Determination of the Extent of Climate Variability and Climate Change in Rivers State, Nigeria

Authors

Climate change is one of the defining issues of our time. The

determination of the extent of climate variability and change in

any location is very vital for environmental study assessment

and proper planning. This study applied statistical analysis to

rainfall and temperature data in the Rivers State of Nigeria.

Climate Research (CRU 0.5 0.5) gridded data for 33 locations

from 1956 to 2016 were chosen because NIMET only has one

gauging station in the state. These data were sorted, validated

with NiMet data, and utilized for analyses of various time series

techniques such as Mann-Kendal, Spearman’s Rho, Linear

Regression, Thei-Sen Slope Cumulative sum, Cumulative

Deviation, Rank Sum, Student’s (t-test), and spectral analysis.

The results obtained revealed that there had been increasing

temperature and abrupt climatic changes in the state,

especially in the 1976-1985 decade, with 1980 as the most

probable year of abrupt change. The hottest decade was 1976-

1985, with an average temperature change of 0.1255 0C

/decade, while the coolest decade was 1996-2005 with an

average temperature change of -0.0132 0C/decade. Also, there

had been some changes in rainfall, with the wettest decade

occurring in 2006-2015 with an average rainfall change of

96.8 mm/decade, while the driest decade occurred in 1996-

2005with an average rainfall change of 29.7mm/decade. The

output of spectral analysis showed that the most significant

periodicity for rainfall and temperature was 15 years. The

result further revealed that there was high rainfall variability

with a coefficient of variability of 62.43%. There was a low-

temperature variability of 4.314%. These rainfall fluctuations

have implications for coastal flooding, quality, and quantity of

available groundwater in the state. These results are useful to

planners and policymakers in creating awareness of climate

change's impact on rainfall in the study area.