Assessment of the Impact of Climate Change on Rainfall Patterns in the Gaza Strip

Ecosystems, infrastructure, and society at all scales feel the effects of climate change and extreme climate events that have been documented all over the world. This research looked at daily precipitation data from eight meteorological stations in the Gaza Strip for a total of 49 years (1973-2021) to determine if there had been any significant changes in the spatial and temporal events of extreme precipitation. Eleven Extreme Precipitation Indices (EPIs) were developed by the Expert Team on Climate Change Detection and Indices (ETCCDI) to characterize the intensity, frequency, and duration of daily rainfall, and these are used to describe the extreme precipitation events. The eleven EPIs had their values estimated using RClimDex software, and their trends were analyzed using the Mann-Kendall test by RStudio software. All indices (with the exception of Consecutive Dry Days (CDD) index) showed rising trends. Just Consecutive Wet Days (CWD) index passed on average the significance test, and passed the significance test in 50% of meteorological stations in the Gaza Strip. The increase in CWD index suggests a potential rise in the length of the rainy season, the increase in water quantities, the mitigation of the demand for water resources, and the mitigation of pressure on the aquifer of the Gaza Strip. Five of these indices passed the significance test in one meteorological station, it includes: Total wet-day precipitation (PRCPTOT), Max1-day precipitation (RX1day), Max5-day precipitation (RX5day), Very wet-day precipitation (R95p) and Number of wet days (R1mm). These indices beside Extremely wet-day precipitation (R99P), Number of heavy precipitation days (R10mm) and number of very heavy precipitation days (R20mm) describe the magnitude in intensity and frequency of extreme precipitation occurrences, and the upward trend of these indices in all meteorological stations suggests the possibility of the potential of flooding, soil erosion and landslides in the Gaza Strip. This study found a declining trend in the CDD index, a measure of drought. A shorter summer (drought) season may be in the horizon for the Gaza Strip if CDD continues to fall as predicted. Vegetation loss may result from a combination of lower CDD, higher CWD, and higher PRCPTOT. Despite being separated by only a few kilometers, some meteorological stations in the Gaza Strip showed contrasting trends, especially in R1mm and CDD indices. Further, at the 99% confidence level, all EPIs (with the exception of the CDD index) have positive correlations with PRCPTOT. On the other hand, CDD has negative correlation with all EPIs).