Data on the characteristics and modelling of precipitation intensity duration and frequency in southern Nigerian cities

The data characterized precipitation of six capital cities in Nigeria (which experience very high rainfall amounts annually), since the regular monitoring and modelling of precipitation characteristics is scarce in these areas. The precipitation data for each city was analyzed statistically, having extracted the maximum data for each year. Rainfall daily maxima for each city and year were obtained. Minimum, mean and median rainfall were also obtained. The number of days in each year and the total annual sum were as well featured.

Furthermore, different durations were obtained for the maximum rainfall data after arranging the maximum precipitation in descending order. The Gumbel probability position method was to obtain the frequency of each maximum precipitation in each city. Rainfall Intensity, Duration and Frequency curves and models were thereafter developed from the data as presented. Performances and goodness of fit tests were used to evaluate the developed models. Precipitation duration curves were also developed for each city studied and these are as well included in the dataset.

Results of analysis performed from the r-studio translated in tables as well as the r-codes used all included in this repository.

本数据集围绕尼日利亚六大首府城市的降水特征展开研究——这些城市年降雨量极高，而该区域内降水特征的常规监测与建模工作相对匮乏。研究对各城市的降水数据开展统计分析：首先提取各年份的极值降水数据，获取各城市逐年的日最大降雨量，同时得到逐年的最小降雨量、平均降雨量与降雨量中位数，此外还统计了各年份的降雨天数与年总降雨量。此外，将各城市的最大降水数据按降序排列后，提取得到不同降雨历时数据；采用耿贝尔（Gumbel）概率位置法计算各城市各极值降水事件的发生频率。基于上述数据，进而构建了降雨强度-历时-频率曲线及相关模型，并通过模型性能评价与拟合优度检验对所建模型进行评估。本研究还为所有调研城市构建了降水历时曲线，相关内容均已纳入本数据集。本数据集同时收录了基于RStudio完成的分析结果表格，以及本次研究所使用的全部R代码。