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Assessing the Someşan Plateau water supply.
pp: 9-24 | DOI: 10.24193/RCJ2023_5  | Full text

The sustainable development of the Someşean Plateau, a water-deficient region, requires solving the problem of ensuring the water supply for the population and agriculture. In this sense, in the present study, were analyzed a series of aspects related to: water supply sources (auththous and allochthous) of the localities; the amount of water distributed to consumers from the main subunits of the Someşean Plateau. Special attention was given to the evaluation of water needs (in four variants) at the level of localities, counties, hydrographic basins and geographical subdivisions. Finally, the optimization of water supply solutions for the localities in the studied region was analyzed.

The role of the relief in the process of water drainage of the rivers in the Căliman Mountains.

pp: 25-36 |  DOI: 10.24193/RCJ2023_7  | Full text

The analysis of the flow of river water from a certain surface is very important f r determining the multi-year flow regime. In the formation of the regime, an important role is played by the features of the relief of the hydrographic basin, which directly influence the direction of flow and the speed of the water, and indirectly, the climatic elements. The Căliman Mountains are less analysed from this point of view, the relief elements being included in only a few specialized works. In the study, the role of the morphometric elements (altitude, geodeclivity, density and depth of fragmentation, orientation of the slopes) and morphological elements of the relief in the flow process from the highest volcanic massif in Romania located in the central part of the Eastern Carpathians was analysed.

An Evaluation of Lidar, EU-DEM and SRTM-Derived Terrain Parameters for Hydrologic Applications in Țibleș and Rodnei Mountains (Romania)
pp: 39-58 |  DOI: 10.24193/RCJ2023_1   | Full text

Over the years numerous geospatial data sets have become accessible to users in the form of various types of digital elevation models (DEMs) at different resolutions. DEMs are often used to study the behavior and hydrological response of watersheds, and so came to be considered as a reflection of their physiographic characteristics. Accurate determination of a catchment's morphometric parameters plays a crucial role in distributed hydrological modelling and river flow estimation. This study is divided into two parts and objectives; the first part examines the accuracy of DEMs from different sources (EU-DEM, SRTM and LIDAR) in deriving terrain attributes by comparison, and the second one investigates the ability of resampling the 3 m LIDAR DEM to coarser cell resolutions, to accurately represent the extracted hydrological features. In order to evaluate the quality and precision of SRTM and EU-DEM, the high-resolution 3 m LIDAR DEM was used as a reference data set due to its higher degree of accuracy. Firstly, this data set was resampled to 25 m and 30 m to match the EU-DEM and SRTM cell size, and all of them were re-projected in order to have the same Stereo 70 coordinate system for Romania. A comparison has been carried out between the derived hydrologic and terrain variables of the different DEMs. For the second part of this research, LIDAR DEM was also resampled to 10 m and subsequently, another similar evaluation was made, but this time with regards to different cell resolutions (3 m, 10 m, 25 m and 30 m). Several catchments of various drainage areas (Țibleș, Runc, Sălăuța and Valea Caselor) located in Țibleș and Rodnei Mountains were chosen as study areas for this research. Several resampling techniques available in ArcMap were evaluated, and the comparative analyzes were carried out using the R software. Results revealed not only the LiDAR's superior accuracy as compared to the other data sets, but also the possibilities offered by the latter for deriving the hydrological characteristics of a mountainous area, contingent upon what the user aims to achieve.

The effects induced by the appearance of periods with maximum flow on rivers in the Suceava hydrographic basin
pp: 59-68 |  DOI: 10.24193/RCJ2023_4  | Full text

Floods represent the hydrological hazard that occurs most often around the world and along the human and Earth’s history. Floods affect the natural and anthropic environment, and have positive (nutrients transport, regeneration of underground water resources and ecosystems, etc.) and negative effects. Suceava River basin is an area belonging to the Eastern Romanian Carpathians and Moldavian Plateau that is not that often affected by the negative effects of the maximum water flow, which are the floods. This article tries to present the periods when the floods had negative effects of the studied area. In the interval 1950-2010 where periods when floods were not recorded, but also periods when the negative effects were so evident, that it generated loses of human lives, damages to households and infrastructure, etc.. The most important period with floods was 2005-2010, when the effects were disastrous to the natural and human environment, summing thousands of lei in monetary value.

