Publications

Okoduwa, AK; Mokhtarisabet, S (2025). Spatiotemporal analysis of drought in the Sahelian region of northeastern Nigeria, sub-Saharan Africa. THEORETICAL AND APPLIED CLIMATOLOGY, 156(6), 293.

Abstract
Drought frequency and severity have intensified in recent decades due to climate change, posing significant threats to ecosystems and livelihoods in the Sahelian region of northeastern Nigeria. In response to these growing challenges, this study aims to analyze the spatiotemporal variations in drought conditions from 2001 to 2024 by integrating multiple remote sensing-derived indices with climatic data to assess both ecological and socio-economic impacts. Unlike previous studies that primarily relied on precipitation-based indicators, this research incorporates a broader approach by combining vegetation-based indices-including the Vegetation Condition Index (VCI), Normalized Difference Vegetation Index (NDVI), and Vegetation Health Index (VHI)-with temperature-based indices such as the Temperature Condition Index (TCI). This integration allows for a more nuanced understanding of drought impacts by linking vegetation stress, temperature anomalies, and rainfall patterns across diverse agro-ecological zones. To comprehensively capture the complexity of drought dynamics, advanced statistical techniques, including trend analysis and multiple correlation tests, are employed to reveal different relational patterns between indices. The results reveal significant fluctuations in drought severity, highlighting critical drought periods and persistent aridity in states such as Borno, Yobe, and Gombe. Thermal stress, measured through the Temperature Condition Index, peaked at 16,263 km(2) in 2001, declined to 6,909 km(2) in 2013, and increased again to 9,945 km(2) by 2024. Meanwhile, the Vegetation Condition Index indicates sustained vegetation stress, with drought-affected areas expanding from 109,566 km(2) in 2001 to 126,606 km(2) in 2024. These prolonged dry conditions have severe implications for agricultural productivity, water resources, and rural livelihoods-particularly among pastoralist and farming communities-exacerbating food insecurity and economic instability in the region. By offering a multi-index, long-term assessment of drought dynamics, this study provides critical insights for policymakers and resource managers. The findings underscore the urgent need for targeted climate adaptation strategies, such as improved water resource management, early warning systems, and sustainable land-use practices, to mitigate the escalating risks of climate-induced drought in the Sahelian region.

DOI:
10.1007/s00704-025-05542-8

ISSN:
1434-4483