Nadka Ignatova1, Sonya Damyanova1, Radka Fikova2

1University of Forestry – Sofia; 2Central Laboratory of General Ecology – Bulgarian Academy of Sciences

Critical loads of Mercury have been determined for forested catchments in Bulgaria for the first time, using Steady State Mass Balance Method. The uptake of Mercury by the biomass as well as the leaching of Mercury by the runoff have been used in the calculating procedure taking into account the critical level of Mercury in the soil solution equal to 1 μg.dm-3. Critical loads are considered as depositions of Mercury bellow which harmful effects for a given forested catchment are not expected. Exceedences of critical loads of Mercury by its real deposition have been calculated for 2007. It has been found that the values of critical loads of mercury are lower for catchments with broad leaved forests ranging between 25.25 and 36.39 g.ha-1.yr-1, comparing to the coniferous forests (33.40–61.11 g.ha-1.yr-1). The real depositions of Mercury in the forested areas in Bulgaria are very low situated between 0.10 and 0.88 g.ha-1.yr-1 which means that there are not any risks of damage of forested catchments in Bulgaria by Mercury depositions.

Ivanka Koleva-Lizama1, Bernardo Lizama Rivas2

1University of Foresty â€“ Sofia, 2National Institute of Meteorology and Hydrology – BAS

In recent years there have been anumber of significant riverine floods all around the World which caused enormous damage both in terms of loss of life and economics. The problem of the floods control and the possibilities to surmount the consequences from similar crisis situations is necessary to solve. In fact,of all natural risks,floods pose the most widely distributed risk to life today. The objective of this paper is to examine the possibilities to integrate the necessary datafor crisis situation analysis created by floods,and in the future these dataserve as an information base for application of GIS-Technologies and adaptation of mathematical models.

Ivanka Koleva-Lizama1, Bernardo Lizama Rivas2

1University of Foresty – Sofia, 2National Institute of Meteorology and Hydrology – BAS

The watershed analysis requires the integration of knowledge, data and simulation models to solve practical hydrological problems. The main objective of this study is to simulate the streamflow of the Vrana River, using the SWAT model. AGIS-based hydrologic modeling toolkit called the Automated Geospatial Watershed Assessment (AGWA) tool has been used. The calibration was achieved by estimating the model parameters and evaluating convergence between simulated and observed discharges by using mainly the Nash & Sutcliffe coefficient. The obtained results of runoff simulation can be accepted as satisfactory.

Krasimira Staneva1, Gergana Georgieva2

1Sofia University St. Kliment Ohridski, 2Intergeo Technology

Objective of this development is to examine the geochemical state of soils and groundwater in urban area, strongly influenced by the presence of gas stations. In the region of the gas station Plovdiv, "center" after preliminary studies summarized in the phase 0 (the incident documented events, technical malfunctions of the site and assess the risk of contamination with petroleum products) was carried out prior field study (phase I), whose results are reflected in this report and they served to develop a plan for subsequent Phase II trials. Field work was conducted in August 2006 and 2007. 

Mariana Doncheva-Boneva

University of Forestry – Sofia

Data on mean annual, mean monthly, mean 24 hour period and max 1 hour concentrations of SO2, NOx, O3, PM10 were presented. The measurements were performed during 2005–2007 in the area of Maritza Iztok. The results showed higher SO2 pollution in the region of Galabovo with annual concentrations exceeding the adopted air quality limit values 1.1 to 2.7-fold. The mean annual concentration of PM10 varies between 30–38 μg/m³, values exceeding the air quality limit values (20 μg/m³) adopted after 2008.