Lake Sediment Geochemical Changes in Response to Land Use Variations in the Catchments of Lakes Volvi and Koronia, Northern Greece

摘要

Lakes Koronia and Volvi, located within the Mygdonia Basin in northern Greece, comprise an internationally protected wetland. The lakes support major industrial and agricultural activities, and a population of 45,000. Consequently, both sites have been greatly impacted by the conversion of marshland to farmland, water losses to irrigation, and pollution discharges including raw sewage, agricultural run-off, and industrial wastes. Sediment chronology and accumulation rates have been determined in cores from multiple sites within the lakes using 210Pb dating techniques. Bulk sediment elemental composition (organic carbon content, C/N ratios, etc.) and trace metal concentrations have been measured to provide critical evidence for variations in land-use within watersheds. Stratigraphic variations in the carbon and nitrogen isotopic ratio of sedimented organic matter have been measured to determine changes in aquatic ecosystem productivity. The geochemical results will be compared to historical records to determine the relative importance of disturbances caused by urban, agricultural, and industrial activities.