Hydrological climate change impact analysis for the Figeh spring near Damascus, Syria

摘要

Aset of downscaled climate change data from transient experiments with regional climate models has been used to access the future climate change signal in the area of the Figeh spring system in Syria and its potential effects on future water availability. The data ensemble at a spatial resolution of 0.258 has been investigated for the period 1961-90 for present-day climate and the periods 2021-50 and 2070-99 for future climate. The focus is on changes to annual, seasonal, and monthly surface air temperature and precipitation. For the first time, the Figeh spring discharge has been assessed with a hydrological runoff model based on an artificial neural network (ANN) approach. The ANN model was formulated and validated for the years 1987-2007, applying daily meteorological driving data. The investigations show that water supply from the spring might face serious problems under changed climate conditions. An expected, a precipitation decrease of about 211% in winter and 28% in spring, together with increased temperatures of up to 11.68C and a significant decrease in snow mass, can substantially limit the water recharge potential already in the near future until 2050. In the period 2070-99, the annual precipitation amount is simulated to decrease by 222% and the annual mean temperature to increase by 148C, relative to the 1961-90 mean. The ensemble mean of the relative change in mean discharge reveals a decrease during the peak flow from March to May, with values up to 220% in 2021-50 and almost 250% in the period 2069-98, both related to the 1961-90 mean.