The variability, intensity, and distribution of rainfall have drawn a lot of interest globally and especially in nations where rainfed agriculture is the norm. This article uses rainfall data from the Rwanda Meteorology Agency for the years 1981 to 2021 to delineate and analyze rainfall variability and trends in the Kayonza District. The time series were grouped using the K-means clustering technique based on computed Euclidean distance, the total within-cluster sum of squares, and the elbow plot technique to determine the optimal number of clusters. The coefficient of variation measures was employed to analyze rainfall variability, while Sen’s slope and the Mann–Kendall (MK) test were used, respectively, to find trends and changes in magnitude. The results indicated four near homogeneous zones named region one to four. The dry seasons indicated higher variability compared to rainy seasons and annual rainfall total with a variability of 128–142% over the southeastern part during June to August (JJA) season, while a variability of 16–48% was observed over most of the district during both annual and rainy seasons. It was further noted that the areas in the central part of the Kayonza District indicated a significant increasing trend at a significance level of 95% and above during January to February (JF), September to December (SOND), and on annual basis, while March to May (MAM) and JJA season exhibited no significant trend. The findings of this study are essential for creating adequate mitigation strategies to lessen climate change’s effects on agriculture as well as other socioeconomic sectors.

中文翻译：

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卢旺达东部卡永扎区降雨变化和趋势的时空分析，以改善气候风险管理

降雨的变化、强度和分布引起了全球的广泛关注，特别是在雨养农业为常态的国家。本文使用卢旺达气象局 1981 年至 2021 年的降雨数据来描绘和分析卡永扎地区的降雨变化和趋势。时间序列使用K进行分组-基于计算的欧几里得距离、簇内总平方和以及肘图技术的均值聚类技术来确定最佳簇数。采用变异系数测量来分析降雨变化，同时分别使用森斜率和曼-肯德尔 (MK) 检验来找出趋势和幅度变化。结果表明有四个接近均质的区域，称为区域一至区域四。与雨季和年降雨量总量相比，旱季的变异性更高，6 月至 8 月 (JJA) 季节期间，东南部地区的变异性为 128-142%，而大部分地区的变异性为 16-48%每年和雨季。进一步指出，卡永扎区中部地区在 1 月至 2 月（JF）、9 月至 12 月（SOND）以及每年期间均表现出显着增长趋势，显着性水平达到 95% 及以上，而3月至5月（MAM）和JJA季节没有表现出明显的趋势。这项研究的结果对于制定适当的缓解战略以减轻气候变化对农业以及其他社会经济部门的影响至关重要。