National Institute of Hydrology and Water Management

Bucharest, Romania

National Institute of Hydrology and Water Management

Bucharest, Romania

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Risnoveanu G.,University of Bucharest | Chiriac G.,National Administration Apele Romane | Moldoveanu M.,University of Bucharest | Moldoveanu M.,National Institute of Hydrology and Water Management
Ecological Indicators | Year: 2017

Successful implementation of the Water Framework Directive and achieving its objective of good ecological status of all water bodies depend on the power of the set of monitoring indicators to capture the change in the ecological status of aquatic systems. In this context, testing the robustness and sensitivity of ecological indicators currently used for assessing the status of lotic water bodies is instrumental for the adaptation and further development of assessment methods. This is also a prerequisite for an effective, context-based monitoring system and for improving the quality of the decision making for water bodies. This is particularly challenging in regions where the sets of indicators are under development, the data series are relatively short and data which addresses the individual error sources are lacking. Here we show that hierarchical clusters and ordination analysis provide appropriate tools with which the validity of the ecological status of water bodies set up based on biological multimetric monitoring indices in a small water basin could be tested. We hypothesize that robust and informative monitoring methods classify all water bodies belonging to a single ordination grouping in the same quality class (high, good, moderate, poor or bad). In our case study multimetric biological indicators failed to discriminate between the good and moderate ecological status. Community structure as well as water conductivity and nitrate load were primarily responsible for the observed difference between ordination groupings. Inconsistencies shown in our case study are likely to be induced by insufficient refinement of monitoring schemes and by the constraints existing in the data series and available metadata. We show that multiplication of indicators leads to discrepant interpretation and problematic application. Proposed ordination analysis proves to be a simple and useful tool to detect such discrepancies and support further progress in indicator development. Integrated and longer data and metadata series are needed to refine context-based monitoring methods. © 2016 Elsevier Ltd


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.


Ionita M.,Alfred Wegener Institute for Polar and Marine Research | Chelcea S.,National Institute of Hydrology and Water Management | Rimbu N.,University of Bucharest | Adler M.-J.,National Institute of Hydrology and Water Management
Journal of Hydrology | Year: 2014

In this study we have examined the spatial and temporal variability of winter (DJF) streamflow over Romania as recorded at 46 hydrological stations over the period 1935-2010. An empirical orthogonal function analysis (EOFs) was employed to characterize the spatial variability of winter streamflow. The dominant mode captures in-phase variability of river flow anomalies over the entire country. The second mode is characterized by a north-south dipole, emphasizing the influence of topography over the streamflow variability. Both modes are related with large-scale atmospheric circulation and sea surface temperature patterns. We show that the Arctic/North Atlantic Oscillation, East Atlantic, East Atlantic/Western Russia and Scandinavian patterns control a significant part of the interannual winter streamflow variability as captured by these two modes. Moreover, we show that the winter streamflow is very sensitive to the influence of winter temperatures. Positive streamflow anomalies are recorded during warm winters, which are favorable to precipitation fallen as rain, while cold winters can favor snowy winters and frozen ground and hence reduced winter discharges. © 2014 Elsevier B.V.


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


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.


Ionita M.,Alfred Wegener Institute for Polar and Marine Research | Lohmann G.,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
Journal of Hydrometeorology | Year: 2012

Interannual-to-decadal variability of Rhine River streamflow and their relationship with large-scale climate anomaly patterns for spring [March-May (MAM)] and autumn [September-November (SON)] are investigated through a statistical analysis of observed streamflow data and global climate anomaly fields. A wavelet analysis reveals that spring streamflow variability is nonstationary with enhanced variability in the 8-16-yr band from 1860 to 1900 and in the 2-8 and 16-30 yr after 1960. A composite analysis reveals that streamflow anomalies during spring are related to a sea surface temperature (SST) pattern that resembles the corresponding El Niño-Southern Oscillation (ENSO) SST pattern. The corresponding atmospheric circulation pattern favors enhanced moisture advection over the Rhine catchment area during positive streamflow anomalies. During autumn, the streamflow variability follows a distribution similar to spring streamflow, but with a strong peak in the 30-60-yr band. Autumn streamflow anomalies are significantly related only with the North Atlantic SST anomalies. The atmospheric circulation pattern associated with high streamflow during autumn, which is more regional than the corresponding spring pattern, shows a deep low pressure system over the British Isles and the northwestern part of Europe and a shift southward of the Atlantic jet axis. The orientation of the axis of the Atlantic and African jets, as well as the advection of the moist air from the ocean, plays a crucial role in the variability of Rhine streamflow both in spring and autumn. © 2012 American Meteorological Society.


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.


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.


Mic R.-P.,National Institute of Hydrology and Water Management | Corbus C.,National Institute of Hydrology and Water Management | Matreata M.,National Institute of Hydrology and Water Management
Carpathian Journal of Earth and Environmental Sciences | Year: 2015

The paper presents the preparation of the Romanian hydrological software CONSUL for long term hydrological simulation needs for assessment of climate change impact in extreme events. CONSUL model is a conceptual model based on semi-distributed parameters depending on the physical characteristics of the river basin. According to the schematic representation (physiographic modelling) of how water flows and collects in a river basin the model computes the discharge hydrographs on sub-basins and then performs their routing and composition on the main river and tributaries. The initial values of the model parameters corresponding to some of the model structures was estimated by the generalized relationships of those parameters in function of the morphometric characteristics of the river basin or of the river reaches. These relationships on obtain on the basis of the recorded data at the hydrometric stations using the major rainfall-runoff events. CONSUL model was calibrated (i) individual (based on the 25 rainfall-runoff events) for the simulation of the largest floods occurred during the period 1975-2010 in the Bârlad River Basin, Romania and (ii) globally, by continuous flow simulation from the period 1984-1988. Using the calibrated parameters the model validation was made also by flow simulation (at 6 hours time step) during the years 2006 and 2010. Average precipitation and air temperature (hydrological model input data) for each sub-basin was performed using a pre-processing program of meteorological data from original rectangular grid nodes corresponding to Bârlad River Basin, averaging being achieved as weighted values based on the representativeness of these nodes for each analyzed sub-basin. The flow simulation results with the CONSUL model in the Bârlad River Basin, during both the calibration and validation periods, showed that the model is robust and can been applied successfully for long-term flow simulation in modified climate conditions.


Minea G.,National Institute of Hydrology and Water Management
Central European Journal of Geosciences | Year: 2013

The purpose of this paper is to identify areas with high flash-flood potential based on an evaluation of physiographic factors controlling the formation of surface runoff. The research method relies on the use of the Flash Flood Potential Index (FFPI), which incorporates physiographic characteristics from the catchment (terrain slope, profile curvature, land use and soil texture). The spatial distribution of the physiographic factors (which contribute to the creation, control and concentration within the drainage network of the overland flow) and the classified zoning of areas according to their hydrological response were achieved with GIS techniques. The results obtained show that physiographic factors on 227 sq km (29%) favor surface runoff on slopes and its localization towards the drainage network. Notably, the highest values of FFPI belong to the lower part of the catchment, where high human population density can be found, reflecting an increased vulnerability to floods and inundations of this area. © Versita Sp. z o.o.

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