Rainfall Trend Analysis and IDF Curve Generation for Bujumbura Mairie in East Africa

Abstract

This study aimed to analyse rainfall trends and IDF curve generation for Bujumbura Mairie using historical data for the past 30 years. In this study, the procedures adopted consisted of the statistical analysis of daily rainfall, rainfall anomaly, rainfall regression, Mann Kendall test, Sen’s slope, and return period using: Gumbel Method, long Pearson method,log-normal method, and Normal method. To do so, rainfall data from 1991-2020 was employed. The data that we collected was analysed using SPSS software. Result showed that there were 88.97 non-rainfall days’ means in the long-wet season FMAM (Feb, Mar, April, and May) and 294.67 non-rainfall days mean in 30 years from 1991 and 2020. After analysis, the excess rain years observed were 2020 for both the annual and long-wet seasons. Fourth deficit rain years (1994, 2005, 2006, and 2018) were observed for annual and long wet-season analysis. To quantify the possible effects of climate change and adapting to them is an important way of reducing vulnerability to them.The relationship between the IDF curves that is determined in this study is intended to use statistical analysis of the rainfall data observed for the past 30-year record.