EVALUATION OF THE SURFACE WATER QUALITY PARAMETERS OF THE SF. GHEORGHE BRANCH - DANUBE DELTA, ROMANIA

Generally, water quality involves the water�s physical-chemical and biological attributes that depend on the natural surrounding environment and anthropogenic impacts. Through the years, the river water quality in the Sf. Gheorghe Branch has been subjected to various hydro-sedimentary impacts, due to the anthropogenic meander cut-off plans initiated for navigational objectives. In this study, the Sf. Gheorghe Branch water quality evaluation was performed using in-situ observations, measurements, and datasets provided by EXO Water-Quality Sondes and Sensors, during May 2024, a period defined by the high-water levels of the Danube River. Thereby, surface water quality parameters. i.e., water temperature (oC), pH (unit.), dissolved oxygen (mg/L), dissolved oxygen saturation (%), chlorophyll �a� (�g/L), electrical conductivity (�S/cm), total dissolved solids (mg/L), salinity (psu), turbidity (NTU) and oxidation-reduction potential (mV) were evaluated immediately in-situ, at each site location. The results were plotted spatially as binary diagrams and corroborated with the national and international water reference standards to estimate the water quality status. The longitudinal distribution (along the upstream-downstream gradient) of the investigated water quality parameters along the entire Sf. Gheorghe River water (km 85 � km 15) has been identified as suitable for biodiversity, natural ecosystem assets, and ecological processes. In the context of high-water levels of the Danube River (May 2024), the obtained results complied with the imposed limits provided for the water quality criteria (Very Good and Good). The importance of this study may be considered as an approach to yield a basis for water quality assessment. Subsequently, these contributions may be used to water management strategies to overcome the insidious challenges to which the ecosystems of the Danube Delta are subjected.