Development of a Parametric Flood Frequency Curves of Rainfall Magnitude Associated with Return Periods

A relationship between rainfall magnitudes and return periods for River Kaduna catchment meteorological stations is developed in this study. The K. NN algorithm was used to simulate the future rainfall values, using a transitory window of 14 days, a weather generating model was used to test the summary of statistical data. Auto and cross correlation tool was use to compare the relationship between rainfall magnitudes of the stations. For each rainfall duration, sample mean and standard deviation of the series of annual maximum values was used to estimate rainfall intensities values associated with return periods. The Gumbell tool was also used to standardized the character of rainfall across stations with varying length of record and used to compute rainfall magnitudes The inter relationship showed that rainfall magnitude increase with return periods and that data from gauged station can be transferred to other stations within a catchment area. Results from the relationship will serve a tool for understanding the variation between gauged and ungauged meteorological stations. The developed curves can be used to pick parameters for the design of hydrologic, hydraulic and water system