Analysis of floods in the Cotmeana catchment based on statistical and geographic information systems (G.I.S.) methods
pp: 69-85 |  DOI: 10.24193/RCJ2023_6  | Full text

Knowing the characteristics of floods, as well as the risk areas where they can occur, is nowadays of a major importance for the management of watersheds most affected by water-related hazards. This study aims, on the one hand, to analyze the floods produced in the last 5 decades on the Cotmeana river, and on the other hand, to map the zones where the flash floods can occur in the Cotmeana catchment. The Cotmeana River is located in the central-southern part of Romania, being a tributary of the Vedea River. It has a length of 93 km and a basin area of 495 km². The study is based on statistical processing of the hydrological data series from Ciobani hydrometric station on Cotmeana river from 1964 to 2014. The data was provided by the Argeș-Vedea Water Basin Administration (WBA), which includes annual and monthly data of the maximum discharge, as well as hourly discharge series of selected flood events. The floods were analyzed based on their hydrographs and with the help of statistical processing, the return periods of the maximum flows corresponding to the annual floods were calculated. In ArcGisPro environment, the areas susceptible to flash floods were identified and spatialized with the help of a slightly modified version of the Flash Flood Potential Index (FFPI). This index integrates a series of physical-geographic parameters such as slope, lithology, land use, soil texture, density of the hydrographic network, LS factor, etc., thus allowing the determination of the areas with the greatest susceptibility in terms of the production of flash floods. Apart from the morphographic parameters, frequently used in previous studies, in this study, two important factors in the genesis of floods were included in the calculation of the FFPI: rainfall and snow depth, resulting in a higher susceptibility in the north of the basin.

Variability of Air Temperature During Winter Between 1961-2022 in Southwest Romania (Oltenia)
pp: 89-105 |  DOI: 10.24193/RCJ2023_3  | Full text

The periods of heating and cooling of the weather on Earth followed each other with great irregularity and caused significant variations in air temperature but allowed the existence of life and especially of the human species. In the paper I have analysed the variation of the air temperature in Oltenia during the winters for the interval 1961-2022. A number of our other works have analysed climate variability in this part of Romania. After the warm interval 1945-1955 there followed a gradual cooling of the weather, and in the interval 1986-2022 (for 36 years), there was not a single very cold winter (FR) but only two cold winters (R) and two cool (RC). The interval 2000-2022 (23 years) was the warmest of the entire period of meteorological observations in Oltenia. Many annual, monthly and daily temperature climate records have been broken. At the same time, in the analysed interval, in the polar areas the rate of melting of the ice increased a lot and exceptional thermal maxima were recorded in the cold season. The warm periods during the winters were increasingly longer, more frequent and more intense. The work is useful to all those interested in climate variability in Oltenia.

The correlations between land use and landslides in the Territorial Administrative Unit of Mintiu Gherlii
pp: 108-115 |  DOI: 10.24193/RCJ2023_2  | Full text

Landslides are among the most important geomorphological processes in the Transylvanian Basin, particularly affecting agricultural land and decreasing its value for producing specific agricultural products. The Someșan Plateau and the Transylvanian Plain are the morpho-structural units most affected by landslides, accounting for 3% to 10% or more of the territorial and administrative divisions in the Transylvanian Basin, including Mintiu Gherlii. In this context, where geology and landforms are relatively consistent, land use is the primary factor that can produce changes. Our analysis indicates that arable land and pastures have the largest areas affected by landslides, and this suggests that the agro-techniques used so far may not have been the most suitable. Therefore, preventive and control measures should be implemented to reduce the surface areas affected by landslides and minimize their impact on the local economy.

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