Time filter

Source Type

Balteanu D.,Romanian Academy of Sciences | Chendes V.,National Institute of Hydrology and Water Management | Sima M.,Romanian Academy of Sciences | Enciu P.,Romanian Academy of Sciences
Geomorphology | Year: 2010

This paper proposes a brief spatial analysis of landslides in Romania, completed by a landslide susceptibility model. Landslides constitute a very common geomorphic hazard in this country, mainly in the hilly regions which occupy around 30% of Romania's territory. The landslide susceptibility assessment at national level was accomplished using a Landslide Susceptibility Index (LSI) computed in GIS, which considers and weights the main factors that control landslide activity: lithology, slope gradient, maximum rainfall in 24 h, land use, seismicity and local relief. Each factor was classified into 7-18 classes which were rated from 1 to 10 by means of expert judgement. A formula was devised to compute the Landslide Susceptibility Index over each 100 m × 100 m pixel and the resulting values were ranked into 5 landslide susceptibility classes. This synthetic method of landslide susceptibility assessment, applied to the whole country, is a useful tool to evaluate the distribution of landslide-prone areas, as well as to validate and to enhance some results obtained in previous studies based on field research and map interpretation. The most landslide-prone areas correspond to the Subcarpathians (an outer fringe of hilly terrain accompanying the Carpathians), as well as to the Moldavian Plateau in the east. The semi-quantitative approach has been validated with satisfactory results in a particular sector using independent cartographic landslide inventories. © 2010 Elsevier B.V. Source

Trifu M.C.,National Institute of Hydrology and Water Management
11th International Multidisciplinary Scientific Geoconference and EXPO - Modern Management of Mine Producing, Geology and Environmental Protection, SGEM 2011 | Year: 2011

The paper present the LIFE09 ENV/RO/000612 - CLEANWATER project, which foresees the development of an integrated approach for the management of nitrogen pollution, within the river catchments, with emphasis on modelling tools for delimiting the nutrients vulnerable zones, as well as for analyzing the proper measures from the environmental and economical point of view. The Barlad River Basin (surface of 7220 km2, mean altitude 211 m) represents 17% of the surface of Siret river basin, which is the biggest Romanian river basin, characterized by a great number of agricultural sources and nitrate vulnerable zones. The effects of land use planning options, at river basin scale, are analyzed in the framework of the project, by an entirely computerized system. The system includes several software modules that calculate the environmental impact of human activities, a GIS platform to which all the data is sent and serves as common ground for processing and interpret the results offered. Evaluation of human impact using GIS environment offers a global view of the pollution problems at the basin scale and will improve the local and central authorities' analysis in the field of nutrient management, especially the waters polluted or threatened by nitrogen pollution. By choosing a modelling approach combined with current monitoring, the proposed GIS system could be able to answer different environmental questions such as: the impact of existed pollution sources especially on the phreatic aquifers that assure the drinking water supply, the synergy between maninduced changes and climatic changes and hydrological related, the contributions of different sources (point and diffuse sources) to the N and P input to the waters quality, making the deference between agricultural source and others sources(e.g. 77% of the population reject the wastewater directly in the soil). In spite of others European approaches based on use of descriptive parameters and afferent weight system, the CLEANWATER project integrates a holistic view on the water management, being based on a river basin approach that allows handling in the most effective way different activities affecting the quality and the quantity of the water. The proposal allows simulating both surface and groundwater systems and their interaction, making available conjunctive modelling of surface, soil and groundwater. Using modelling approach it is possible to separate the various types of pollution sources (agriculture, industry, localities) in actual and future environmental conditions. © SGEM2011 All Rights Reserved by the International Multidisciplinary Scientific GeoConference SGEM. Source

Ionita M.,Alfred Wegener Institute for Polar and Marine Research | Boroneant C.,Rovira i Virgili University | Chelcea S.,National Institute of Hydrology and Water Management
Climate Dynamics | Year: 2015

