DEVELOPMENT OF RAINFALL INTENSITY–DURATIONFREQUENCY (IDF) CURVE FOR KASTINA, NIGERIA

ABSTRACT
Every year damage cause by flood waters becomes major concern in
different communities across Katsina state and entire nation, mostly these
flood waters appear unusual causing sever damages to life and properties.
This unusual damage by flood water is cause due to proliferation in green
house gases, which is rapidly changing hydrologic cycle which varietal
events. Since rainfall characteristics are very important in planning and
design of different water resources project, reviewing and updating these
characteristics are very important in planning and design of different water
resources project such review and updating become necessary. [i.e.,
intensity-duration-frequency (IDF). The reason of this study was to
develop rainfall IDF empirical equations for Katsina city and environs, 47
years (1997-2017), data got from the Nigeria meteorological agency
(NIMET) Abuja, was used to estimate the short duration rainfall intensity
using yearly maximum rainfall data. Gumbel extreme – value and log
Pearson III distribution methods was used to develop IDF and equations.
It was found that log Pearson III distribution fits the data best, and also
intensity of rainfall decreases with increase in rainfall duration, further, a
rainfall of any given duration will have a larger intensity and its return
period is large.

Keywords: Rainfall Intensity, Return Periods, Rainfall Duration, Rainfall