To use the environmental isotopes for wetlands: a case study from Kucuk Menderes River Coastal Wetland, Selcuk, Izmir, Turkey

Environmental isotopes were used to identify the relationship between wetland and groundwater; and salinization processes, and to estimate the circulation time of the groundwater in the Selcuk Plain. The δ18O and δ2H compositions of wetland area samples range from -5.40 per mille to -2.93 per mille and from -35.1 per mille to -19.55 per mille, respectively. The lakes and rivers are plotted on the mixing lines with slopes of 5.8 and 5.5 because they belong to the open system in the hydrologic cycle and there is a salinization in the plain. To identify the dominant process, δ18O-Cl relationship was used. The river and the lake Kocagoz are plotted on the evaporation line. In addition, in rainy season the lake Akgol and in dry season the lake Gebekirse are plotted between evaporation and mixing line, which shows the effect the seawater on the lakes. In the light of the Tritium values, the groundwaters are recharges with modern rainfalls with 5-6 TU values and show the short circulation time of groundwaters. (author)