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To evaluate hydrological drought in small basin was used minimum flow parameters like percentiles from the flow duration curve, mean annual minimum flow, base flow index and recession index. Water deficit was estimated based on threshold level method and the sequent peak algorithm. Each method was exemplified using data from hydrometric stations from small basins included in Bahlui drainage basin. The results show that in the period between 1950 and 2014, the average drought duration of the cold season is over 20 days, but with a low water deficit due to conditions of quartering it in the form of ice and snow layer. In summer season, the average duration of hydrological drought is over 25 days, with a huge water deficit which may exceed 37.5 mil. m³ as happened, for example in the summer of 2012 in Bahluet catchment. [ABSTRACT FROM AUTHOR]

The paper analyzes some characteristics of annual and seasonal amounts of rainfall recorded in 24 hours in Romania. Annual and seasonal frequency distribution of rainfall quantities registered in 24 hours, air circulation type regarding these events, and the return periods of the absolute maximum values have been analyzed. Annual and seasonal values of maximum 24-hour precipitation amount from 23 weather stations from Romania, located between 3 and 661 m, have been considered over a period of 55 years (1961-2015). First, the data sets were tested using homogeneity distribution test at 99 % of significance level provided by XLSTAT software. HYFRAN software and HYSPLIT model have been employed in order to calculate statistics based on frequency analysis and to identify the atmospheric circulation type, respectively. The main findings are: absolute maximum annual rainfall quantities vary between 65.3 and 224.0 mm, with the highest values (over 120 mm) in the east and south-east part of the country; most of the weather stations have the highest annual frequency between 25- 50 mm, while winter, spring, and autumn are characterized by high frequency of 0-25 mm amounts; for the winter season, the maximum 24-hour precipitation has never exceeded 75 mm, in spring and autumn they are under the 125 mm threshold, while in summer locally exceeded 200 mm; the return periods of maximum annual quantities of rainfall are generally ranging between 32.2 and 387 years, highlighting the continental climate of some regions of the country; four types of air circulation have been detected, more frequent from south and southwest part of the Europe, bringing warm and moist air masses. [ABSTRACT FROM AUTHOR]

Continuously increasing urbanization of big cities worldwide is nowadays an important issue in urban development studies. One of the most significant consequences is the intensification of urban heat islands over the big cities. This study aims to detect the different surfaces temperature in Cluj-Napoca city, Romania, by using satellite data images and GIS specific methods. The paper is based on satellite images of Landsat 5 and Landsat 7 missions and provided by USGS (United States Geological Survey) database. The images that passed the cloud cover controlled are taken in the summer months (June, July, and August). To evaluate the surface temperatures, we combined the satellite data images processing with GIS techniques. They have been integrated in a surface temperature estimation model where the spectral radiance is converted into temperature values. Then the surfaces with temperature higher than 30ºC have been identified and their total area has been calculated. Erdas Imagine 2013 şi ArcMap 9.3 software have been used in processing the raster images. For a detailed investigation, temperature on two profiles over the city area was analyzed. The main findings of the paper are: there are important temperatures difference for various type of surfaces; the green areas and water bodies have the coldest surface temperature, which is usually 8 - 10 ºC lower compared to the hottest surfaces specific to built civil and industrial areas. [ABSTRACT FROM AUTHOR]

Heat waves are one of the most important extreme phenomena that are subject to important changes under present global warming conditions. In this study a complex analysis of heat waves over a period of 53 year (1961-2013) was performed. Daily maximum temperature data have been used in order to detect the heat waves based on 95th percentile threshold. Then the annual series of number of heat waves, their mean and maximum duration, as well as their cumulated duration have been constructed. The four series were then subject to trend detection by employing Mann-Kandall and Sen's slope methods. The main results are: statistically significant increase was detected in all four parameters time series considered; the maximum annual values of the parameters are about four times higher compared to the mean annual number calculated for the entire period. The estimated social and economical impact is important to be determined in terms of response at community level, institutional level as well as at individual level. The impact could first imply modification regarding the consumption of electricity and major differences in the daily consumption basket. Also, as a direct consequence of heat waves it is expected the hospitalization costs increase due to the number of heat induced casualties and a decrease in the work performance resulting in an estimated loss in Gross Domestic Product. [ABSTRACT FROM AUTHOR]

