Detecting Climate Change Trend, Size, and Change Point Date on Annual Maximum Time Series Rainfall Data for Warri, Nigeria

Abstract

The study focused on the detection of indicators of climate change in 24-hourly annual maximum series (AMS) rainfall data collected for 36 years for Warri Township, using different statistical methods yielded a statistically insignificant positive mild trend. The IMD and MCIMD downscaled model's time series data respectively produced MK statistics varying from 1.403 to 1.4729, and 1.403 to 1.463 which were less than the critical Z-value of 1.96. Also, the slope magnitude obtained showed a mild increasing trend in variation from 0.0189 to 0.3713, and 0.0175 to 0.5426, with the rate of change in rainfall intensity at 24 hours duration as 0.4536 and 0.42 mm/hr.year (4.536 and 4.2 mm/decade) for the IMD and the MCIMD time series data, respectively. The trend change point date occurred in the year 2000 from the distribution-free CUSUM test with the trend maintaining a significant and steady increase from 2010 to 2015. Thus, this study established the existence of a trend, which is an indication of a changing climate, and satisfied the condition for rainfall Non-stationary intensity-duration-frequency (NS-IDF) modeling required for infrastructural design for combating flooding events.

Reproductive Characters and Yield of Selected Drought Tolerant Maize Varieties in a Rainforest Agroecology of Nigeria

“…Several reports from studies conducted in the rainforest agroecology in Nigeria (Odjugo, 2010;Obot et al, 2010;Ayanlade et al, 2018;Gbode et al, 2019;Ogbu et al, 2020) allude to the fact that this threat emanates from alteration in the pattern of rainfall which had existed over the years. Among the parameters of climate change in Nigeria, rainfall is the most important (Ayinde et al, 2010;Sam et al, 2023). Consequent upon the reported alteration in rainfall pattern, the humid areas in Nigeria (including the location of the present study) have become prone to spells of moisture deficit (Layi-Adigun et al, 2020).…”