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Research about Romania

Source-linked reports with geographic coverage including Romania.

7 recordsLinked to original sources
USGS2025

Assessment of coastal and fluvial morphodynamic changes using Structure-for-Motion: A case study of the Sfȃntu Gheorghe Mouth (Danube Delta, Romania)

The ability to accurately map erosion, flooding, and habitat loss in coastal environments is crucial for formulating national strategies aimed at preventing and mitigating the impacts of natural disasters. A fundamental component of this process is the implementation of coastal morphodynamics monitoring through Structure-from-Motion (SfM) techniques, utilizing high-resolution 2D/3D data obtained from aerial photogrammetry. To assess morphodynamic changes over a three-year period (2022 – 2024), several SfM-based photogrammetric studies were conducted, each year, in the Romanian sector of the Danube-Black Sea coastal zone, specifically at the mouth of one of the Danube River distributaries (Sf Gheorghe branch) into the Black Sea, and along the left bank, near Sf Gheorghe locality, located within the Danube Delta Biosphere Reserve (DDBR). The essential equipment for aerial photogrammetry comprises Unmanned Aerial Vehicles (UAVs) and Global Navigation Satellite Systems (GNSS). In this study, the UAV used was a DJI Mavic 3T (Enterprise/Thermal) drone, complemented by two Trimble R12i and R4 GNSS systems, as well as approximately 10 Ground Control Points (GCPs). Data acquisition and processing were carried out using specialized photogrammetric software (Agisoft Metashape) along with various GIS tools (e.g., Blue Marble Geographics Global Mapper and ESRI ArcMap). The photogrammetric products generated for the study, as detailed in this paper, include Digital Elevation Models (DEMs), Digital Terrain Models (DTMs), orthomosaics (orthophotos), and others. At Sfântu Gheorghe beach, a comparison between 2023 and 2024 photogrammetric surveys revealed that the left bank of the Sf. Gheorghe Arm, at the river mouth into the Black Sea, suffered from a twist (erosion) of up to 64 metres. Additionally, on the selected perimetre (total area of 31,910 square meters ) from the beach and dune zone of Sf. Gheorghe, an area of up to 16,202 square meters was eroded between 2023 and 2024. This contrasts with the period between 2022 and 2023, during which deposition predominated. Erosion at the Danube mouths and the adjacent Black Sea coastline is driven by a complex interaction of natural and anthropogenic factors. Natural processes, including subsidence, sea-level rise, and episodic extreme storm events, contribute significantly to coastal dynamics. Meanwhile, human-induced factors, such as upstream hydrotechnical works that limits sediment transport, cutting of navigation canals, as well as the exacerbating effects of climate change, further accelerate erosion. The recent Structure-from-Motion (SfM) surveys provide essential quantitative data, enabling a detailed analysis of both short-term and long-term morphodynamic changes influenced by seasonal variations and extreme hydrometeorological events in this highly dynamic coastal system.

Sfȃntu Gheorghe Mouth (Danube Delta)↗
USGS2024

Thickness distributions and evolution of growth mechanisms of NH4-illite from the fossil hydrothermal system of Harghita Bai, Eastern Carpathians, Romania

The crystal growth of NH 4 -illite (NH 4 -I) from the hydrothermal system of Harghita Bãi (Eastern Carpathians) was deduced from the shapes of crystal thickness distributions (CTDs). The 4-illite-smectite (I-S) interstratified structures (R1, R2, and R3-type ordering) with a variable smectite-layer content. The NH 4 -I-S (40–5% S) structures were identified underground in a hydrothermal breccia structure, whereas the K-I/NH 4 -I mixtures were found at the deepest level sampled (−110 m). The percentage of smectite interlayers generally decreases with increasing depth in the deposit. This decrease in smectite content is related to the increase in degree of fracturing in the breccia structure and corresponds to a general increase in mean illite crystal thickness. In order to determine the thickness distributions of NH 4 -I crystals (fundamental illite particles) which make up the NH 4 -I-S interstratified structures and the NH 4, -I/K-I mixtures, 27 samples were saturated with Li + and aqueous solutions of PVP-10 to remove swelling and then were analyzed by X-ray diffraction. The profiles for the mean crystallite thickness (T mean ) and crystallite thickness distribution (CTD) of NH 4 -I crystallites were determined by the Bertaut-Warren-Averbach method using the MudMaster computer code. The T mean of NH 4 -I from NH 4 -I-S samples ranges from 3.4 to 7.8 nm. The T mean measured for the NH 4 -I/K-I mixture phase ranges from 7.8 nm to 11.7 nm (NH 4 -I) and from 12.1 to 24.7 nm (K-I). The CTD shapes of NH 4 -I fundamental particles are asymptotic and lognormal, whereas illites from NH 4 -I/K-I mixtures have bimodal shapes related to the presence of two lognormal-like CTDs corresponding to NH 4 -I and K-I. The crystal-growth mechanism for NH 4 -I samples was simulated using the Galoper code. Reaction pathways for NH 4 -I crystal nucleation and growth could be determined for each sample by plotting their CTD parameters on an α–β 2 diagram constructed using Galoper . This analysis shows that NH 4 -I crystals underwent simultaneous nucleation and growth, followed by surface-controlled growth without simultaneous nucleation.

