Remus Prăvălie
University of Bucharest
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Remus Prăvălie.
Arid Land Research and Management | 2015
Remus Prăvălie; Georgeta Bandoc
The present study constitutes a climatic approach of aridity trend analysis in the south-eastern part of Romania (Dobrogea region), over the past five decades. The analysis is based on a series of investigations on the temporal trends of certain climatic parameters that play a key role in a territorys climatic variability, such as temperature, precipitation, and potential evapotranspiration. In this respect, a series of aridity index trends (De Martonne Index, UNEP Index, and Water Deficit Index), recorded between 1961 and 2009, was analyzed, using climatic parameters provided by eight weather stations in the Dobrogea region. While the results showed that the last five decades were generally characterized by an upward climatic aridity trend (increasing temperatures and potential evapotranspiration in all considered instances), there are certain regional differences due to precipitation regime variations (higher rainfall values were recorded at four weather stations). In terms of maximum aridity conditions, the study reveals that the most critical aridity index values were reported in 1990, 2000, 2001, 2003, and 2008, especially at the weather stations located in the northern part of the Dobrogea region. The situation is slightly different in the central-southern part, where the results indicated an aridity trend decline coupled with an increase of annual precipitation amounts, especially between 1995 and 2009.
Journal of Geographical Sciences | 2015
Georgeta Bandoc; Remus Prăvălie
The analysis of a territory’s climatic water balance dynamics against the background of climate change is a key component for increasing water resource management efficiency. The present study aims to analyse climatic water balance (CWB) dynamics in Romania’s most arid region, Dobrogea, located in the southeast. The study covers the 1961–2009 period, and is based on annual and seasonal CWB values (mm), provided by nine weather stations located throughout the region. The study, based on statistical and GIS techniques, is divided into two main stages, both carried out at annual and seasonal scales–trend analysis using the Mann-Kendall test, the Sen’s slope method, and CWB value distribution type analysis. In order to identify the probabilistic types of distributions, four mathematical models were identified–Pearson, Gamma, Chi-Squared and Wakeby, statistically verified with the P-P Plot, Q-Q Plot and Probabillity Difference Graph (PDG) curve tests. Thus, in terms of trends, the results showed a deficit increase especially at the northern stations, mainly for annual values (with a peak in the northeast, where CWB rates reached –3.2 mm/yr). While general CWB declines occurred in winter, spring and summer, apparent decrease rates were found in the northern region (highest negative rates–summer, northwest, –1.4 mm/yr). Autumn is an exception, due to overall increase rates which peaked in the southwest (2.3 mm/yr). However, the entire trend analysis indicated a general lack of statistical significance. The distribution type histogram analysis showed that, annually and seasonally, deficit values are generally dominant (more noticeable in the northern region), except for the winter season, mainly characterized by surplus intervals. Thus, the results suggest a climatic water deficit increase over the last five decades especially in northern Dobrogea, which signals the need for a spatial prioritization targeting a more efficient water resource management, necessary first and foremost for increasing regional agricultural system productivity.
Arid Land Research and Management | 2016
Remus Prăvălie; Cristian Valeriu Patriche; Igor Sîrodoev; Georgeta Bandoc; Monica Dumitraşcu; Daniel Peptenatu
ABSTRACT Water deficit (WD) typically associated with drylands and poor land use currently represent a major limiting factor for agricultural systems in numerous regions of the world. The present study aims to analyze the relationship between water deficit and corn (Zea mays L) crop yields in southern Oltenia drylands. The study includes the post-1990 period, which is representative for Romania in terms of ample climate changes and poor land planning decisions affecting water resources. This analysis targeted the vegetation period of corn (April–September), the reference period covering a 14-year interval, from 1990 to 2003. The entire analysis was based on spatialized WD data (mm), obtained by interpolation methods used on climate data provided by regional weather stations, and agricultural yield data (tons/hectare/year), recorded in 113 administrative territorial units. Both data sets were analyzed in terms of interannual statistical relationships, established in compact climate zones delineated by Thiessen-Voronoi polygons. The results showed a clear statistical relationship between the two variables, with an average dependence of corn yields on water of approximately 65%. The range was from 55 to 78%, depending on region. The results showed an average yield decrease of 16.5 kg/ha/year for each mm rise of the WD, or loss of 1.65 t/ha/year when considering a deficit rise of 100 mm. Therefore, in the context of increasing future WD, urgent action is needed in order to reintroduce irrigation systems.
Journal of Environmental Management | 2018
Remus Prăvălie; Georgeta Bandoc
For decades, nuclear energy has been considered an important option for ensuring global energy security, and it has recently started being promoted as a solution for climate change mitigation. However, nuclear power remains highly controversial due to its associated risks - nuclear accidents and problematic radioactive waste management. This review aims to assess the viability of global nuclear energy economically (energy-wise), climatically and environmentally. To this end, the nuclear sectors energy- and climate-related advantages were explored alongside the downsides that mainly relate to radioactive pollution. Economically, it was found that nuclear energy is still an important power source in many countries around the world. Climatically, nuclear power is a low-carbon technology and can therefore be a viable option for the decarbonization of the worlds major economies over the following decades, if coupled with other large-scale strategies such as renewable energies. These benefits are however outweighed by the radioactive danger associated to nuclear power plants, either in the context of the nuclear accidents that have already occurred or in that of the large amounts of long-lived nuclear waste that have been growing for decades and that represent a significant environmental and societal threat.
