Geospatial Analysis of Extreme Weather Events in Nigeria (1985–2015) Using Self-Organizing Maps

Table 1

Summary of rainfall indices used in the study (a wet day is defined as a day with at least 1 mm of precipitation).

Index	Descriptive name	Definition	Units
R1	Number of wet days	Frequency of rainy days	Days
R×1d	Maximum 1-day precipitation	Maximum 1-day precipitation	mm
SDII	Simple daily intensity index	Ratio between the total rain on wet days and the number of wet days	mm/day
R×5d	Maximum 5-day precipitation	Highest consecutive 5-day precipitation	mm