Emiliya Velizarova(1), Rumen Nedkov(2), Ibrahim Molla(1), Mariana Zaharinova(2), and Boyka Malcheva(3)

1. Department of Forest Ecology, Forest Research Institute - BAS, 132 St. K. Ohridski Blvd., 1756 Sofia, Bulgaria. E-mail: velizars@abv.bg
2. Department of Aerospace Information, Space Research and Technology Institute - BAS, Acad. G. Bonchev Str. Bl. 1, 1113 Sofia, Bulgaria. E-mail: rnedkov@space.bas.bg; marianaz@space.bas.bg
3. Department of Soil Science, University of Forestry, 10 St. K. Ohridski Blvd., 1797 Sofia, Bulgaria. E-mail: boika.malcheva@gmail.com
 

Forest fires in Bulgaria are frequent in recent years, especially when summer droughts are prolonged. The carbon biogeochemical cycle is the most sensible to forest fires. The goal of the present investigation was to study the changes in the quantity and stocks of soil organic carbon in result of the forest fire, occurred on the territory of Biosphere Reserve (BR) 'Bistrishko branishte' and 'Vitoshko lale' in Vitosha Mountain during the summer of 2012. Both territories of Vitosha Natural Park, affected by fires in year 2012 have been mapped. It was established that the total carbon content in the soils in Biosphere Reserve 'Bistrishko branishte' and 'Vitoshko lale' area decreased significantly as a consequence of the fire. This diminution is more substantial for Biosphere Reserve 'Bistrishko branishte' - about 7 %. The fires have led to a significant decrease of organic carbon stocks (ΔSOCstock) in both regions - respectively with about 22 tC.ha-1 for BR 'Bistrishko branishte' and from 8.0 tC.ha-1 to 25 tC.ha-1 for 'Vitoshko lale'. In only one sampling area in 'Vitoshko lale', an increase in the carbon stocks by about 10 tC.ha-1 has been registered. 

Dilyana Yordanova*  and Vanya Kyoseva

Department of Environmental Engineering, University of Chemical Technology and Metallurgy, 8 St. K. Ohridski Blvd., 1797 Sofia, Bulgaria. E-mail: dilyana.yordanova@outlook.com*, vanya_kyoseva@uctm.edu
 

Food waste is a serious global problem that leads to negative environmental, social and financial impacts. Worldwide losses of food in the stages of production, transportation, retail and consumption of food are significant - a third of the annual production output falls in the waste stream. A quantification of food waste in the country is presented in the paper. An analysis of the possibilities for sustainable management of food waste in Bulgaria by introducing measures to prevent its generation, separate collection implementation and application of proven technologies such as composting and anaerobic digestion, to ensure protection of the environment and human health is done. 

Anton Stoimenov(1), Radka Koleva(2), Ventzeslav Dimitrov(1), Youlin Tepeliev(2), Todor Lubenov(1), and Julia Kroumova(3) 

1. Space Research and Technology Institute - BAS, Acad. G. Bonchev Str. Block , Sofia, Blgaria.
2. Uniersity of Forestry, limet hridski Bld., Sofia, Blgaria. E-mail: rad_koleva@abv.bg, rad.koleva@gmail.com;
3. National Institute of Geophysics, Geodesy and Geography - BAS, Acad. G. Bonchev Str. Block , Sofia, Blgaria.

CORINE Land Cover 2012 Bulgaria is a part of the Pan-European project CORINE Land Cover (CLC). Experts from 39 countries participate in this GMES/Copernicus program's project. The main aim of the project is to identify and map the changes of land cover/land use for the period 2006-2012 using multitemporal/multispectral satellite imagery. Harmonized methodology with a 44 class nomenclature and a computer assisted photo-interpretation are applied for creating a geospatial database of Bulgarian territory for the year 2012. In addition to the CLC work, a task for evaluation of fie igh esoltio Layers (L) is iclded. hey are comlemetary to CLC ad roide iformatio o secific lad coer characteristics degree of imeriosess forest, ermaet grasslands, wetlands and permanent water bodies. A brief description of the applied methodology and the main results achieved are presented. The whole Bulgarian territory is mapped in details adequate for the 1:100 000 scale with a minimum mapping unit of 25 ha and a minimum change area of 5 ha. For the investigated period (2006-2012) dominant changes are observed in forests and semi-natural areas -  27,628 ha or 54.65 % of all changes, followed by agricultural lands (21 618 ha or 42.76 %). The statistical analysis of the created databases and a comparison between main land cover changes for the 1990-2000, 2000-2006 and 2006-2012 time periods are discussed. The average annual land cover change rate is 0.17 % which positions Bulgaria among the majority of the European countries having relatively small land cover changes. 

Ivan Ts. Marinov 

Department of Forest Ecology, Forest Research Institute - Bulgarian Academy of Sciences, 132 St. Kliment Ohridski blvd., Sofia 1756, Bulgaria. E-mail: marinovbg02@yahoo.com
 

A methodology for determining of ecological conditions in forest ecosystems in order to assess their future variations under expected climate change has been developed. Complex index for ecological conditions (Kec) was established including hydrothermal (precipitations, temperature and duration of drought period in the region), soil (depth and erosion) and relief (exposure and inclination of slope) parameters. The expected changes of climatic elements were assessed based on data from climatic scenarios. Model verification was performed for Sedelska River basin, a tributary of Struma River, South-western Bulgaria. Distribution and division into 5 groups of main tree species within the watershed area was performed in accordance to the values of Kec. Distribution of forest ecosystems in groups according to expected ecological conditions for the period of 2021-2049 and 2071-2099 was established and their spatial distribution for Sedelska River basin was mapped. It was established that nowadays about 30 % of stands and forest plantations are in the first group - under 'bad' ecological conditions. The results showed that for the period 2021-2049 the area of these forests will increase and will reach 36.9 %, and for the period 2071-2099 more than the half of these forest ecosystems (51.2 %) will be under 'bad' ecological conditions. 

Svetla Angelova* and Evgeni Sokolovski

Department of Environmental Engineering, Faculty of Chemical and System Engineering, University of Chemical Technology and Metallurgy, 8 Kl. Ohridski blvd., 1797 Sofia, Bulgaria. *E-mail: svetleto_007@abv.bg
 

The paper analyses treatment options for sewage sludge generated in wastewater treatment plants and the available options for its recovery and disposal in the country. In parallel, a review of existing legislation concerning the use/utilization of sewage sludge for various purposes is done. Currently, treatment of sludge generated in the Republic of Bulgaria is mainly carried out through landfill or improper disposal and a very small quantity is used in agriculture. The need to seek other approaches to the sustainable management of sewage sludge is defined by two main factors: increasing the amount of sludge from urban wastewater treatment and compliance with requirements of Directive 1999/31/EC on the landfill of waste to reduce the amount of biodegradable waste going to landfills. Given the availability of sufficient quantities of sludge from wastewater treatment plants (stabilised properly) they could be regarded as a valuable energy resource.