Nada Dragović

Erosion and sedimentation problems in Serbia

Erosion processes and sediment yield over Serbian territory are reviewed, as well as the distribution of sediment load in the hydrological network in Serbia. The overview of erosion problems consists of an analysis of the main erosion factors over the Serbian territory, a review of field investigations of soil loss and a description of the erosion control measures implemented in the region. The review of sedimentation problems includes a presentation of the sediment budget of the hydrographic network of Serbia, an analysis of bed load transport in the main Serbian rivers and consideration of issues related to the reservoir siltation.

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.

Non-wood forest products based enterprises’ cooperation and business networking forms in central Serbia

Collaboration between enterprises includes all activities, which are undertaken in order to achieve common goals and interests. Business networking involves the establishment of various forms of associations and business communities, with or without the creation of new economic entities. The aim of the paper was to study the forms of cooperation between non-wood forest products based small and medium enterprises, as well as to determine the attitudes of their representatives towards cooperation and business networking with other enterprises in Central Serbia. Research included 91 non-wood forest product based small and medium enterprises and 19 representatives of leading enterprises, which were selected based on specifically defined criteria. Both the methods of analysis and synthesis and comparative and statistical methods were applied in the paper. The results indicate that almost all analyzed enterprises cooperate with other enterprises. The most common form of cooperation is present “during selling” and “during purchase”. The majority of leading enterprises’ representatives are members of some of the existing associations of entrepreneurs. Based on the analysis, it was found that there is a need for development of cooperation between the analyzed enterprises. In accordance with that, proposals for the improvement of business networking were given. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Istraživanja klimatskih promena i njihovog uticaja na životnu sredinu - pracenje uticaja, adaptacija i ublažavanje”, podprojekat 43007/16-III: Socio-ekonomski razvoj, ublažavanje i adaptacija na klimatske promene i br. 37008-TR: Održivo gazdovanje ukupnim potencijalima suma u Republici Srbiji

Labour engagement optimization in planning the execution of river regulation works on the Jelašnička river

A project is a task comprising a set of interrelated activities requiring time and resources for their execution. It is often the case that during the construction of longitudinal and cross section structures for the regulation of a torrential catchment the required resources (labour, materials, mechanization, and finances) are often limited and because of that we face the problem of their efficient use. This paper deals with the problem of planning the execution of river regulation works on the Jelasnicka River with the aim to minimize the time extension due to limited resources. In the planning phase of project realization labour force is the limited resource. Heuristic techniques, i.e. the Gray-Kidd algorithm with the use of MS Project software were applied in the distribution of resources for the purposes of optimal labour engagement. This method uses the data acquired by the CPM method of network planning as input elements. Through more iterations, by moving noncritical and then critical project activities, the minimal extension of project duration was achieved by engaging more labour force. Therefore, the proposed heuristic and CPM method performed well in resolving the resource-constrained project scheduling problem. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Istraživanje klimatskih promena na životnu sredinu: pracenje uticaja, adaptacija i ublažavanje , podprojekat br. 16: Socio-ekonomski razvoj, ublažavanje i adaptacija na klimatske promene]