Time Series Analysis of the Physicochemical Parameters and Meteorological Factors in a Mediterranean Lagoon

Global water resources are currently under increasing pressures that lead to their quantitative and qualitative degradation. Humanly imposed modifications of the environment lead to the deterioration of the quality and availability of the water resources, especially of vulnerable coastal, karstic systems. Towards the better understanding of the karst operational mechanisms, time series analysis is often employed, especially in lack of other resources. Under this scope, daily and hourly time-series of physicochemical characteristics (temperature, dissolved oxygen and electrical conductivity) for the period 2011–2015 at an especially vulnerable coastal wetland (Koumoundourou Lake, Athens, Greece) were statistically processed and analysed, so as to investigate the response of the lagoon to the underwater recharging karst system and the driving biological processes. Based on the results, the physicochemical variables are largely controlled by the groundwater inflows or sea water intrusion and macrophytes affect dissolved oxygen fluctuations. Precipitation affects the system after 72–79 days, while meteorological variables affect significantly the water temperature and electrical conductivity of the lagoon. Biological processes and freshwater inflows rather than climate factors seems to affect dissolved oxygen concentrations.