The Impact of Climate Changes on The Climatic Water Balance in The Syrian Coast Region During the Period (1980 to 2020)

Objectives: This study aimed to investigate and analyze the impact of temporal changes in climatic elements (temperature, precipitation, relative humidity, solar radiation, wind, and reference evapotranspiration) on the climatic water balance in the Syrian coastal region from 1980 to 2020. This will be achieved by using statistical indicators and equations to elucidate the relationship between precipitation, reference evapotranspiration, and climate change indicators, utilizing five climate stations distributed in the region (Tartous, Safita, Latakia, Al-Kurdaha, and Slunfah). Methods: The study used the Mann-Kendall equation to verify the hypothesis of temporal temperature changes at the studied stations. The Climatic Water Deficit (CHD) was evaluated using monthly and annual climate data (temperature and relative humidity) to calculate reference evapotranspiration values at the stations based on the Ivanov equation. This represents the difference between precipitation (P) and reference evapotranspiration (ET0) calculated using the Penman-Monteith method, for the period from 1980 to 2020. Additionally, drought and surplus years were identified using the decadal method. Results: The study results showed a significant upward trend in reference evapotranspiration at all stations over the study period, with a water deficit observed at all stations except Slunfah. Analysis of the drought index revealed that precipitation was less than 30% of expected precipitation in 15 years during the study period. Conclusions: The general trend of rainfall in the Syrian coast was analyzed, along with the study of agricultural drought years and periods of water surplus based on decadal categories. Additionally, the study evaluated the climatic water balance during the period (1980-2020), shedding light on the variations and challenges faced due to natural factors and site characteristics.