Modeling Climate Change Impacts at Ladik Lake (Turkey) Using SWAT.

This study aims to determine climate change impacts at Ladik Lake in Turkey using the Soil and Water Assessment Tool (SWAT). Ladik Lake is a natural lake and an ecologically important site located in the Yesilirmak River Basin in Turkey. In recent years, water level changes in the lake raised concerns regarding its future hydrologic and ecological characteristics. In this study, we used a basin-scale hydrological model, developed using SWAT, to simulate the sensitivity of Ladik Lake to climatic changes. RCP4.5 and RCP8.5 scenarios developed by MPI-ESM-MR, HadGEM2-ES, and GFDL-ESM2M Global Circulation Models outputs were used for representing future climatic conditions. These models were previously downscaled for Turkey by State Meteorology Service. Maximum and minimum temperature and precipitation projection data were added to the model for the 2021-2098 period. Annual reservoir volume data of 78 years from 2021 to 2098 period has been processed using Mann-Kendall Trend Analysis for the determination of trend (Z value) and slope (Q value) magnitude. The detected trends for the GFDL-ESM2M model were positive (upward) for RCP4.5 and negative (downward) for RCP8.5. While the rate of change in the RCP4.5 was 233 m3/year, this value was -77885 m3/year for the RCP8.5 scenario. The trends determined for the HadGEM2-ES model were negative for both the RCP4.5 and RCP8.5 scenarios. The decrease in RCP4.5 was -1111 m3/year, and the decrease in RCP8.5 was -1786 m3/year. For the MPI-ESMMR model, the detected trends were negative for both the RCP4.5 and RCP8.5 scenarios. The decrease in RCP4.5 was found to be -126620 m3/year, while the decrease in RCP8.5 was -273806 m3/year. Ladik Lake volume decreased in most of the models and scenarios, except for the GFDL-ESM2M model RCP4.5 scenario. These results suggest that Ladik Lake's water volumes are very sensitive to future climatic changes. [ABSTRACT FROM AUTHOR]