Frequency and Distribution Patterns of Maximum Consecutive Dry and Wet Spell in North Western Nigeria

Abstract

This study analyses the frequency and distribution pattern of maximum consecutive dry and
wet spells in Northwestern Nigeria during the growing season from June to September, using
the Anderson-Darling Normality Test. Daily rainfall data were sourced from the archives of
the Nigerian Meteorological Agency, Abuja, covering the period from 1980 to 2021. The
frequency of the Maximum Consecutive Dry Days (MCDD) and Maximum Consecutive Wet
Days (MCWD) was calculated using a frequency programme in Microsoft Excel. The results
showed that maximum consecutive dry periods ranged from 4 to 7 days, while maximum
consecutive wet days ranged from 1 to 5 days. Irregular distribution patterns of wet and dry
spells were observed across all states, except in Katsina, where results indicated a uniform
distribution pattern, with a P-value of -0.049 for dry spells in July. Information regarding the
distribution pattern of maximum consecutive dry and wet spell lengths needs to be well
understood at the grassroots levels to avoid the risk of drought and flooding and ensure food
security.