Analysis of variation in trends in rainfall amounts in the Tripoli region for the period 1990-2023.

Abstract

     The research aims to analyze the trend of rainfall in the Tripoli region for a period of 33 years (1990-2023) based on monthly and annual data of rainfall amounts through the application of statistical coefficients represented by the binomial coefficient model and the (2-Sample T) test to test statistical hypotheses. The study reached many results, the most important of which was the presence of several dry and wet rain cycles of varying quantity and length from the general average, amounting to five rain cycles according to the binomial model, including three wet cycles and two dry cycles. The year with the most rain in its annual average was 2023 (655.23 mm), while the year with the least rain in its annual average was 2010 (165.00 mm), so the difference between them is (490 mm). The study also concluded that the trend of rainfall in the Tripoli region is going in one direction and the difference between the two averages is not large through the 2-Sample T test through the value (P. value), which is equal to (0.790) is greater than the significance level (a) 5%. I also accepted the null hypothesis, which is that the average rainfall of the first period and the rainfall of the second period for the Tripoli region is equal to zero, which is the value that falls within the confidence interval (-0.27) with a confidence level of 95%.