Spatiotemporal Analysis of Cold-Season Minimum Runoff in the Argeș-Vedea River Basin

Taking into account the different causes that generate the minimum flow during the warm season (May-October) and the cold season (November-April), as well as the fact that the use of minimum flow values in design activities is related to seasonal consumptions specific to each period, the study of minimum flows is generally carried out separately. In this paper we analyzed the minimum flow during the cold season (November-April) within the Argeș - Vedea hydrographic area, by utilizing the average minimum daily flows from the hydrometric stations considered characteristic, for a period of at least 15 years and a maximum of 30 years, from the time interval, 1991-2020. The vulnerability assessment of the resources offered by the hydrographic network of the Argeș - Vedea hydrographic area during the cold period represents an interesting analysis objective with certain practical value. The paper carries out a detailed analysis of the runoff regime in the Argeș – Vedea hydrographic area in order to identify the causes (natural: climate change, winter phenomena or anthropogenic: the influence of the complex system of hydrotechnical works with a role in quantitative management of water resources) that contribute to their occurrence and of the dry periods and characteristic years in terms of minimum runoff. To achieve the objective of the paper, in addition to the statistical processing of data series from the hydrometric stations analyzed within the Argeș – Vedea hydrographic area, GIS interpolation methods were also used. The spatial distribution of the values of the specific minimum annual and seasonal average flows is approximately similar. The values decrease with the altitude from north to south, with the highlighting of some islands in the eastern part of the hydrographic area at the confluence of the Argeș River with its main tributaries, Dâmbovița and Neajlov, and in the western part at the confluence of the Vedea and Călmățui rivers. By identifying the ʺ0ʺ values of the minimum average flows, the presence of winter phenomena was observed in too few cases. This fact leads to the conclusion that global warming is reflected in the minimum runoff on the rivers.