd century that the influence of Romanisation in the territory of Serbia was well under way, and that in worshipping Diana, her companions the nymphs, and Apollo-Diana-Silvanus, it was indeed Roman deities that were being worshipped and not interpretatio Romana of indigenous deities. Socio-economic position of the dedicants indicates that they belonged to middle or upper social strata （legatus legionis VII Claudiae piae fidelis, duumvir, pontifex, eques Romanus）.

Innovation in the Manufacturing Sector： The Case of Serbia

The paper presents the results of research on innovation activities of manufacturing firms in Serbia. In order to answer the question how innovation takes place in one transition country, key influencing factors were identify （i.e., firm＇s size, age, ownership, industry sector, personnel qualifications and experience）. Based on the analysis of a sample comprising 73 firms, the study tried to highlight certain innovation barriers, which may have a negative impact on the total efficiency of economic performance, and growth and development of manufacturing firms in Serbia. Comparing overall innovation activities of Serbian firms to the other transition countries, it can be concluded that majority of the fhnns had innovation performances below the level EU-27. This study draws out the potential contributions to existing literature of managing innovation in Serbia.

Serpentine Design on Forest Roads by the Internal Circular Curve Method： A Case Study in Serbia

The paper provides an overview of geometric solutions of marking all types of serpentine by the method of internal circular curve in designing forest roads directly in the field. The main objective of presenting this original method for marking all serpentine types in one place is to show similarities and differences in marking different types of serpentine, and identify opportunities for further research of this type. The method is based on the establishment of the minimum number of elements necessary to mark the serpentine on the forest roads and other budget elements and their design in the field. By using this method, construction errors or the number of attempts of serpentine marking are reduced, which increases the effects of design compared to the ones reached by the previous method of marking the serpentine on forest roads.

Management in Sustainable Tourism Development of Serbian Spas

Since Serbia disposes with significant natural potentials, it could have been among the most attractive countries in Europe only if the historical circumstances had been different. Existing natural resources and possibilities for their improvement demand planned strategy to make them efficient. Tourism, as a significant instrument of development, can and should take an active part in the strategy of sustainable development. Special attention in the paper is paid to the development of Vrnjacka Banja Spa as it is one of the main tourist destinations in Serbia. The strengths, weaknesses, opportunities, and threats of a business venture （SWOT） analysis offers the basic elements for defining the strategic direction and program priorities, measures and targets for improving the overall development of spas in Serbia. To identify the SWOT factors, we used materials from a number of studies on Serbian tourism, surveys on tourists in Vrnjcka Banja Spa and analysis of the market and competition. The SWOT analysis proves that the priority in development of spas in Serbia is attractiveness of the destination which involves the spa-health tourism with great potential in complementary forms of tourism, such as sport-recreational, cultural, transit and hunting tourism. It means that the future strategy should be based on improving and involving modern spa products. It means improving and maximizing marketing so as to make the tourist destination attractive. It further implies maximum investment in modern tourist products.

The Study of Supply and Demand of Organic Products in the European Union and Serbia

One of the phenomena that marked 20th century is rapid technology progress. This process did not avoid food production and processing. Thanks to rapid development of technology, there has been a development of conventional food production, as well as appearance of genetically modified food. As a consequence of this trend, as well as the concern among some part of human population for their health, we had the return to natural food production in the form of the development of organic food production. One of the characteristics of organic food market in the European Union is the constant growth of demand for this product group, and insufficient quantities of organic products available in this market. These information led to the conclusion that organic food represents an opportunity for less developed countries, i.e., that countries like Serbia can manufacture and sale these products on the market with the highest purchasing power in the world--the European Union market. In this paper, the characteristics of demand for organic foods in the European Union were presented, then it was explained in detail why are these products export chance of Serbia, as well as reasons why is the export of organic food from Serbia to the EU very low at the time being. At the end, some recommendations that could help Serbia to increase export of organic product to EU countries were proposed.

Internet Marketing Law Frameworks in Serbia

The term internet marketing in the business and organization of campaigns in Serbia is at the beginning of its development.This paper gives an overview of the current state of this branch of marketing with a special emphasis on IT law.Analyzing marketing communication and application in modern information systems,the paper gives answers about the impact of the same on internet marketing.On the other hand,considering the current state of the development of the information society in Serbia,as well as the legal aspects in which internet marketing is currently underway,will try to explain the current state of this branch of marketing in Serbia.

