Stevan Savic

Modelling of the Annual Mean Urban Heat Island Pattern for Planning of Representative Urban Climate Station Network

The spatial distribution of the annual mean urban heat island (UHI) intensity pattern was analysed for the medium-sized city Novi Sad, Serbia, located on the low and flat Great Hungarian Plain. The UHI pattern was determined by an empirical modelling method developed by (Balazs et al. 2009). This method was based on datasets from urban areas of Szeged and Debrecen (Hungary). The urban study area in Novi Sad (60 km2) was established as a grid network of 240 cells (0.5 km ×0.5 km). A Landsat satellite image (from June 2006) was used in order to evaluate normalized difference vegetation index and built-up ratio by cells. The pattern of the obtained UHI intensity values show concentric-like shapes when drawn as isotherms, mostly increase from the suburbs towards the inner urban areas. Results of this thermal pattern and determination of one of the local climate classification systems were used for recommending 10 locations for representative stations of an urban climate network in Novi Sad.

Variability of seasonal and annual precipitation in Slovenia and its correlation with large-scale atmospheric circulation

Abstract This paper examines temporal and spatial variability and trends of annual and seasonal precipitation in Slovenia and their relationship with three atmospheric circulation patterns represented by their indices: North Atlantic Oscillation index (NAOi), Mediterranean Oscillation index (MOi) andWestern Mediterranean Oscillation index (WeMOi). Data from 45 precipitation stations were used for the period 1963–2012.Mean annual precipitation varies from 736 mm in eastern Slovenia to 2,518 mm in northwestern Slovenia. A significant annual precipitation decrease (from −3% to −6% per decade) is observed in western Slovenia. Significant negative trends are observed in southwestern Slovenia in summer (from −4% to −10% per decade) and near the Adriatic coast in spring (from −6% to −10% per decade). Non-significant negative and positive trends are observed in winter and autumn, respectively. Results indicate significant correlations between winter precipitation and MOi (from −0.3 to −0.7), NAOi (from −0.3 to −0.6) andWeMOi (from 0.3 to 0.6). Significant We-MOi influence is observed in spring and autumn, while NAOi and MOi influence has not been detected. Annual precipitation and WeMOi are significantly correlated in central and eastern Slovenia, while significant NAOi and MOi influence is observed in western Slovenia (with the larger area covered by MOi influence).

Classification Methods for Inland Excess Water Modeling

Abstract Inland excess water floodings are a common problem in the Carpathian Basin. Nearly every year large areas are covered by water due to lack of natural runoff of superfluous water. To study the development of this phenomenon it is necessary to determine where these inundations are occurring. This research evaluates different methods to classify inland excess water occurrences on a study area covering south-east Hungary and northern Serbia. The region is susceptible to this type of flooding due to its geographical circumstances. Three separate methods are used to determine their applicability to the problem. The methods use the same input data set but differ in approach and complexity. The input data set consists of a mosaic of RapidEye medium resolution satellite images. The results of the classifications show that all three methods can be applied to the problem and provide high quality satellite based inland excess water maps over a large area.

Temperature-related Mortality in Belgrade in the Period 1888–2008

The paper uses air temperature and crude death rate data from Belgrade in the period from 1888 to 2008, in order to show expected correlation. Basic statistical analysis demonstrates statistically significant correlation values between these parameters. The starting assumption was that people in earlier times were more sensitive to extreme cold temperatures, particularly in the winter season. Statistical results confirm previous mentioned assumptionparticularly in the period before the First World War.Further analysis showed that in the last twenty years, air temperatures and death rates have opposite correlation outcomes. Statistical analysis points out that, in the last twenty years, death rates are increasing more rapidly in the summer season, due to increasing frequencies of extreme air temperature events.

Limnological characteristics, water regime and water quality problems of Borkovac reservoir (Vojvodina, Serbia)

In this study we present interdisciplinary investigations of the Borkovac reservoir (Vojvodina, Serbia). The limnological characteristics of the reservoir were analysed in the scope of its sustainable use for irrigation, fishing and tourism. This multipurpose water accumulation has been established in 1975 as a part of regional hydrological system of the Fruska Gora mountain region. The main environmental problems recognized in this study were: water regime, intensive sedimentation in the reservoir, enhanced water eutrophycation and toxic cyanobacterial blooms. Observed environmental problems and proposed solutions in the case of the Borkovac accumulation including construction of the sediment precipitator at the Borkovac stream junction to lake, sediment removal, artificial water mixing and oxygenation, phosphorous inactivitation, different kinds of biomanipulations and biomass removal and introduction of ecoremedation methods could also be applied to other artificial water bodies of the Fruska Gora slopes.

