Spatial Distribution of Climate Change Variables (Rainfall and Temperature): A Case Study of Delta State, Nigeria

Abstract

Fluctuations in rainfall and increasedtemperatures serve as indicators of climate change in Nigeria. However, a comprehensive examination of climatic variables and their spatial distribution within Delta State is lacking in the literature. Previous studies on climate change predominantly rely on data from ground-based monitoring stations. However, these stations fail to cover all geopolitical zones within Delta State, posing significant challenges to climate monitoring research. To address this research gap, this study employs the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) and ERA5_Land reanalysis datasets to analyzerainfall and temperature trends spanning from 1983-2023 in Delta State, Nigeria. The statistical significance of these trends was determined using the Mann‒Kendall testand Sen’s slope trend test. Additionally, ArcGIS 10.7 was used to map the spatial distribution of rainfall and temperature in the region. The results revealed a decreasing trend in rainfall from 1983-2023. However, this decreasing trend was not statistically significant (p-value> 0.05). Spatially, rainfall has been decreasing in certain regions of Delta State. For the temperature, the results show an increasing trend from 1983-2023. This increasing trend in temperature was statistically significant (p-value < 0.01). The spatial map shows that Oshimili North, Oshimili South, certain areas of Burutu, certain areas of Warri South West, and some parts of Warri North experienced the highest temperatures throughout the study period. The study's findings will be helpful to environmental managers and policymakers in developing creative strategies to lessen the negative effects of climate change.