Trends in suicide by hanging, strangulation, and suffocation in Serbia, 1991-2020: A joinpoint regression and age-period-cohort analysis

BACKGROUND Hanging is one of the most commonly used methods for suicide in both sexes worldwide.In a number of countries,hanging mortality has increased over the last decades.Nevertheless,there is a scarcity of studies that have explored the patterns and trends for mortality of suicide by hanging on global,regional and national levels,as most evaluations are limited to certain populations.AIM To assess the trends of suicide mortality by hanging,strangulation,and suffocation in Serbia,from 1991 to 2020.METHODS This nationwide study,with epidemiological descriptive study design,was carried out based on official data.The age-standardized rates(ASRs,expressed per 100000 persons)were calculated by direct standardization,using the World Standard Population.Mortality trends from suicide by hanging were assessed using the joinpoint regression analysis:The average annual percent change(AAPC)with the corresponding 95%confidence interval(95%CI)was calculated.Age-period-cohort analysis was performed to address the possible underlying reasons for the observed suicide trends.RESULTS Over the 30-year period studied,there were 24340 deaths by hanging(17750 males and 6590 females)in Serbia.In 2020,the ASR of deaths by hanging was 4.5 per 100000 persons in both sexes together(7.6 in males vs 1.7 in females).The trends of suicide mortality by hanging decreased significantly between 1991 and 2020 in both males(AAPC=-1.7%per year;95%CI:-2.0 to-1.4)and females(AAPC=-3.5%per year;95%CI:-3.9 to-3.1).Mortality rates of suicide by hanging had a continuously decreasing tendency in both sexes together in all age groups:The only exception was among males in 40-49 age group,with an increasing trend of suicide by hanging from 1991 to 2011(by+0.3%per year).CONCLUSION The trends in suicide mortality by hanging have been decreasing in Serbia in the last three decades in both sexes,but this was more pronounced in women than in men.Despite the decreasing trends observed in mortality of suicide by hanging,further research is needed for better clarification of trends and help in suicide prevention in the future.

Sustainable development of lignite production on open cast mines in Serbia

Energy sector represents a key industrial branch for national, environmental and economic success. With its exclusive access to domestic deposits, lignite industry represents a guarantor of reliable raw materials, offering long-term supply security based on verified reserves. Currently operated coalmines in Serbia (Kolubara and Kostolac) have production around 36 million tons of lignite, and over 108 million m3 of overburden. Consequently, sustainability of lignite production requires cost reduction and environmental protection, as well as capacity increase. In order to rationalise, and increase efficiency of Serbian lignite mines, it is necessary to focus the activities on major issues shown within the triangle of energy policy objectives (security of supply, competi- tive prices and environmental protection). Production process optimisation singled out several special programs. Equipment revi- talization and modernization is necessary taking into account that majority of the currently operated machinery has a life up to 25 years. Production process automation would enable high level of technical operation in the field of open cast mines management. Lack of coal quality uniformity is the permanent problem resulting by great amounts of coal reserves to be used uneconomically. Planning and training at all levels and finally cooperative software for business procedures and work order management. The measures suggested are a key precondition for maintaining competitive position of lignite production on international level.

The Diagenesis of Plant Lipids during the Formation of the Krepoljin Coal Basin(Serbia)—Using Multivariate Statistical Analysis in the Saturated Biomarkers

The composition of the saturated hydrocarbon fraction of soluble organic matter （bitumen） from the Krepoljin brown coal basin （East Serbia） of Miocene age was investigated. The Krepoljin basin is especially interesting from a geochemical point of view. Namely, by the end of Tertiary Period, the basin was covered by powerful Mesozoic formations of great possibilities, the bedding became hermetically enclosed and protected from subsequent external influences. The nature of early diagenetic processes in the environment with abundant accumulation of organic substance is defined by the molecular content of bitumen through the connections of molecular structures to potential precursors in paleoplant phylla, as well as by the degree of their diagenetic transformations. The hierarchy of parameters based on molecules of saturated hydrocarbons was determined by applying the principal component analysis to the soluble organic matter. The most significant, most ＂loadings＂ values of component CI, are the plant types such as precursors or participants in early diagenetic transformations of steranes Cs27-algal precursor material, Cs28-moulds, Cs29-higher land and water plants; resinous from the group of higher plant gymnosperms （G）; also triterpanes a and β-amirindicotyledonous angiosperms （A） and bacterial and/or terrestrial plants population represented by hopanes/moretanes; as well as the parameters which describe the degree of diagenetic/maturation transformation of precursor biomass, and based on next reactions： （1） shifting of methyl group, influenced by the inorganic sediment constitutents, sterane-rearranged steranes, （2） isomerization in the ring system, ααα→βββ C29 sterane as well as （3） isomerization on chiral center of the side chain sequence R→S C29 sterane S/（S＋R）. Additionally, a pyrite-derived inhibitory effect on the rearrangment of C29 steranes must be taken into account, but not on triterpanes reaction. Non- appearance of statistically important correlations, before all with maturational depended parameters, and after all also with source indicators contributies to the affirmation of the newly-suggested parameter α-Phyllocladane/S27 as the real source biomarker of coal. Indicators derived from the distribution and abundance of n-alkanes and isoprenoid alkanes are of less significance in hierarchy of parameters.