Changes in daily extremes events is one of the most important topic in climate literature and many studies have been conducted so far at local or regional scale worldwide. For the Romanian territory, only little research on this issue was done. In this article, the Carpathian and intra-Carpathians regions of Romania were considered. This study is focused on analyzing the trends of daily extreme temperature indices at a regional scale over a period of 50 years: 1961-2010. Data sets of daily minimum and maximum temperature recorded in 10 weather stations were analyzed. The main goal was to find changes in daily extreme temperatures by using a set of 9 indices adopted from the core indices developed by ETCCDMI with appropriate modifications to suit to the analyzed territory. The main results suggest that the climate has become warmer during the last decades. Trends of extreme temperature indices at the regional scale of Carpathians and intra-Carpathians areas are increasing for most of the indices calculated. It has been identified that both extreme daily maximum and minimum temperatures indices have increased in the analyzed areas. For all the indices related to hot temperature most trends are statistically significant. [ABSTRACT FROM AUTHOR]

The urban air quality is one of the most important issues has attracted the attention of many researchers worldwide because it's strong impact on human health. The present study is focusing on some important air quality indicators, in Cluj County, Romania: nitrogen oxides (NO, NO2, NOx). The data have been collected in five measurement points located in two different cities in Cluj County: four points in Cluj-Napoca and one in Dej. Cluj-Napoca is one of the most important city of Romania, with more than 320,000 inhabitants, while Dej was one of the most industrialized city of Cluj County, which has about 33,000 inhabitants. The recordings were extended over a period of 5 years (2009 - 2013), with daily data coverage. The data were obtained by using the chemiluminescence technique for all five points. The main results are: the highest concentrations have been recorded during the cold half of the year (October - March) when exceeding of the maximum allowed values may occur, associated to specific weather condition (low thermal inversions) and heating systems; the most polluted spots were identified in Cluj-Napoca city, in the industrial and high traffic areas. [ABSTRACT FROM AUTHOR]

As a consequence of the global warming we assist in the last decades at the intensification of extreme weather or hydrological events, such as droughts, hail storm or flash floods. This paper examines some spatial and temporal manifestations of maximum intensity of rainfall in the warm season, in Northwestern Romania. Diurnal variation, duration, and intensity of the maximum rainfall intensity as well as the return periods of the absolute values, the statistical probability of recording higher values and trends have been detected. Annual maximum intensity values of precipitation recorded in 14 weather stations over a period of 35 years (1975-2009) have been considered. HYFRAN and MAKESENS software have been employed for statistical analysis. The data sets were tested to check if they were identical and independent distributed at the 95% of significance level. The main findings are: maximum intensity extreme values varies between 5.0 and 10.1 mm/min; the highest frequency of rainfall maximum intensity is specific in the afternoon and in the evening; the frequency of events with certain maximum intensity duration dramatically decreases from 45.5 % for 1 minute period to 0.6 % in the case of those events lasting more than 8 minute; the return periods of absolute maximum intensities are generally ranging between 30 and 80 years, while the absolute minimum intensities have the return periods between 1.002 and 1.06 years; almost 80 % of the locations indicated increasing trends in the maximum intensity of rainfall. All these findings are very important for modeling the flash flood parameters [ABSTRACT FROM AUTHOR]

The importance of the study is justified by the grave consequences the blizzard from January 2010 had on the road, rail, maritime and air traffic in several counties in the eastern part of Bulgaria and south-eastern part of Romania. Numerous localities were left without electricity and the life of few persons was in danger. This study aims to analyze the events impact on the territory and its management in the two countries. It discusses the prevention and mitigation measures taken by Bulgarian and Romanian authorities. In order to understand the duration and intensity of this extreme weather phenomenon, the NCEP 850 and SLP analyses, the CEP numerical forecast model, the atmospheric soundings and temporal variations of meteorological parameters recorded by the Bulgarian and Romanian weather stations have been used [ABSTRACT FROM AUTHOR]