Keyword: Oana IONUS

Types of evaluation used in extracurricular didactic-geographic activities

Elisabeta CIOCAN Oana IONUŞ
Abstract

Extracurricular didactic-geographic activities contribute to the enhancing and the evaluation of the knowledge assimilated by the students during class hours. During these activities, the students can directly observe the phenomena and processes in nature, not being forced to use substitutes of reality as learning tools. Through the practical exercises performed, teamwork, the student-student, teacher-student relationship are improved. Students rediscover the motivation to learn, get involved in decision-making, approach innovatively: learning, transferring theoretical knowledge in practical activities.

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Assessing flood magnitude and frequency. Case study: 2013 spring floods on the Jiu river, Filiași – Craiova sector (South-West Romania)

Oana IONUŞ  Mihaela DOBRE  Elisabeta CIOCAN
Abstract

The main objective of the study is to use the statistical models to analyse the probability of flood and the joint of temporal variability of the flood peaks and their seasonality. The case study refers to the 2013 spring floods on the Jiu River, Filiași-Craiova sector. Thus, in order to obtain several features of the maximum discharge, the maximum values, the increasing and decreasing time also the frequency of occurrence, one of largest floods is analysed. The data used were recorded at 3 hydrometrical stations on the Jiu River for a common period of 10 years.
The hydrological analysis is based on two methods of the maximum flow values: Mann-Kendal test and Gumbel distribution. In the first part, we have identified if it’s a trend or not in the data series of the annual maximum discharge using Mann-Kendall trend test and the results were obvious, both statistically and graphically. The annual trend at two hydrometrical stations is of decrease (Test Z values: -1.58, Filiași hydrometrical station and -0.81, Răcari hydrometrical station), while at the hydrometrical station that closes the analysed sector is an increasing trend (Test Z value: 0.62, Podari hydrometrical station).
The Gumbel distribution is used to process the data from a long observation period of the maximum values. Applying this method to the flood data registered at the three hydrometric stations along the Jiu river are corresponding certain return periods (years) as follows: 1,140 cm/s registered at Filiași hydrometrical station has a 15 years return period; 1,447 cm/s reached at Răcari hydrometrical station has a 24 years return period; 1,309 cm/s recorded at Podari hydrometrical station has a 27 years return period. The above-mentioned values confirm the magnitude of the maximum flow at Răcari and Podari hydrometrical stations and anticipate the potential damage.
The flood frequency analysis using statistical models is important and also required in Romania given that the statistics of extreme events plays an important role in the engineering practice of water resources management.

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Water quality index – assessment method of the Motru river water quality (Oltenia, Romania)

Oana IONUS

Abstract: The present paper aims at determining the water quality on the Motru river and at establishing its usage domains as water resource. The method consists in the computation of the Water Quality Index on the basis of the physical-chemical and biological quality parameters that were registered at the monitoring stations placed on the Motru river (Cloşani, Broşteni, and Faţa Motrului). This index was computed for a long time interval (2000 – 2009) and it specifies the appropriate usage category, but it can also reveal the changes occurred at the level of the aquatic ecosystem. The novelty brought to the flowing water quality management consists in the underlining of the value of this index as potential indicator of the ecological state of the rivers.

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The temporary lowering of water level from the phreatic of Jiu river meadow in the western area of Craiova municipality. Case study: West Gate Mall

Constantin ENACHE, Oana IONUŞ

Abstract: In order to carry out the foundation of WEST GATE MALL establishment, because the phreatic water level proved to be 1-2 m higher than the geotechnical study preestablished one, it was necessary its temporary lowering. For this problem to be solved we have suggested a double series of drillings with submersible pumps and between these foundations could be safely executed. Thus, according to our calculations presented in the article, the distance between the series of drillings has been established at 20 m, the dislevelment in the drillings reaching 4 m.

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Extreme hydrological phenomena in the hydrographical basin of the Danube. The floods from the spring of 2006 along the Oltenian sector of the river

Vasile PLENICEANU, Oana IONUŞ, Mihaela LICURICI

Abstract: Among the natural hazards that confront the human civilisation and its activities, floods represent hydro-meteorological phenomena with high frequency and with destructive effects, both in the economic and in the social sectors.
The Oltenian sector of the Danube Floodplain develops between Drobeta-Turnu Severin and Corabia, being 335 kilometres long and covering a surface of about 105 thousand hectares, which represents around 1/5 of the entire surface of the floodplain displayed by the Danube on the Romanian territory. Under the conditions of this geographical space, the Danube Floodplain presents high vulnerability.
It is necessary to explain the somewhat differentiated flooding of the Oltenian sector of the Danube Floodplain on the two sub-sectors: the one stretching between Drobeta-Turnu Severin and Golenţi – Calafat, as compared to the other, which extends downstream of Calafat, all the way to Corabia and Islaz. Also, it is important to show the reasons that led to the flooding of certain human settlements located within the southern sub-sector, on the morphological levels offered by the low and inferior terraces of the Danube, respectively the settlements that exist between Rast and the confluence between the Olt and the Danube rivers. Finally, taking into account the stipulations of the new National Strategy for Risk Management, we shall formulate certain recommendation to increase the resilience of the area to flood phenomena.

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Disparities in the water supply system – Waste water sewerage in Filiasi

Oana IONUŞ

Abstract. Presently, the water supply and sewerage works in Filiasi town are operated by AQUATERM Filiaşi. But, due to some disfunctions in this system of infrastructure, the management of water resources at the level of the town is deficient. This fact is due, on one hand, by the quality of underground waters which do not comply because of the increase of the ammonia content over the admissible limits, and, on the other hand, by the quality of underground water which have a high content of iron and sulphur as they are in direct contact with the coil layers. Hereupon, the potable water supply for Filiaşi town is performed directly from the adduction pipe from Izvarna. The present paper aims to identify the disfuctionalities inside the water management system (under-dimensioning – the degradation of the existing networks and the low capacity of the waste water treatment plant) and in the same time to offer solutions for a better operation, because by improving the infrastructure for the water supply system, for the sewerage networks and waste water treatment plant will determine the rise of the quality of the environment factors and the life standards.

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