Spatial Scale Effects on the Relationship Between Land Use/Land Cover Change and Potential Evapotranspiration in Niger State, Nigeria

• Muhammad M. ABDULLAHI

  Author

• Iyanda M. ANIMASHAUN

  Author

• Ibrahim A. ABDULFATAI

  Author

• George U. STEPHEN

  Author

Potential evapotranspiration (PET) is a major climatic variable for irrigation planning, drought monitoring, and water-resources management, and its spatial distribution may be modified by land use/land cover (LULC) change. This study aimed to (i) quantify LULC changes in Niger State between 2004 and 2024, (ii) characterize the temporal and spatial patterns of PET, and (iii) determine whether the strength and direction of the LULC–PET relationship vary with spatial scale. Landsat 5 TM, Landsat 8 OLI, and Landsat 9 OLI-2 imagery were classified at 30 m using supervised Maximum Likelihood Classification for six LULC classes. PET was estimated with the Hargreaves method from Climate Research Unit climate inputs. An analytical dataset comprising 500 grid cells and three observation years (1,500 observations) was analysed at grid-cell, Local Government Area (LGA), and state-wide scales using percentage-change analysis, Pearson correlation, t-tests/ANOVA, and Mann–Kendall and Sen’s slope trend tests. Grassland increased to 74.51% of the state by 2024, while built-up area increased from 0.19% to 1.14%. At grid-cell scale, PET was positively correlated with Forest (r = 0.83) and Cropland (r = 0.74), but negatively correlated with Built-up Area (r = −0.70), Grassland (r = −0.64), and Waterbody (r = −0.58). State-wide mean annual PET changed by only 0.52% and did not differ significantly among the three observation years (p > 0.05), although spatial variability increased. The results demonstrate a scale-dependent LULC–PET relationship and indicate that grid-cell and LGA-scale evidence is more informative for localized irrigation, drainage, land-use, and climate-adaptation decisions than state-wide averages.

• 53_Abdullahi et al. (2026)

Copyright (c) 2026 Muhammad M. ABDULLAHI, Iyanda M. ANIMASHAUN, Ibrahim A. ABDULFATAI, George U. STEPHEN (Author)

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