Journal of Earth System Science | 2015
Liliana Zaharia; Romulus Costache; Remus Prăvălie; Gabriel Minea
Flood risk assessment is an important component of risk management. Given this context, this paper aims to identify and map areas with high potential for flash-floods and flooding occurrence, at different spatial scales (from catchment to local scale), in order to estimate the flood/flooding vulnerability. The paper is based on three main methods, which were applied in the Slănic River catchment (427 km2), located in the external curvature region of the Romanian Carpathians: (i) statistical analyses; (ii) determination and mapping of some indices to assess the flash-flood and flooding potential (FFPI and respectively FPI) and (iii) hydraulic modelling. The data used mainly include hydrological statistics (maximum monthly and annual discharges, flood-related data) and spatial data on catchment geographical characteristics (hypsometry, geology, soils, land use) obtained or derived from various sources (maps, aerial images, digital databases, field measurements) which were integrated into the GIS environment. The aforementioned methods helped to (i) highlight specificities of floods in the Slănic catchment (magnitude, frequency, flood waves characteristics); (ii) identify areas with high potential for flash-floods and flooding at the catchment spatial scale; (iii) assess the structural vulnerability in the Cernăteşti village, by simulating flood-prone areas for flood peaks with exceedance probability of 1%, 5% and 10%. The results could lead to a better knowledge and understanding of flood characteristics in the study area, in order to mitigate the flood risk through a more effective management, both at the catchment scale, as well as local scale (in the Cernăteşti village).
Frontiers of Earth Science in China | 2017
Liliana Zaharia; Romulus Costache; Remus Prăvălie
Given that floods continue to cause yearly significant worldwide human and material damages, flood risk mitigation is a key issue and a permanent challenge in developing policies and strategies at various spatial scales. Therefore, a basic phase is elaborating hazard and flood risk maps, documents which are an essential support for flood risk management. The aim of this paper is to develop an approach that allows for the identification of flash-flood and flood-prone susceptible areas based on computing and mapping of two indices: FFPI (Flash-Flood Potential Index) and FPI (Flooding Potential Index). These indices are obtained by integrating in a GIS environment several geographical variables which control runoff (in the case of the FFPI) and favour flooding (in the case of the FPI). The methodology was applied in the upper (mountainous) and middle (hilly) catchment of the Prahova River, a densely populated and socioeconomically well-developed area which has been affected repeatedly by water-related hazards over the past decades. The resulting maps showing the spatialization of the FFPI and FPI allow for the identification of areas with high susceptibility to flash-floods and flooding. This approach can provide useful mapped information, especially for areas (generally large) where there are no flood/hazard risk maps. Moreover, the FFPI and FPI maps can constitute a preliminary step for flood risk and vulnerability assessment.
Journal of Earth System Science | 2016
Remus Prăvălie; Liliana Zaharia; Georgeta Bandoc; Alexandru I Petrişor; Oana ionuş; Iulian Mitof
The present paper examines hydroclimatic dynamics in southwestern Romania drylands, which is one of the country’s most heavily affected regions by climate change. The analysis focuses on two of the region’s representative catchments (Drincea and Desnatui), covers the past five decades (1961–2009), and is based on climate data (mean monthly and annual climatic water balance values – CWB, expressed in mm) and hydrological data (mean monthly and annual streamflow rate values – SFR, expressed in m3/s). The data were provided by five regional weather stations, i.e., by five gauging stations located within the two catchments. The analysis was conducted on three temporal scales (annual, seasonal and monthly), and used statistical methods, such as Mann–Kendall test/Sen’s slope method for trend analysis, and Spearman/Student test for the statistical association between climatic and hydrological parameters. The results indicated an overall increase in climatic water deficit, with direct effects on streamflow reduction. Statistically significant trends (climatic water deficit increase and streamflow decrease) were identified especially in spring (with maximum rate values of (−1.66 mm/yr)/(−81.3 mm/49 yrs), for the CWB, and (−0.02 m3/s/yr)/(−0.9 m3/s/49 yrs), for the SFR). In some cases (mainly in the autumn months) it was found that, while climatic water deficit has decreased, the streamflow rate has increased. Statistical correlations revealed the relationship between the considered hydroclimatic parameters, with a particularly high statistical significance in spring and summer. Weak and inverse correlations between climatic and hydrological parameters can be explained by the role of other factors controlling the streamflow, both natural (soil and lithology) and anthropogenic (wetland drainage, water body conversion, dam and reservoirs building).
GEOREVIEW: Scientific Annals of Stefan cel Mare University of Suceava. Geography Series | 2013
Remus Prăvălie
The present study examines the spatial and temporal dynamics of forest and vineyard areas in the last three decades in areas occupied by sandy soils in southern Oltenia. Areas with sandy soils in this zone are considered vulnerable elements of the environment as a result of deflation phenomenon that occurs after the disappearance of vegetation. It is therefore necessary to analyze the current state of sandy soils covered by forest vegetation and vineyards, these two categories of vegetation playing a vital role in their stabilization. The results obtained show that in the last three decades forest areas decreased by approx. 2700 ha (11.6%) being replaced by sandy soils, while vineyards areas have diminished with 22% (1638 ha), with negative consequences of ecological, climatic and social nature
Earth-Science Reviews | 2016
Remus Prăvălie
Catena | 2017
Remus Prăvălie; Ionuţ Săvulescu; Cristian Valeriu Patriche; Monica Dumitraşcu; Georgeta Bandoc