Lazar Lazic

Influence of Hail Suppression on the Hail Trend in Serbia

The influence of hail suppression by silver iodide seeding on the trend in the number of hail days (hail trend) in the Republic of Serbia was studied in three cases: (1) in Vojvodina region, Northern Province of Serbia, in two periods, from 1967 to 2002 when there was no hail suppression, and from 2003 to 2009 when hail suppression was extended to the entire territory; (2) in Serbia proper (Serbia without the Provinces), in two periods, from 1967 to 1984 when hail suppression was spreading, and from 1985 to 2009 when hail suppression occurred over the entire territory; and (3) in the same period from 1967 to 2002 on the two adjacent territories of Vojvodina and Serbia without the Provinces, where no hail suppression occurred in the first and hail suppression did occur in the second. The hail trend in Serbia was calculated on the basis of all observed data from all synoptic and climatological stations for the period 1967 to 2009. The results associate hail suppression with the stagnation of the hail trend rather than its decrease, and show that hail suppression did not have statistically unique influence on the hail trend.

The principles of sustainable development of tourism in the special nature reserve »Gornje Podunavlje« and their impact on the local communities

The development of tourism in protected areas is a particular challenge for the tourism business and the activity of nature conservation. The leading criteria for sustainable tourism in protected areas emphasize the importance of the adoption of certain principles of care, long-term planning and management that integrates nature protection and tourism. In this respect, the paper analyzes their importance in the case of Special Nature Reserve »Gornje Podunavlje« in Vojvodina. After acquiring the status of a special nature reserve, talk about the importance of this area to the tourism of Sombor and Apatin, where it is located, has increased. This trend follows the design of educational and tourist tracks, starting and running events as well as starting tourism businesses in rural households. There could be multiple benefits of this for the local communities.

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.

Determination of wind energy potential and its implementation concept for the electricity market in the Vojvodina region (north Serbia): An overview

Renewable energy sources play an important role in the future not only for the European countries, but for many countries worldwide. Most cost-effective and reliable large wind energy conversion systems are becoming the main focus of wind energy research and technology development, all in order to make wind energy competitive with other more traditional sources of electrical energy like coal, gas and nuclear generation. Serbia, along with neighbouring countries, has a high potential for developing energy production from renewable energy sources. Wind energy in Serbia, despite its great potential, is only partly studied and insufficiently used. This study aims to provide summary of wind energy potentials in the region of Vojvodina, which is an important economic region in northern Serbia. Its existing electrical energy status is thoroughly investigated according to the recent developments of wind energy production on global, regional and local scale. The main purpose of this study is the implementation of energy efficiency concept with purpose of satisfying the needs of Serbian electricity market.

Water regime and the direction of drainage of phreatic aquifer in the Backa loess plateau

Introduction The distribution of the phreatic aquifer and main characteristics of its regime are related to a number of very complex and interdependent phenomena and processes whose character has been defined by numerous factors among which the most important would be hydrological, pedological and geomorphological conditions, and especially the way, type and quantity of input, as well as of the output of water. The fluctuations of the water-table of the primary aquifer is, above all, a result of unsteady input and output of water, which is directly dependent of the uneven distribution of precipitation and the dominant temperatures of air and soil, i.e. the quantity of evaporation. Apart from the vertical component of the flow, and because of the relief conditions, there is also a horizontal movement of the phreatic aquifer from the high water-tables of the absolute height of the phreatic water-table to the low levels. The basic aim of this paper has established major characteristics of the water regime and the direction of the output of the phreatic aquifer of the Bačka loess plateau, as well as putting them into cause-result relation with the factors that characterise them.