Volume XIII |

Preliminary data on the Jiu River meanders in the lower course (South-West Romania)

Abstract: The aim of this study is the complex monitoring of the Jiu river bed in terms of geometry and complexity of meanders in its lower sector (on a length of 77 km). The detailed analysis of the lower Jiu sector meanders completes the geomorphologic knowledge of rivers in Romania, starting from the identification and determination of the type of meanders: the results that were achieved are represented by the indexes concerning their age and migration rate (wavelength, 1977 – 4721 m; meanders amplitude, 511 – 2862 m; the mean radius of curvature, 270 – 997 m and the sinuosity index, from 0.87 to 2.17). Another aim of this study is the identification of the evolution features of the Jiu river, the relationships between some hydrological factors of control (liquid flow and suspended sediments – annual average values) and the generations of meanders (actual or open meanders, and incised meanders or paleomeanders) distributed in two sectors: Podari – Padea sector and the sector stretching from Padea up to the Danube confluence. In addition, our concern is motivated by the fact that in the last years there were analyzed the landslides and subsidence on the right slope of the Jiu river (next to Bâzdâna and Drănic settlements), strongly eroded and in close connection with the meandering of the watercourse.

Volume XI |

Land use changes in the Bâsca Chiojdului river basin and the assessment of their environmental impact

Abstract: The paper aims at analyzing the environmental quality of the Bâsca Chiojdului river basin by calculating a variety of environmental indices: human pressure index through population dynamics, human pressure index through agricultural land use, the naturality index, artificialization index and environmental change index. Choosing a 1 km grid for calculating and comparing these indices at the level of the river basin allows a more concise analysis on the environmental quality. Subsequently, the temporal dynamics of the environmental indices values is highlighted by the 40 years interval used especially in the human factor analysis, and by choosing the year 2005 as reference year. The results, embodied in the values obtained by applying formulas to calculate the environmental indices (human pressure index through agricultural land use – 44.19% agricultural land, the naturality index of the landscape – 50.82%; the artificialization index of the landscape – 2.32%; the environmental change index: Maruszczak version – 33.92; the improved version – 1.09, the completed version – 10.83) present the state of the environment. The proposed measures to stabilize and maintain a good environmental quality in the Bâsca Chiojdului river basin regard mainly the forest ecosystem, because it is the most important factor of maintaining the balance by its protective functionality on the environment.

Volume X |

Indicators of the Human Pressure on the Environment in the Bălăciţa Piedmont

Abstract: The Bălăciţa Piedmont represents the western subdivision of the Getic Piedmont, being located in south-western Romania. The unit under study is an early inhabited space and, at the same time, an area of active development of numerous geodynamic phenomena. The man-induced changes had significant influences upon the environment and especially upon the relief, the increased vulnerability of the terrains to the dangerous geomorphologic phenomena being one of the most important problems that the local communities have to face nowadays. The present study aims to assess the human influence upon the emergence of environmental unbalances and especially the human actions that influence the risk geomorphologic processes. A relevant means in the process of evaluating the type and dimension of the human intervention within a given territorial unit concerns the computation of certain synthetic indicators that characterize the degree of landscape transformation. The assessment has been realized through the analysis of statistical data at the level of the administrative-territorial units that overlap the Bălăciţa Piedmont. The general research regards an interval of thirty years (1977 – 2007), while the focus was laid upon the transition period (1992, 2002, and 2007).

Volume X |

Ecological Status Assessment of the Water Bodies Located in the Lower Sectors of the Jiu and the Motru Rivers (Oltenia, Romania)

Abstract: By means of the Water Framework Directive methodology, the present study identifies the valid indicators used for evaluating the ecological status of two natural water bodies (the first located on the Jiu river between Bratovoieşti and the Danube confluence, and the second on the Motru river between the Jirov and the Jiu confluence): hydromorphological indicators, physico-chemical indicators and biological indicators. The quality parameters deviated from the norm are: Shannon-Wiener Diversity Index – 2.87 for the Motru WB and Functional groups index – 0.68 for the Jiu WB (biological Indicators); modified water-cross section coefficient (depth) (1.22) – the Motru WB, impoundment coefficient (0.91) – the Motru WB and Coefficient of major streambed reduction (1.24) – the Jiu WB (hydromorphological indicators). The quality parameters (physico-chemical indicators) of the water drainage systems deviated from the norm are: Biochemical Oxygen demand BOD5 (40.78 mg/l) and Ammonium Nitrogen N-NH4 + (6.96 mg N/l) for Strehaia settlement; Biochemical Oxygen demand BOD5 (33.70 mg/l), Ammonium Nitrogen N-NH4 + (19.66 mg N/l) and Total Phosphorus PT (8.96 mg/l) for Craiova settlement. The target is to validate the ecological status for the two water bodies, respectively „moderate status” for the lower Jiu and „good status” for the lower Motru, related to the Class II and Class III of the European process of intercalibration, ensuring thus the compatibility at European level. The relevance of the paper consists in the assessment of the ecological status of two natural water bodies located downstream with respect to a major punctiform polluting source (two major settlements, Craiova on the Jiu, respectively Strehaia on the Motru), impacting heavily the achievement of environmental objectives set by the Water Frame Directive.

Volume IX |

The Analysis of the Relief Fragmentation Features within the Bălăciţa Piedmont

Abstract: Within the Bălăciţa Piedmont there are to be distinguished two areas with specific features, which correspond to the Danube catchment and to the Jiu drainage area. Both in the case of the drainage density, as well as in that of the relief energy, the distribution of the value classes correlated with the two catchments underlines major differences, but also certain resemblances, situation which is explained by the evolution time, the base level, the flow direction in relation with the structure and the lithological and climatic homogeneity.
The analysis of the data enabled the quantification of the relief energy and of the drainage density within the Bălăciţa Piedmont, as well as the correlation of the two parameters in report to the main catchments. The computation and representation methods for the two indicators of the relief fragmentation (i.e. the depth and the density) allowed for a quantitative interpretation (the identification of five value classes), as well as for a spatial interpretation (the grouping of the values depending on the two collecting rivers: the Danube and the Jiu). The aggregation of the influence factors on the two main drainage areas is mostly due to the fact that the Danube catchment extended its area in the detriment of the Jiu catchment, the three more important tributaries (the Blahniţa, the Drincea and the Desnăţui) catching sectors within the upper course of the tributaries of the Jiu.
The analysis of the relief fragmentation within the Bălăciţa Piedmont shows that this unit is on different evolution stages. The complexity of the fragmentation is closely connected to the maturity degree of the valleys and to the morphogenetic complexes imposed by the paleogeographical evolution.