CORRELATION OF THE RELIEF CONDITIONS, HYDROGRAPHIC NETWORK FEATURES AND HUMAN INTERVENTIONS WITHIN THE BLAHNIŢA RIVER BASIN (SOUTHWESTERN ROMANIA)

Abstract

Significance of rivers within plains is increasing nowadays as hydrographic network has become one of the most important strategic axes. The objective of the present study is to highlight the evolution of the Blahniţa River and the adjacent hydrographic network (in relation to the hydrostatic level of the groundwater aquifer) in the context of current modeling (natural and anthropogenic) of the entire river basin. The results are a step forward towards understanding the degree of anthropogenic transformation of a hydrographic network. The digital data obtained from the analysis of the cartographic documents contributed to the identification of hydrographic network along the considered period (1978-2020) with the presentation on four stages of the evolution under the anthropogenic interventions such as: construction of the irrigation system, drainage of the ponds, regularization and earth dams along the Blahnița River and channalization of the Blahniţa course. The geomorphological analysis of the relief conditions was based on the study of the hypsometry variation at the level of the entire hydrographic basin, especially along the watercourse. In this sense, the results highlight the importance of slope for surface flowing: the slope of the Blahniţa river basin presents values of 4 to 2o/oo to the confluence with Orevița and values from 1.8 to 0.06o/oo to the exit from the plain to the Danube Floodplain. The importance of this research consists in rising a red flag on former wetlands that have been dried up, which are currently undervalued and which may be true ecosystems for sustaining habitats in the future.