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Volume XV |

Volcanic Eruptions in South Europe and the Change of Carbon Dioxide Concentration – Case Study: “Moussala” Basic Environmental Observatory

Abstract: The volcanic eruptions are one of the most characteristic natural sources of CO2 in the atmosphere (IPCC, 1990, 2007). In order to study the effect of volcanic eruptions on the increased levels of CO2, we have used data from the Basic Environmental Observatory (BEO) “Moussala”, Bulgaria, for the period comprised between July 2007 and March 2015. The Carbon dioxide is not a health hazard gas and there is no established limit concentration by the Bulgarian and international law. In this study, we have accepted as extremely high values the values that exceed the 95th percentile of the distribution of the daily average values for the studied period. The days with exceeding CO2 concentration were analysed in terms of volcanic activity (Etna), which could affect the investigated area with the spread of air pollutants and also CO2. The simulations developed by the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model are used in order to describe the trajectory and dispersion of pollutant and products from eruptions of Etna in the atmosphere. A synchrony between the occurrence of days with extreme high concentration of CO2 in the atmosphere in the region of BEO “Moussala” and eruptions of Etna volcano was established in most of the investigated cases.
The analysis of the results from BEO “Moussala” confirms the impact of the volcanic eruptions and Etna volcano, in particular, for the increasing of CO2 concentration in the atmosphere. On the other side, it was established that the activity of Etna is not the only factor which has impact on the concentration of CO2. More detailed analyses concerning not only natural, but also anthropogenic factors have to be done in the future in order to clarify the reasons for the increasing concentration of CO2 in the atmosphere (IPCC, 2014).

Volume XV |

The Mediterranean Oscillation (MOI) and the Forest Fires in Romania in the Period 1986–2014

Abstract: The study examines the connection between the Mediterranean Oscillation (MOI) and the forest fires (the annual number of fires, the annual burned area and the average burned area per fire) in Romania in the period 1986–2014. Pearson’s correlation coefficient (R) was used for determination of the correlation connection. Two MOI datasets were used: MOI-1 (Algiers and Cairo) and MOI-2 (Israel and Gibraltar). Monthly, seasonal and annual values of MOI were used in the calculations. Results for the number of fires and MOI-1: the highest values of R (statistically significant at the level of p≤0.05) were obtained for April (–0.446) and June (0.423), and for summer (0.432). The annual burned area and MOI-1: the highest values of R (statistically significant at the level of p≤0.05) were obtained for April (–0.459), and for winter (0.406). The number of fires and MOI-2: the highest values of R (statistically significant at the level of p≤0.01) were obtained for June (0.556) and February (0.475), and for summer (0.507). The annual burned area and MOI-2: the highest values of R (statistically significant at the level of p≤0.05) were obtained for June (0.449) and February (0.439), and for summer (0.439). Results of the research could be used for the long-term forecast of forest fires in Romania. However, further investigations of the connection between forest fires and other climate indices are necessary.

Volume XV |

Shape characteristics of fluvial islets based on GIS techniques. A case study: the Danube’s islets between Giurgiu and Olteniţa

Abstract: This study aims to quantitatively characterize shape parameters of fluvial islets using GIS techniques. There were eight metrics selected for the analysis. For the automation of the workflow, all processing functions were joined into a single graphical model. For this case study we selected the Danube sector situated between the cities Giurgiu and Oltenita. We chose to track the evolution of the fluvial islets’ shapes from 1864 to 2010. Information was extracted from historical data sources such as maps and ortophotoplans. The graphical model created was run for each studied year.
The results show major changes in the aspect of fluvial islets along the Danube reach. Between 1864 and 2010 the number of islets slightly increased with the total area ranging from 21.19 kmp to 27.96 kmp. In the period studied, the shape turned from a rounded aspect to a more elongated one. Knowledge of the information on the shape of those landforms is relevant for river restoration strategies, nature conservations of islets and maintenance of the protected habitats.

