Rainfall extremes can cause a significant loss of lives and economic losses in Nigeria. This study aims to investigate the trends of summer rainfall extremes over Nigeria with daily station datasets from 1975 to 2013. Using the rainfall extreme indices recommended by the Expert Team on Climate Change Detection Monitoring Indices (ETCCDMI), it is found that regionally averaged summer total wet-day rainfall amount (PRCPTOT), maximum consecutive 5-day rainfall amount (RX5day), and wet-day rainfall intensity (SDII) have increased in the three climatic regions of Nigeria namely Guinea coast, Sub-Sahel, and the Sahel regions. Meanwhile, heavy rainfall days (R20mm) increased significantly over the Guinea coast and sub-Sahel regions, while the wet-day frequency (RR1) only increased slightly. The increase in PRCPTOT over the two regions is mainly resulting from the increasing intensity and frequency of rainfall extremes. However, the Nigerian Sahel is characterized by a decreasing wet-day frequency, which demonstrates that a large proportion of the increasing PRCPTOT in the region is more associated with intense rainfall than its frequency. These characteristic increasing trends of rainfall extremes may explain the frequent flood events over Nigeria and as such this study may give guidance to stakeholders on how best to cope with it in the future.

中文翻译：

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近十年来尼日利亚夏季极端降雨的加剧

极端降雨可能在尼日利亚造成严重的生命损失和经济损失。这项研究旨在利用1975年至2013年的每日气象站数据来调查尼日利亚夏季极端降水的趋势。使用气候变化检测监测指数专家组（ETCCDMI）建议的极端降雨指数，发现该地区的夏季平均水平尼日利亚的三个气候区，即几内亚海岸，萨赫勒地区和萨赫勒地区，湿日降雨量（PRCPTOT），连续5天最大连续降雨量（RX5day）和湿日降雨量强度（SDII）有所增加。 。同时，几内亚沿海和萨赫勒以南地区的强降雨日（R20mm）显着增加，而湿日频率（RR1）仅略有增加。在两个地区，PRCPTOT的增加主要是由于极端降雨的强度和频率增加。但是，尼日利亚萨赫勒地区的特征是湿天频率下降，这表明该地区PRCPPTOT上升的大部分与强降雨有关，而不是频率更高。这些极端降雨的特征性增长趋势可以解释尼日利亚境内频繁发生的洪灾事件，因此，本研究可以为利益相关者提供指导，以指导他们将来如何最好地应对。