Soil erosion caused by natural or anthropogenic factors represents a widespread problem with a range of negative environmental consequences. Various measures and works are being carried out to mitigate and prevent the direct and indirect effects of erosion. These actions often cannot be implemented in a whole region prone to erosion due to limited financial or human resources. Therefore, identifying the area that requires particular attention for conservation is necessary. The objective of this paper was to determine the most vulnerable areas (sub-watersheds) to soil erosion in the Topčiderska River Watershed, located in northern Serbia, using available data: land use, soil characteristics, and mean watershed slope. Using such multi-criteria decision analysis methods as analytic hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS), the most vulnerable sub-watersheds were determined for three different scenarios. The results show a strong correlation between the ranking based on AHP method and TOPSIS method. It is observed that the most vulnerable sub-watersheds are characterized by the significant presence of arable land and very steep slope and thus have priority for conservation.

Climate change has a direct impact on flash floods, and indirectly on the environment, society, and economy, due to the rapid development and difficulty of predicting this hydrological phenomenon. The main objective of this study is to assess the potential flash flood hazard areas in the Likodra watershed (218.62 km²), one of the most vulnerable parts to flash floods in Serbia, using the flash flood potential index (FFPI) and analytic hierarchy process (AHP) method. Recurring events from 1995 to this day and the devastating impact on settlements of the analyzed area show that this territory is extremely vulnerable. The data used include hydrological statistics (maximum daily rainfall) and spatial data on watershed geographical characteristics (slope, soils, land use, vegetation, drainage density) obtained or derived from various sources (maps, satellite images, digital databases) which were integrated into the GIS environment. The results indicate a severe flash flood hazard level, with high flash flood susceptibility classes occupying 76.20%, 87.78%, and 91.73% of the area, depending on the considered criteria and weights assigned to them.

Projects for the regulation of torrent basins carry various unforeseen adverse effects that may result in breached deadlines, increased costs, a reduction of quality etc. The paper presents the basic characteristics and most frequent risks associated with erosion control. Furthermore, it provides an overview of risk management through its basic stages - starting from risk identification and risk analysis to risk responses, including the methods used for risk analysis. As a part of quantitative methods for risk analysis, the Monte Carlo method is presented as the one most frequently used in simulations. The Monte Carlo method is a stochastic simulation method consisting of the following stages: the identification of criterion and relevant variables, the allocation of probability for relevant variables, the determination of correlation coefficient among relevant variables, simulation execution and result analysis. This method was applied in the analysis of the total cost of the project for the basin regulation of the Dumaca River in order to determine the funding that would be used as a backup in case of unforeseen events with a negative impact. The project for the regulation of the Dumaca River includes basin regulation in the form of complex flow profile and the lining of zones where necessary in terms of stability. The total cost is presented as a sum of costs of all works (preliminary works, earthworks, masonry works, concrete works and finishing works). The Monte Carlo simulation for cost analysis is carried out using the Oracle Crystal Ball software with its basic steps described in the paper. A sum of funding needed as a financial backup in case of unforeseen events with negative effects is obtained as the simulated total cost of the project.

In the spacious inundation area on the left bank of the lower course of the Sava River in Serbia, there is an abandoned meander Special Nature Reserve, “Obedska bara”, which represents a very important floodplain in this part of Europe. This area is characterized by an exceptional wealth of biodiversity with a significant presence of rare and endangered species of national and international importance. Hydrological conditions in the mentioned area were analyzed from the aspect of surface water movement in nature and conditions altered by human factors (after the construction of the road network, canals, etc.). The movement of surface water, i.e., the filling and emptying of the investigated area, parallel to the water level of the Sava River, is shown using a digital terrain model. Our simulation of the change in surface water level within the studied area included the display of underwater areas, both with the formation of a flood wave (i.e., increasing water level of the Sava) and with the outflow of water from the pond when the water level in the Sava was reduced in both scenarios (natural and conditions altered by human factors). GIS and terrain digitalization were used for geospatial and hydrological analyses and, based on this, maps that display endangered areas could be made. The obtained results show that the largest human impact was recorded at the water level of the Sava River 74 m above sea level. The aforementioned water regime changes were shown to negatively affect dominant vegetation, such as pedunculate oak and ash.

The main shortcomings in the implementation of the project for the regulation of torrent basins are the lack of application of the concept of planning and management. Planning, i.e. making plans, determines the need for resources (labor, materials, mechanization), duration of works and dynamics of works, which aims to economically build facilities in the shortest possible time and with minimal capacity (resources). To support the planning process, various programs can be used, which enable monitoring of the project implementation through its life cycle, i.e. initial ideas until its completion. The paper presents a comparative analysis of three computer programs, namely Primavera P6, Microsoft Project and GanttProject for planning the execution of works on the rehabilitation of the Kamenica dam.