Spatio-Temporal Assessment of Desertification Sensitivity in the Sudan Savannah Zone of Nigeria: A 25-Year MEDALUS-Based Analysis

Idris, Muttaka; Komolafe, Akinola Adesuji; Chukwuemeka, Ochei Michael

doi:10.48311/ecopersia.2026.121996.82929

Spatio-Temporal Assessment of Desertification Sensitivity in the Sudan Savannah Zone of Nigeria: A 25-Year MEDALUS-Based Analysis

Document Type : Original Article

Authors

Muttaka Idris ¹

Akinola Adesuji Komolafe ²

Ochei Michael Chukwuemeka ³

¹ Department of Geography, Aliko Dangote University of Science and Technology Wudi ADUSTECH

² Department of Remote Sensing and GIS, School of Earth and Mineral Sciences, Federal University of Technology, Akure

³ Department of Meteorology and Climate Science, School of Earth and Mineral Science, Federal University of Science and Technology, Akure, Nigeria.

10.48311/ecopersia.2026.121996.82929

Abstract

Aims: Desertification threatens the balance of dryland ecosystems across Nigeria’s Sudan Savannah zone. This study applies the Mediterranean Desertification and Land-Use (MEDALUS) model to assess the spatio-temporal dynamics of desertification sensitivity in Jigawa and Yobe States over 25 years (2000-2025) at five-year intervals.
Materials & Methods: We integrated Landsat-derived Land-Use/Land-Cover (LU/LC) change detection with the MEDALUS quality index framework, an approach rarely applied at this temporal scale in the region. Soil (SQI), Vegetation (VQI), Management (MQI), and Climate (CQI) Quality Indices were combined to derive the Desertification Sensitivity Index (DSI); Mann-Kendall trend and Pearson/Spearman correlation analyses examined LU/LC-DSI relationships.
Findings: LU/LC classification accuracy exceeded 94% (Kappa >0.89) across all epochs. Over 54% of the study area was classified under High desertification sensitivity at every epoch, peaking with a Very High DSI share of 7.02% in 2015 - driven by soil quality decline and bareland expansion - before moderating to 2.98% by 2025. LU/LC recorded a net farmland loss of 5,571.71 km² and bareland expansion of 1,492.70 km² (2015-2025). These changes are consistent with anthropogenic pressure being associated with DSI intensification, rather than establishing it as the principal causal driver, alongside the climatic influences discussed below.
Conclusion: The findings highlight a persistently elevated but conditionally reversible desertification trajectory - the post-2015 amelioration being contingent on sustained land management and favorable climatic conditions rather than assured- emphasizing the need for land restoration policy and soil conservation strategies aligned with Nigeria’s Land Degradation Neutrality commitments and the African Union’s Great Green Wall Initiative.

Keywords

Desertification Sensitivity Index

Land-Use/Land-Cover Change

MEDALUS

Remote Sensing and GIS

Semi-Arid Region

Subjects

Desert Ecosystems

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