Hydrogeology of Lower Küçük Menderes river coastal wetland

Küçük Menderes River wetland is inside the Selçuk plain and identified with lakes, swamp and river. These lakes are recharged from precipitation and karstic springs that discharge from marble-schist and marble-alluvium contacts. According the perfect correlation between Na-Cl, Na-SO4 and Cl-SO4, it can be said that these ions are derived from seawater intrusion. Fe(OH)3 and MnHPO4 are oversaturated due to the high biological activities in the lakes. Major species of Se is selenite form due to its relation between Fe and organic matter in the wetland area. There are two different contamination risks for this wetland: (i) Selçuk waste disposal site and (ii) Selçuk treatment water plant where the purified waters release to the river. EC, Al, As, Cd, Cu, Fe and Zn values are very high according to aquatic life standards. Na/Cl and Cl/Br molar ratios of coastal zone that covers an alluvial aquifer, karstic discharges and full part of a wetland are the similar with seawater ratio. According to mixing ratios, seawater addition can be reached 9-8 percent and dry season at the coastal zone especially in karstic springs that are a kind of seawaterfreshwater mixing discharge points and it was proved by ionic ratios. Relationship between Cl and Br, B, Li, Sr gives a perfect correlation that explains the salinization process comes from marine intrusion. The O-18 and Deuterium composition of wetland area samples range between - 5.40 and -2.93, and -35.1 and -19.55, permil respectively. In the light of the Tritium values, the groundwaters recharge with modern rainfalls with 5-6 TU values and show the short circulation time of groundwaters.