The Impact of Human Interventions and Changes in Climate on the Hydro-Chemical Composition of Techirghiol Lake (Romania)

The aim of this study is to establish the potential effect of changes in climate and anthropic interventions made over time on the hydro-chemical properties of the Techirghiol Lake. Located in the littoral region of the Black Sea, Techirghiol Lake is the most hypersaline lake of Romania—well-known for the therapeutic properties of the saline water and sapropelic mud. Long-term time series of salinity and water level were investigated in relation to the lake water inputs (precipitation, overland flow and groundwater), to chemical parameters (pH, DO and BOD5) and also to the hydraulic works designed and built in the region. The obtained results reveal a degradation of this ecosystem in the period of 1970–1998, when the extensive irrigation practice in the proximity of the lake had a negative effect on the water budget of Techirghiol Lake (an increased freshwater input through runoff and seepage), followed by a major decrease of the lake’s salinity.