Sedimentation History of Neogene Lacustrine Sediments of Sueoka Bela Stena Based on Geochemical Parameters(Valjevo-Mionica Basin,Serbia)

Sediments of the western part of the Valjevo-Mionica basin （Serbia） were examined both geochemically and mineralogically to explain, on the basis of their sedimentologicai characteristics, the causes of changes in their qualitative and quantitative composition. A total of 62 samples obtained from the drillhole at depths up to 400 m was investigated. Using correlation of the obtained data, six geochemical zones were defined, two of which being specially distinguished by their mineralogical, geochemical and sedimentological characteristics. The first one, upper zone A, consists of banded marlstones interbedded with clay and oil shales and is characterized by presence of analcite and searlesite. These minerals and very high contents of Na20 indicate sedimentation in alkaline conditions with increased salinity in arid climate. That provided pronounced water stratification, as well as higher bioproductivity in the basin and sedimentary organic matter preservation. Therefore, the zone A sediments are characterized by high organic matter contents of the type which provides good potential for production of liquid hydrocarbons. Another specific zone, zone F, contains sediments with very high MgO, K2O and Li concentrations. Their geochemical correlation, as well as almost complete absence of illite in this zone, indicates the presence of interstratified clay mineral type illite-saponite （lithium-bearing Mg-smectite）.

Macroscopically-Zoned Grandite from the Garnetite Skarn of Meka Presedla(Kopaonik Mountain,Serbia)

The macroscopically-zoned grandite from the garnetite skarn of Meka Presedla （Kopaonik Mountain, Serbia） was studied with optical microscopy, electron microprobe analysis （EMPA）, Fourier transform infra-red （FT-IR）, and Raman methods. The EMPA results indicate that the main core-rim compositional variations （Ca2.93-2.97Mn0.05-0.06Mg0.00-0.01AI1.14-L26 Fe0.72-0.83 Ti0.00-0.02Si2.97-3.02012） slightly differ along the zones, showing evidence for a quasi-cyclic alternation of the oscillatory zoning nature. Among this, considerable variation is observed only by the AI-Fe3＋ substitutions in the octahedral site. The EMPA also indicate that the grandite zones compositionally vary, mostly within ＋1 and ±2 mol% of the homogeneity level range, that is, Grs64±1Adra36±1SpS2 （A）, Grs62±1Adra38±1Sps2 （B）, Grs59±2Adr40±2Sps2 （C）, Grs58±2Adr41±2Sps2 （D）, and Grss±1Adr41±1Sps2 （E）. Therefore, the investigated garnet can be considered as relatively highly homogeneous. The majority of compositions lie within the narrow miscibility region of 0.58±2〈XGrs〈0.64±1, without gaps, and with only three outliers near the zone boundaries of approximately 0.38〈XGrs〈0.52. FT-IR and Raman bands are almost constant within the zones and adequate to the chemical compositions. All of the zones should be considered as anhydrous. From the results, formation temperatures between -600 and 720℃ and pressures 0f-2-3 kbars, are derived. Among five possible causes for the slightly optical anisotropy of grandite, three were reconsidered, and consequently rejected.

Crystal Structure and Chemical Composition of Ludwigite from Vranovac Ore Deposit (Boranja Mountain,Serbia)

The crystal structure of ludwigite from Vranovac ore deposit （Boranja Mt., Serbia） was refined using the X-ray powder diffraction （XRPD） Rietveld method in the space group Pbam to a final RB=7.45% and RF=5.26%. It has the unit cell dimensions of： a=9.2515（2） A; b=12.3109（2） A; c=3.03712 （7） A; and V=345.91（1） A3. The calculated distances and angles are mostly in good agreement with the Mg2＋-Fe2＋ substitutions across the M（1） and M（3） sites, as well as with the Fe3＋-AI3＋ replacement in the M（4） site. However, the mean observed M（2）-O distance is considerably shorter than prescribed, due to a slight increase of the Fe3＋ content in the M（2） site. Such replacement was compensated by slight increase of the Fe2＋ content in the M（4） site, resulting in the （Mg1.4sFe2＋o.46Fe3＋o.osMno.o2）2.o1 （Fe3＋o.94Fe2＋0.04Al0.02）1.00B1.00Os composition. The formation temperature was estimated to be about 500- 600C. The influences of the various chemical compositions to the crystallographic parameters, M-O distances, M（3） and M（4） sites shift, distortion parameters and estimated valences, were also studied and compared with other reference samples.