Harghita Bai↗
USGS2011

International geophysics: Symposium on the hydrology of deltas

A Symposium on the Hydrology of Deltas was held in Bucharest, Romania, on May 6–9; it was followed by a field trip to the delta of the Danube River on May 10–14. The Symposium was organized by Unesco, with the collaboration of the Romanian Government and the support of the International Association of Scientific Hydrology (IASH). The Romanian Government did an excellent job of arranging for airport reception, hotels in Bucharest, a meeting hall for the technical sessions, hospitality sessions, a full side program for wives of delegates, and hotels, meals, and transportation (bus, train, and boat) on the field trip. The Institute of Hydrotechnical Research of the Romanian Government provided most of the support.

Bucharest↗
USGS2008

Initial sediment transport model of the mining-affected Aries River Basin, Romania

The Romanian government is interested in understanding the effects of existing and future mining activities on long-term dispersal, storage, and remobilization of sediment-associated metals. An initial Soil and Water Assessment Tool (SWAT) model was prepared using available data to evaluate hypothetical failure of the Valea Sesei tailings dam at the Rosia Poieni mine in the Aries River basin. Using the available data, the initial Aries River Basin SWAT model could not be manually calibrated to accurately reproduce monthly streamflow values observed at the Turda gage station. The poor simulation of the monthly streamflow is attributed to spatially limited soil and precipitation data, limited constraint information due to spatially and temporally limited streamflow measurements, and in ability to obtain optimal parameter values when using a manual calibration process. Suggestions to improve the Aries River basin sediment transport model include accounting for heterogeneity in model input, a two-tier nonlinear calibration strategy, and analysis of uncertainty in predictions.

Aries River Basin↗
USGS2008

Reconnaissance study of water quality in the mining-affected Aries River Basin, Romania

The Aries River basin of western Romania has been subject to mining activities as far back as Roman times. Present mining activities are associated with the extraction and processing of various metals including Au, Cu, Pb, and Zn. To understand the effects of these mining activities on the environment, this study focused on three objectives: (1) establish a baseline set of physical parameters, and water- and sediment-associated concentrations of metals in river-valley floors and floodplains; (2) establish a baseline set of physical and chemical measurements of pore water and sediment in tailings; and (3) provide training in sediment and water sampling to personnel in the National Agency for Mineral Resources and the Rosia Poieni Mine. This report summarizes basin findings of physical parameters and chemistry (sediment and water), and ancillary data collected during the low-flow synoptic sampling of May 2006.

Aries River Basin↗
USGS1977

Reconnaissance report of geotechnical observations for the 4 March 1977 Romanian earthquake

A catastrophic earthquake struck south central Romania at 21:21 hours (9:21 p.m.) local time, March 4, 1977. The tremor collapsed 33 multistory buildings in Bucharest and damaged many other structures to varying degrees. Important damage was inflicted on many other cities and villages, particularly Craiova and Zimnicea. (For locations, see Fig. 1) Over 1,500 deaths resulted from the shock. The epicenter of the shock was preliminarily located at 45.85° N, 26.73° E with a focal depth of 110 km. A preliminary magnitude of 7.2 was assigned to the event. Aftershocks up to approximately magnitude 4 have spread south westward from the epicenter (approximately as far south as Buzau). The focal depths of aftershocks in the southern part of the zone were shallower than the main shock (as shallow as 50 km). A team of nine United States scientists and engineers was sent by the U. S. State Department to make a reconnaissance investigation of earthquake effects and damage. The team consisted of; Charles Culver (team leader) and George Fattal, National Bureau of Standards; Gerald Bowles and Fred Ruud, Bureau of Reclamation; Ernest Dodson, Army Corps of Engineers; Ted Algermissen Chris Rojahn and Les Youd, U. S. Geological Survey; and Karl Steinbrugge, Insurance Services office and a consultant to U.S.G.S. Upon arrival in Romania, the team was divided into groups which generally specialized in the following areas: Culver and Fattal investigated structural damage to buildings. Algermissen and Steinbrugge investigated the general distribution of damage and types of buildings affected in Bucharest. Dodson, Bowles and Ruud investigated damage to dams and hydroelectric power plants. Rojahn collected strong motion records and initiated discussions with the Romanians on the possible development of additional strong motion seismographs. Youd investigated damage to foundations and occurrences of ground failure (landslides, etc.). The groups worked independently of each other. However, there was communication between groups during joint meetings with various Romanian officials and in the evening hours. The purposes of this report are: 1. To summarize geotechnical effects of the earthquake. 2. To outline and justify a proposed United States Romanian cooperative geotechnical program which was considered as part of a broader cooperative program in engineering and seismology. 3. To provide a log of my travels.

Open-File Report↗