The relationship between the seasonal modes of interannual variability of a multiscalar drought index over Europe and the large-scale atmospheric circulation and sea surface temperature (SST) anomaly fields is investigated through statistical analysis of observed and reanalysis data. It is shown that the seasonal modes of dryness and wetness variability over Europe and their relationship with the large-scale atmospheric circulation and global SST anomaly fields differ from one season to another. During winter, the dominant modes of dryness and wetness variability are influenced by the Arctic Oscillation (AO)/North Atlantic Oscillation (NAO), the Scandinavian pattern, the East Atlantic pattern and the East Atlantic/Western Russia pattern. The spring dryness/wetness modes are influenced mainly by the AO, Polar/Eurasian patterns and the Atlantic Multidecadal Oscillation conditions. The phases (positive or negative) and the superposition of these large scale variability modes play a significant role in modulating the drought conditions over Europe. During summer, the atmospheric blocking is one of the main drivers of dryness and wetness conditions, while during autumn dryness/wetness conditions variability can be related to the NAO or with a wave train like pattern in the geopotential height at 850mb, which develops over the Atlantic Ocean and extends up to Siberia. It is also found that the response of the dryness and wetness conditions to global SST is more regional in summer, compared to the other seasons, when local processes may play a more important role. © 2015 Springer-Verlag Berlin Heidelberg Source

Ionita M.,Alfred Wegener Institute for Polar and Marine Research | Rimbu N.,Alfred Wegener Institute for Polar and Marine Research | Rimbu N.,University of Bucharest | Chelcea S.,National Institute of Hydrology and Water Management | Patrut S.,University of Bucharest
Theoretical and Applied Climatology | Year: 2013

We investigate the multidecadal variability of summer temperature over Romania as measured at 14 meteorological stations with long-term observational records. The dominant pattern of summer temperature variability has a monopolar structure and shows pronounced multidecadal variations. A correlation analysis reveals that these multidecadal variations are related with multidecadal variations in the frequency of four daily atmospheric circulation patterns from the North Atlantic region. It is found that on multidecadal time scales, negative summer mean temperature (TT) anomalies are associated with positive sea level pressure (SLP) anomalies centered over the northern part of the Atlantic Ocean and Scandinavia and negative SLP anomalies centered over the northern part of Africa. It is speculated that a possible cause of multidecadal fluctuations in the frequency of these four patterns are the sea surface temperature (SST) anomalies associated to the Atlantic Multidecadal Oscillation (AMO). These results have implications for predicting the evolution of summer temperature over Romania on multidecadal time scales. © 2012 Springer-Verlag Wien. Source

Ionita M.,Alfred Wegener Institute for Polar and Marine Research | Ionita M.,University of Bremen | Lohmann G.,Alfred Wegener Institute for Polar and Marine Research | Lohmann G.,University of Bremen | And 5 more authors.
Climate Dynamics | Year: 2012

Interannual to decadal variability of European summer drought and its relationship with global sea surface temperature (SST) is investigated using the newly developed self calibrated Palmer drought severity index (scPDSI) and global sea surface temperature (SST) field for the period 1901-2002. A European drought severity index defined as the average of scPDSI over entire Europe shows quasiperiodic variations in the 2.5-5 year band as well as at 12-13 years suggesting a possible potential predictability of averaged drought conditions over Europe. A Canonical Correlation Analysis between summer scPDSI anomalies over Europe and global SST anomalies reveals the existence of three modes of coupled summer drought scPDSI patterns and winter global SST anomalies. The first scPDSI-SST coupled mode represents the long-term trends in the data which manifest in SST as warming over all oceans. The associated long-term trend in scPDSI suggests increasing drought conditions over the central part of Europe. The second mode is related to the inter-annual ENSO and decadal PDO influence on the European climate and the third one captures mainly the drought pattern associated to Atlantic Multidecadal Oscillation. The lag relationships between winter SST and summer drought conditions established in this study can provide a valuable skill for the prediction of drought conditions over Europe on interannual to decadal time scales. © 2011 Springer-Verlag. Source

Discover hidden collaborations