Modelled spatiotemporal variability of outdoor thermal comfort in local climate zones of the city of Brno, Czech Republic

This study uses the MUKLIMO_3 urban climate model (in German, Mikroskaliges Urbanes KLImaMOdell in 3-Dimensionen) and measurements from an urban climate network in order to simulate, validate and analyse the spatiotemporal pattern of human thermal comfort outdoors in the city of Brno (Czech Republic) during a heat-wave period. HUMIDEX, a heat index designed to quantify human heat exposure, was employed to assess thermal comfort, employing air temperature and relative humidity data. The city was divided into local climate zones (LCZs) in order to access differences in intra-urban thermal comfort. Validation of the model results, based on the measurement dates within the urban monitoring network, confirmed that the MUKLIMO_3 micro-scale model had the capacity to simulate the main spatiotemporal patterns of thermal comfort in an urban area and its vicinity. The results suggested that statistically significant differences in outdoor thermal comfort exist in the majority of cases between different LCZs. The most built-up LCZ types (LCZs 2, 3, 5, 8 and 10) were disclosed as the most uncomfortable areas of the city. Hence, conditions of great discomfort (HUMIDEX >40) were recorded in these areas, mainly in the afternoon hours (from 13.00 to 18.00 CEST), while some thermal discomfort continued overnight. In contrast, HUMIDEX values in sparsely built-up LCZ 9 and non-urban LCZs were substantially lower and indicated better thermal conditions for the urban population. Interestingly, the model captured a local increase of HUMIDEX values arising out of air humidity in LCZs with the presence of more vegetation (LCZs A and B) and in the vicinity of larger bodies of water (LCZ G).

Statistical Analysis of Water Quality Parameters in Seven Major Serbian Rivers during 2004‒2013 Period

Rivers on territory of the Republic of Serbia can be separated to three sea drainage basins: Black, Adriatic and Aegean. Majority of rivers belong to the Black Sea drainage basin. The Danube is the most important river in Serbia and one of the most important rivers of Europe. All rivers investigated in this paper represent direct or indirect tributaries of the Danube River and as that, they are belonging to the Black Sea drainage basin. In this study, the water quality status and the spatial and temporal trends of seven major rivers in Serbia were assessed through the application of ten parameters of Water Quality Index. Ten year (2004–2013) public database of environmental data was used. Into considerations were taken differences between every river individually and difference between sample positions on every single river. Based on the chemical parameters of water quality, it can be seen that the biggest rivers in Serbia show different values of WQ parameters. The highest WQ value is measured on the Drina River, while the lowest value is measured on the Južna Morava and the Tisza River. Analyses of parameters per period of year show that there is a statistically significant difference between values during warm and cold periods.

Heat wave risk assessment and mapping in urban areas: case study for a midsized Central European city, Novi Sad (Serbia)

Risk assessment and mapping methodologies for heat waves as frequently occurring hazards in central and southeastern Europe were applied in this study, and the impact of heat waves on the mortality of urban populations was determined as part of the assessment. The methodology for conducting the heat wave risk assessment is based on European Commission’s Guidelines for Risk Assessment and Mapping. The Novi Sad (Serbia) urban area was studied during summer 2015, which was one of the hottest summers in the last few decades. In situ air temperature measurements from urban stations and mortality of urban populations were used. Nocturnal urban heat island (UHI) intensity values between the various built-up zones and natural surrounding areas were used for the hazard level calculation. Temperature data from 9 p.m. to 5 a.m. were used because during the night, the UHI intensity reached its maximum values. The average daily number of deaths by LCZs was used to define the impact level of the vulnerability index. Calculations for both hazard levels were completed during two intensive heat waves (in July and August 2015) when it was expected that there may be a high level of risk. The results and maps show that the urban area is complex, and the heat wave risk on the population is not uniform. The most densely built-up areas (LCZs 2, 5 and 6) have very high or high risk values that are influenced by a higher rate of mortality. The obtained results and maps can be used by local authorities to prevent and mitigate climate-related hazards, for medical institutions as well as urban planners and for ancillary local, regional or national services. According to these results, the local authorities could define hot spots where they can place medical and rescue teams and install points with water supplies, etc.

Analysis of the climate change in Slovenia: Fluctuations of meteorological parameters for the period 1961-2011 - part I

This paper represents an analysis of the time series of selected meteorological parameters: mean, maximum and minimum air temperatures, sums of effective air temperature values with the temperature thresholds 5oC and 10oC, average precipitation quantities, number of days with frost, potential evapotranspiration and water balance. Study included data from 10 meteorological stations located on the territory of the Republic of Slovenia for the period 1961-2011. Analyzes were performed on a seasonal and annual basis. The obtained results showed a statistically significant positive trends of temperature parameters and potential evapotranspiration, while average precipitation quantities and water balance had a negative trend on the seasonal and annual basis. Positive trend of number of days with frost is present on most stations. In the second part of this paper, the obtained results were associated with the phenological data (data about the development of plants) in order to determine the intensity of correlation between them.

Main characteristics of water regime of the phreatic aquifer in Subotica municipality: Vojvodina, Serbia

Introduction Formation and distribution of the phreatic (unconfined, free, first, shallow) aquifer, groundwater layer the closest to topographic surface, primarily depends on the ruling hydrogeological conditions and relations that are perceived in the presence of rocks of intergranular porosity with favourable water collecting abilities within the top (covering) geological layer and impermeable rocks in the bottom geological layer of a certain geological complex. Main characteristics of the phreatic aquifer water regime result from the series of complex and interdependent phenomena and processes whose character is defined by numerous natural and anthropogenic factors. Among the natural factors, besides above-mentioned hydrogeological conditions, it is necessary to mention pedological, geomorphologic, fitogeographical and especially climate and hydrological circumstances. However, anthropogenic factor significantly modifies the natural regime of the phreatic aquifer in the areas with appropriate hydrotechnical works conducted or intensive irrigation/drainage of cultivated land (Pavić, 2006; Pavić et al., 2006; Pennington, Cech, 2010). Abstract