Change Trends of Annual Rainfall in Buraydah Area (Saudi Arabia) from 1982 to 2017: A Climate study

Abstract

This study relied on daily rainfall data observed during the period from January 1982 to December 2017 at six rain stations. The study’s methodology deals with the climate change aspects over Qassim area by analyzing the trends of change in annual rainfall and determining the best statistical method to predict it in the study area. On the other hand, the study aims to determine the annual rainfall trend in the stations most affected by the climate change effects during the studied period.

To achieve the objectives of the study, the methodology included analyzing rainfall trends by applying the moving averages, semi-averages, and the straight line regression methods. The statistical significance used the T-student test and the correlation coefficient at the 5% significance level.

The results of statistical tests showed that rainfall trends using the straight line regression method (linear correlation) were more accurate, as it takes the time variable when calculating the trend. It is also possible to test the regression and correlation coefficients using the “T-student” method, and then calculate the true regression coefficient value at the 95% probability level (2 S.Eb), and calculate the determination coefficient for the regression, the standard error of the estimate (S.E), and the percentage of standard deviation (%) σ). This study was able to determine the rainfall trends of annual rainfall and examine its statistical significance.