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

Abstract Fluctuations in rainfall and Increased temperatures serve as indicators of Nigeria's climate change. Despite this, a comprehensive examination of climatic variables and their spatial distribution within Delta State remains lacking in existing 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 Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) and ERA5Land reanalysis datasets to analyze rainfall and temperature trends spanning from 1983–2023 in Delta State, Nigeria. The statistical significance of these trends was determined using the Mann-Kendall and Sen’s slope trend test. Additionally, ArcGIS 10. 7 was used to map the region's spatial distribution of rainfall and temperature. The results show 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. In the case of temperature, the result shows 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.