التذبذب المطري في محطة شحات: تحليل التباين والانحراف المعياري للهطول المطري وعلاقته بالظروف المناخية الموسمية (2024–1981)

Abstract

The study aims to investigate rainfall variability at Shahat Station during the period 1981–2024 using monthly rainfall data and annual total rainfall, linked to climatic factors such as humidity and temperature. The results revealed a clear annual rainfall fluctuation, with an average annual precipitation of 9.1 mm, a maximum of 21.2 mm in 2023, and a minimum of 3.5 mm in 2004. The years 2023, 2020, and 2019 recorded the highest positive deviations (+12.1, +8.7, and +4.5 mm), while 2004, 1999, and 2014 had the largest negative deviations (−5.6, −4.4, and −3.9 mm). Monthly analysis showed the highest standard deviations in December (1.79 mm) and January (1.66 mm), whereas July and August had the lowest values, around 0.7 mm. Rainfall is concentrated in winter and autumn, while summer is nearly dry despite high relative humidity (73–74%) and high temperatures (25–26°C). The findings highlight the importance of considering rainfall variability in water resource management and agricultural planning.