Ratko Ristic

Land use change for flood protection: A prospective study for the restoration of the river Jelašnica watershed

Serbia’s hilly-mountainous regions are extremely vulnerable to flooding as a consequence of their natural characteristics and human impacts. Land mismanagement influences the development of erosion processes, and causes soil degradation that significantly reduces the land’s capacity to infiltrate and retain rainwater. Inappropriate land use as well as development activities replace permeable with impervious surfaces in the watershed. This leads to more rapid runoff generation and the more frequent appearance of torrential floods and bed-load deposits on downstream sections. Environmental degradation creates economicsocial problems within local societies which is often followed by depopulation. Restoring watersheds to their optimal hydrologic state would reduce flood discharge and by increasing groundwater recharge would increase both low-flow and average discharges in springs and streams. Best management practices could be developed through the application of specific combinations of biotechnical, technical and administrative measures, and by using the concept of ″natural reservoirs″. The design of such practices is explored through a case study of the watershed of the river Jelasnica, southeastern Serbia. Realization of these planned restoration works should help decrease the annual yields of erosive material by 44.1% and the specific annual transport of sediment through hydrographic network by 43.6%. Representative value of the coefficient of erosion will be reduced from Z=0.555 to Z=0.379. The value of maximal discharge Qmax-AMCIII (1%)=54.17 m3•s-1, before restoration, is decreased to Qmax-AMCIII (1%)=41.22 m3•s-1 after restoration, indicating the improvement of hydrological conditions, as a direct consequence of land use changes. Administrative measures are applied through ″Plans for announcement of erosive regions and protection from torrential floods in the territory of Leskovac municipality″.

Land Degradation at the Stara Planina Ski Resort

The environmental impacts of ski resorts in the Balkan region are great and can lead to landscape degradation and loss of land functionality. In this study, we present an example of the negative effects of human activities at the Stara Planina ski resort in southeastern Serbia. The objective of this study is detailed analysis of the characteristics of environmental impacts at the Stara Planina. The management of the ski area and ski slope development caused severe degradation of topsoil and native vegetation. The morphological characteristics of the area, lithological properties of the exposed material and climate conditions resulted in various geomorphic impacts, including rills, deep gullies, solifluctions and debris from rock weathering. Significant changes in land usage altered hydrological conditions, resulting in more frequent torrential floods in the downstream sections of the Zubska River and increased the sediment yield. Environmental impacts were analyzed in the immediate and wider zones of the ski resort in accordance with the specific topography and visual exposure. The restoration and erosion control measures have stopped degradation processes and helped to rehabilitate the appearance and functions of the landscape. The results show the importance of considering lithological (the type and characteristics of minerals present) and hydrological (precipitation, water storage capacity of soil, runoff) factors under the conditions of significant changes in land usage. The results of this investigation can contribute to the improvement of planning processes and the implementation of development projects in ski areas.

Floods in Serbia in 2010 – Case Study: The Kolubara and Pcinja River Basins

Riverine and torrential floods are the most significant natural hazards on the territory of Serbia. The potentially flooded area in Serbia with a 100-year return period is 15,198.07 km2 (17.2% of total area). Serbia is mostly threatened by the floods of small to medium-size torrential rivers mostly in late spring (from May to the end of June), a period characterised by intensive rainfalls of a few-hour duration. In the Pcinja River Basin, the town of Trgoviste was struck by a flood in May 2010. Two people were killed, almost 170 ha of land and 27 buildings were flooded (including 12 severely damaged), roads damaged or blocked, and 230 inhabitants evacuated. The flood in the Kolubara River Basin of late June 2010 affected 500 ha with 230 flooded households. Total damage was estimated at €370,000. In the watersheds studied, the 2010 floods were natural occurrences, but human action significantly aggravated the disasters. The messages to be learned help improve the system of prevention and the organisation of mitigation of flood damages, in order to reduce it to an acceptable level.

Restoration of eroded surfaces in Serbian ski-areas.

The environmental impacts in Serbian ski areas are very strong, leading to landscape degradation and functionality losses. Construction or improvement works cause serious destruction of topsoil and native vegetation. Some activities enhance erosion production and sediment yield: clear cuttings; trunk transport down the slope; road construction and large excavations. Also, lack of erosion control works in ski areas, especially between April and October, result in various forms of land degradation such as furrows, gullies, landslides, or debris from rock weathering. The consequences of mismanagement in ski areas are noticeable in downstream sections of river beds, causing floods and bed-load deposition. Planning and designing activities, with the application of technical and biotechnical erosion control structures, through the concept of restoration, are necessary measures in the protection of ski areas.

Groundwater Quality Degradation in Obrenovac Municipality, Serbia

Water has no definition. Any interpretation, explanation, its formula or description, does not actually represent anything of what it really is. Although much is written about it and we think to know all, yet, it remains a great mystery to us. The water is like religion. Everywhere around us, does not impose, used as needed, usually mechanically, we are unable to recognize the salvation role in it. When we have enough water and turn it into a “servant” (means of use), we relate to it with negligence, just like we do with the faith in times of welfare. Only the lack of water and the need for it create a sense of ontological connection to us. And then we devote ourselves to prayer. And the greater the need for it becomes, the more zealous the prayer is.

DEGRADATION OF LANDSCAPE IN SERBIAN SKI RESORTS-ASPECTS OF SCALE AND TRANSFER OF IMPACTS

The environmental impacts in Serbian ski resorts (Kopaonik, Zlatibor, Stara planina, Divcibare) are very strong, leading to degradation of unique mountain landscape, and functionality losses. Processes of urbanization, construction or improvement works, cause hard degradation of topsoil and native vegetation. The logging, large excavation activities, erosion, noise and water pollution constantly impact the habitats of all animal and plant species residing in small areas. The process leads to severe fragmentation of the remaining old-growth forests, endangering future subsistence. Consequences of mismanagement in ski areas are noticeable in downstream sections of river beds, causing floods and bed-load deposition, with high concentration of pollutants, in reservoirs for water supply. Legal nature-protection standards are weakly implemented in regional ski areas. Effective protection of landscape in Serbian ski-areas is based on careful considerations of impact assessment at all levels of planning (spatial and urban planning) and designing activities, which enables application of restoration concept, in accordance with general goals of environmental protection (preserving biodiversity, CO2 sequestration, attenuation of effects of global climate changes).