INNOVATIVE TREND ANALYSIS OF HYDRO-METEOROLOGICAL VARIABLES IN IBADAN, NIGERIA

Abstract

Analysis of trend in hydro-meteorological variables is extremely important for improving water resources planning and management. This study examines trend in monthly rainfall and temperature using the recently developed Innovative Trend Analysis Method (ITAM) and Mann-Kendall (M-K) with Sen’s slope test. Record of precipitation and temperature data was obtained from the International Institute of Tropical Agriculture (IITA) in Ibadan, Nigeria for the period of 1973-2018. The precipitation trend during the period of 45years has been analyzed using the ITAM and M-K test. Most of the results obtained from these two methods for detecting trend are found to be matching. The result of this study shown that precipitation for the month of February, March, April, May, June, July, August and September indicated an increasing trend with the rate of 0.01, 0.01, 0.004, 0.025, 0.063, 0.028, 0.006 and 0.061 mm / year respectively. A significant increasing trend was shown in June and September at 1% and 10% significance level. The result of temperature obtained over the study area shown that almost all the months indicated increasing trend. The month of February, April, May and November shown an increasing trend at 10% significance levelThe comparison of the ITAM and M-K methods support the reliability of ITAM. In fact, ITAM detected some trend properties which could not be observed from the M-K test. Therefore, in climate change scenarios the ITAM can be effectively used and can provide useful information for precise management and planning of water resources.