Land use optimization for sustainable development of mountain regions of western Serbia

This study analyses the possibilities for optimal land use structure in mountainous areas of rural Serbia, which is faced with problems such as unfavorable terrain characteristics and inadequate land use patterns causing economic underdevelopment and increasing population migration. In the case of a small privately owned farm in Western Serbia, optimal land use pattern is determined using the linear programming model. The objective function-cost-effectiveness or soil erosion reduction, as well as constraints, are formulated using the benefit-cost ratio(BCR) for a 15-year production period and soil losses data calculated using the Universal Soil Loss Equation(USLE). The best results are achieved using the scenario with the aim to minimize soil erosion, considering the BCR in the constraints. This scenario is proposed since it was registered that the benefit for landowners would increase by five times, while the losses of land would decline about 80%. The sensitivity analysis of investments is performed to check whether the price variation affects the cost-effectiveness of proposed land use. Results show that market changes(nine cases are considered) do not lead to significant changes in land use allocation. Proposed land use pattern improves the environmental condition, strengthens the rural economy and thus offers the greatest potential for sustainable development of mountainous rural areas.

Topographic and lithologic controls behind mountain depopulation in Zlatibor District(Western Serbia)

Mountain depopulation is a worldwide phenomenon observed in all continents. It has varied socio-economic reasons;among others, the low profitability of traditional agriculture, the better job possibilities and the higher level of services in urban settlements. However, it is often recognized that depopulation is related to natural factors such as elevation, slope or lithology. It is also observed that protected areas are frequently established in depopulated mountain regions. Their primary aim is the conservation of nature, but they may help tourism development as well. Tourism, in turn, may slow down or even reverse the process of depopulation. In this study, we investigate the impact of topographic and lithologic factors, namely of karst settings, on mountain demographic processes and the relationship of protected areas and tourism through the example of the northern part of Zlatibor District(Western Serbia). The study area is characterized by mountains and hills at elevations from 200 to 1600 m a.s.l. Our aim is to find GIS-based statistical relationships between topographic, lithologic factors and demographic characteristics. In this area, mountain depopulation started after WWII, and weproved that this process was strongly controlled by topographic factors. The higher and more dissected the area, the more significant is the decrease of the population and the more advanced is the ageing. As a result, population density contrasts are much more pronounced now than 70 years ago. After WWII, depopulation and ageing became gradually more serious on karstic terrains than on non-karst. However, by using compound topographic and lithologic types, we proved that it is not the effect of karst, but the effect of topography. The flow of population from hills and mountains to valleys and basins are closely related to the restructuring of the economic sectors. At present, for the study area, the development of tourism is unequivocally naturebased and connected to protected areas, namely to Tara National Park, Zlatibor Nature Park and ?argan–Mokra Gora Nature Park. In this paper, we also demonstrate how lithology influences tourism possibilities. The leading role of Zlatibor in tourism development is largely thanks to its favourable position on a main transit route.

Spatial prediction of landslide susceptibility in western Serbia using hybrid support vector regression(SVR)with GWO,BAT and COA algorithms

In this study,we developed multiple hybrid machine-learning models to address parameter optimization limitations and enhance the spatial prediction of landslide susceptibility models.We created a geographic information system database,and our analysis results were used to prepare a landslide inventory map containing 359 landslide events identified from Google Earth,aerial photographs,and other validated sources.A support vector regression(SVR)machine-learning model was used to divide the landslide inventory into training(70%)and testing(30%)datasets.The landslide susceptibility map was produced using 14 causative factors.We applied the established gray wolf optimization(GWO)algorithm,bat algorithm(BA),and cuckoo optimization algorithm(COA)to fine-tune the parameters of the SVR model to improve its predictive accuracy.The resultant hybrid models,SVR-GWO,SVR-BA,and SVR-COA,were validated in terms of the area under curve(AUC)and root mean square error(RMSE).The AUC values for the SVR-GWO(0.733),SVR-BA(0.724),and SVR-COA(0.738)models indicate their good prediction rates for landslide susceptibility modeling.SVR-COA had the greatest accuracy,with an RMSE of 0.21687,and SVR-BA had the least accuracy,with an RMSE of 0.23046.The three optimized hybrid models outperformed the SVR model(AUC=0.704,RMSE=0.26689),confirming the ability of metaheuristic algorithms to improve model performance.