Using ensemble of climate models to evaluate future water and solutes budgets in Lake Kinneret, Israel

SummaryIdentifying and quantifying future climate effects on water resources has major economic and societal implications, rendering such studies extremely important for water planners. Here we integrate output from one high resolution global (Japan Meteorological Agency) and three regional (ECHAM-RegCM, Hadley-MM5, ECHAM-MM5) climate models into three hydrological tools (1. annual incoming water volumes; 2. evaporation from the lake; and 3. lake salinity) to provide first approximations of climate change impacts on water quantity and quality in Lake Kinneret (also known as Sea of Galilee), the major freshwater resource in Israel. Meteorological data extracted from the climate models were used as input data into the models. Results were calculated for the historical 1979–2009 and the future 2015–2060 periods. The modeled historical period was verified against observed data, first by each model alone, and then by the combined model structure. Predicted results varied between the climate models. The ECHAM-RegCM predicted decreased precipitation in an average rate of ∼7 mm year−1 (−0.8% annually) while the trends of precipitation predicted by the other models were less obvious. According to the combination of ECHAM-RegCM, ECHAM-MM5 and Hadley-MM5 with the lake evaporation model, the evaporation will increase by 0.2–0.6 Mm3 (0.10–0.25%) annually while according to the JMA no trend was found. The lake salinity is mostly impacted by changes in inflows and therefore only the ECHAM-RegCM predicted significant increase of salinity (from 280 ppm Cl today to ∼450 ppm Cl in 2060), while the trends of salinity according to other models were mild.

► Output from ensemble of four climate models were integrated into three hydrological models.
► Predictions of climate change impact on inflows, evaporation and salinity in Lake Kinneret, Israel.
► Ensemble integration prediction for water inflows (2015 -2060) is a reduction of ∼2.6 Mm3y-1.
► The expected trend of evaporation (2015 -2060) is an increase of ∼0.41 Mm3y-1.
► The expected trend of lake salinity (2015 -2060) is an increase of 1.18 mg Cl- L-1 y-1.