Volume XV |

The Assessment of Artificial Water Surfaces Regeneration in Stachinez Swamps Protected Area by Using Remote Sensing and In–situ Data

Abstract: The Satchinez Swamps, a remnant of the swamps once specific for Banat Plain, is an ornithological reserve since 1942 and the habitat of many protected bird species. Draining works conducted in the seventies affected the reserve by decreasing the water surface area. Thirty-five years later, hydro-technical works aiming to restore the former aquatic surfaces within the buffer zone were conducted. Thus, in 2005 a water delivery canal from the discharge canal of Satchinez reservoir towards Balta Mare was built. The objective of this study is to assess the efficiency of the hydrological works carried out in 2005 by using temporal analysis of some normalized difference indexes derived from satellite images, in relation to precipitation data (recorded at Timisoara meteorological station) as an indicator for wetland restoration. We used geospatial data from different time periods: historical maps (1953, 1962 and 1984), orthophotos (1963, 1970, 2005 and 2012), oblique airphotos (2004) and 38 Landsat satellite scenes (1984-2015), two images per year, for the dry season respectively for the rainy season. We noticed a slight increase of the Normalized Difference Vegetation Index (NDVI) in Balta Mare and on the relict watercourse of Sicsău stream, which shows the expansion of reed and suggests an increase in soil moisture. During the dry season, for the period before the restoration works (1984 – 2004) there is a strong, very significant correlation between Normalized Difference Water Index (NDWI) and precipitations (r =0.7008, p = 0.0011). After 2005, this correlation no longer occurs (r = -0.1083, p <0.05), which demonstrates that precipitations are not the main water supply for Balta Mare anymore. For the 1984 – 2015 period, during rainy months the Modified Normalized Difference Water Index (MNDWI) indicate the presence of water in Balta Mare, but during the dry months, it demonstrates the lack of water which underlines the temporary character of this pond and confirms the field observations. We conclude that the restoration did not succeed in the rebuilding of the former water surfaces of Balta Mare, but has an effect in increasing the underground water level in this area followed by reed extension.

Volume XV |

Faunistic Study of the Tsibar Danube Island

Abstract: Tsibar Island is situated on the Bulgarian part of the Danube River, at 680 m of the Bulgarian and about 100 of the Romanian coast from 716 to 719 km along the river, with an area of 1.3 km2. The territory is covered mainly by riparian woodland. Because of its European importance to the protection of rare and threatened habitats, plants and animals, including birds, the island falls within the borders of proposed Natura 2000 sites under both the Birds and the Habitats Directives.
Part of the island is placed under strict protection as a menaged reserve “Ibisha”. In 1997 the territory was designated as an Important Bird Area by BirdLife International. In 2002 the reserve has been declared as a Ramsar site according to the international convention for the conservation of wetlands. Tsibar Island is of international importance defined by one of the largest mixed colony of herons and cormorants in Bulgaria. It is a site of global importance for the nesting Pygmy Cormorant (Phalacrocorax pygmeus) and White-tailed Eagle (Haliaeetus albicilla) and one of the most important sites in Bulgaria for the nesting of the Night Heron (Nycticorax nycticorax), Squacco Heron (Ardeola ralloides) and Spoonbill (Platalea leucorodia). There have been identified more than 100 animal species: 42 terrestrial and 16 aquatic invertebrates, 5 fish species, 1 amphibian and 1 reptile species, 30 birds (including 22 breeding), 16 mammalian species (including 8 species of bats). Ascertained are the Medicinal leech (Hirudo verbana), which is a rare species at the European level, endangered Thick-shelled river mussel (Unio crassus), protected fish Asp (Leuciscus aspius) and Great raft spider (Dolomedes plantarius), included in the Red Data Book of Bulgaria in the category “extinct”. A management plan for Ibisha Menaged Reserve was developed in 2015.