A common methodology for risk assessment and mapping for south-east Europe: an application for heat wave risk in Romania

This paper reports on a quantitative estimation of the risk to residents at the toe of Mount Albino, a carbonatic relief covered by shallow deposits of pyroclastic soils, which threatens the municipality of Nocera Inferiore (southern Italy). The quantitative risk analysis (QRA) focuses on one type of mass transport phenomena typical for the context at hand, namely the hyperconcentrated flows. The methodological approach includes three main steps: hazard analysis, consequence analysis and risk estimation. Based on historical incident data, the hazard analysis makes use of a high-resolution digital terrain model and advanced models that incorporate relevant geological and geotechnical input data collected via in situ investigations and laboratory tests. The consequence analysis takes into account information on the exposed persons (age, gender) and their vulnerability. The estimated risk to life is calculated at the individual level (risk to the average and most exposed person). The reported procedure is one of the first QRA’s applications to instabilities which potentially affect natural slopes in Italy, and it was successfully used as technical basis for a public participatory process in Nocera Inferiore, designed and developed to support decisions about risk mitigation measures.     

On the period variability of GP andromedae

The present paper deals with the pulsation period variability of the high-amplitude δ Scuti star GP Andromedae using a data set covering a time base of 26.9 years. The possibility of a periodic component (reflecting the light-time effect induced by a hypothetic binarity) in the O-C curve is inferred. The presence of this periodicity in the period variation of GP And leads to a diminution of the discrepancy between predicted and observed relative period change rates. The hypothesis of the existence of an unseen companion is discussed. The statistical analysis of the final O-C residuals distribution, indicates their normal or close to normal character. This revised version was published online in July 2006 with corrections to the Cover Date.     

The impact of climatic and non-climatic factors on land surface temperature in southwestern Romania

Land surface temperature is one of the most important parameters related to global warming. It depends mainly on soil type, discontinuous vegetation cover, or lack of precipitation. The main purpose of this paper is to investigate the relationship between high LST, synoptic conditions and air masses trajectories, vegetation cover, and soil type in one of the driest region in Romania. In order to calculate the land surface temperature and normalized difference vegetation index, five satellite images of LANDSAT missions 5 and 7, covering a period of 26 years (1986–2011), were selected, all of them collected in the month of June. The areas with low vegetation density were derived from normalized difference vegetation index, while soil types have been extracted from Corine Land Cover database. HYSPLIT application was employed to identify the air masses origin based on their backward trajectories for each of the five study cases. Pearson, logarithmic, and quadratic correlations were used to detect the relationships between land surface temperature and observed ground temperatures, as well as between land surface temperature and normalized difference vegetation index. The most important findings are: strong correlation between land surface temperature derived from satellite images and maximum ground temperature recorded in a weather station located in the area, as well as between areas with land surface temperature equal to or higher than 40.0 °C and those with lack of vegetation; the sandy soils are the most prone to high land surface temperature and lack of vegetation, followed by the chernozems and brown soils; extremely severe drought events may occur in the region.     

Biperiodic orbital period modulation of the W UMa binary system CK Bootis

A study of the orbital period variation of the W UMa system CK Bootis is made using an extended observational time base. The biperiodicity of the orbital period modulation is emphasized. Both detected periodicities (24.14 yr and 10.62 yr) cannot be explained through the light-time effect unless the companion would be a white dwarf as suggested by other authors, too. Moreover, we also argue that, nowadays at least, it seems that there is no causal relation between the orbital period variation and the recently discovered visual companion. Consequently, we infer that at least one of the two periodicities may be related to the magnetic activity cycles in the component stars of CK Boo, while the other periodicity could be related to the presence of a fourth companion in the system.     

The Stability of the Light Curve of DL Cassiopeiae Between 1959–1997

A variability survey on the shape of the light curve of the classical Cepheid DL Cas has been performed on the basis of Johnson V photometry data covering about 38 years. The input parameters (mean magnitude, pulsation frequency and period, light curve amplitude, harmonics amplitudes, Fourier type structural parameters) for our study were determined through the Fourier decomposition technique applied to each data set. The analysis of the outcoming time series, using different and complementary methods, seems to indicate the constancy of these parameters within the precision limits of the available data, although the hypothesis of the presence of a low level variability cannot be excluded. The only exception is the pulsation period, which displays a possible increasing trend with a rate of 0.109 ± 0.037 s yr⁻¹. This trend may be, at least partly, an effect of the unequal precision of pulsation period estimated values, corresponding to each considered data set. This revised version was published online in July 2006 with corrections to the Cover Date.     

Assessment of vulnerability for rockfalls in Cozia Gorge (Southern Carpathians,Romania)

Natural Hazards - Rockfalls represents a sudden, extremely important geomorphological hazard and may become a threat for people’s life, as well as goods and transport. The present study aims...