The Northern Nigeria Region (NNR) has historically suffered from land productivity changes due to anthropogenic and climatic factors. The development of methodologies that can evaluate these changes at the pixel level and spatialize the effects of driving factors is a key requisite to provide targeted solutions for land degradation, in a country with population growth and desert advancement. In this study, we applied MODIS series data to assess land productivity changes in the NNR (2001–2021) using NDVI trend analysis. We also used correlation and RESTREND analyses to discriminate between climate and human factors and map their effects. The results indicated that approximately 30.7% of the NNR showed land degradation, whereas 27.1% showed an increase in land productivity. There was a clear spatial pattern, with increasing productivity closer to the northern Nigeria boundary with Niger, and decreasing productivity concentrated in the central and southern parts of the NNR. Anthropogenic factors had a greater impact on land degradation and improvement, compared with rainfall. The climate forcing contributed most to land productivity in the northeastern part of the NNR. Land degradation is mainly associated with overgrazing and unsustainable agricultural practices, which lead to decreasing productivity of grasslands and crops. On the other hand, human influence on improvements involves land abandonment and recovery programs. These results can be used to planning initiatives to better integrate food production with environmental protection in the NNR, contributing to policies to Nigeria achieving land degradation neutrality as soon as possible.

中文翻译：

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气候变化与人类活动：它们在塑造尼日利亚北部土地生产力中的作用


由于人为和气候因素，尼日利亚北部地区 （NNR） 历来遭受土地生产力变化。在一个人口增长和沙漠发展的国家，开发能够在像素级别评估这些变化并将驱动因素的影响空间化的方法是为土地退化提供有针对性的解决方案的关键先决条件。在这项研究中，我们应用 MODIS 系列数据，使用 NDVI 趋势分析来评估 NNR （2001-2021） 的土地生产力变化。我们还使用相关性和 RESTREND 分析来区分气候和人为因素并绘制其影响图。结果表明，大约 30.7% 的 NNR 显示土地退化，而 27.1% 显示土地生产力增加。存在明显的空间模式，尼日利亚北部与尼日尔边界附近的生产力增长，而生产力下降集中在 NNR 的中部和南部。与降雨相比，人为因素对土地退化和改良的影响更大。气候强迫对 NNR 东北部的土地生产力贡献最大。土地退化主要与过度放牧和不可持续的农业做法有关，这导致草原和农作物的生产力下降。另一方面，人类对改进的影响涉及土地撂荒和恢复计划。这些结果可用于规划举措，以更好地将 NNR 中的粮食生产与环境保护相结合，有助于尼日利亚尽快实现土地退化零增长的政策。