APPRAISAL OF METEOROLOGICAL FLOODS EVENTS OVER YOBE STATE, NORTHEAST, NIGERIA (1965-2015).

Abstract

This paper seeks to examine floods occurrence along with its frequency, duration, and magnitude
in Yobe State, Northeast, Nigeria for the period of fifty (50) years. Rainfall pattern was thoroughly
inspected in the light of trend so as to ascertain its effect on the occurrence of flood over the study
area. Scatter plot and its line of best fits and simple linear regression statistics were used to
understand the trend in the rainfall series. Standardize Precipitation Index (SPI) was employed
for the comprehensive quantification of three important properties of flood namely frequency,
duration, and magnitude on twelve (12) months scale. Annual rainfall spanning a period of fifty
(50) climatological years was obtained from the Nigerian Meteorological Agency (NIMET)
Oshodi, Lagos and was subjected to SPI model to reveal the occurrences of floods over the years
under study. The results of trend analysis revealed positive trend over the two stations but
statistically not significant at 95% confidence level. The increasing rainfall trend has a
repercussion on the incidence of flood. While findings of SPI analysis explicitly revealed that the
study area is generally replete with all categories of floods ranging from mild, moderate, severe
and extreme. The findings could be helpful to agencies like state emergency management agency
(SEMA) on purposeful developmental planning process, decision-making and proactive
management of the flood disaster. The research concludes that flood occurs variably time by time
in specific periods