TITLE:
Interannual Variability of the NDVI in East Africa during 1983-2022 and the Climate Impact
AUTHORS:
Emmanuel Lusoloja Mabula, Yi Fan, Daniel Stephene Semgomba
KEYWORDS:
East Africa, NDVI, Interannual Variability, Wet Years, Drought Years
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.13 No.1,
January
23,
2025
ABSTRACT: The interannual variability of Normalized Difference Vegetation Index (NDVI) over East Africa demonstrates the complex interactions between vegetation dynamics and climatic factors. This study, which spans the period from 1983 to 2022, makes use of data from NOAA, ERA5, and CRU. It employs a range of statistical techniques, including the calculation of standardized anomalies, significance testing, composites and correlation analyses. The results demonstrated an increase in NDVI over regions including Kenya, Central and Northeastern Tanzania during wet years, with significantly higher NDVI compared to drought years. Conversely, regions such as Uganda, Rwanda, Burundi, and parts of western and southern Tanzania exhibited lower NDVI during wet years than in drought years, thereby underscoring the existence of significant regional differences in vegetation responses to climatic conditions. The results of the correlation analysis indicated that there was a negative correlation between NDVI and SLHF, air temperature, and soil temperature, while positive correlations were observed between NDVI and SSHF, precipitation, and soil moisture. Furthermore, teleconnections with large-scale climate indices demonstrated modest correlations: Niño 3.4 (r = 0.33), DMI (r = 0.11), and AMO (r = 0.03). These findings emphasize the pivotal role of climatic and meteorological factors in influencing vegetation dynamics, offering insights for sustainable land management and climate adaptation strategies in East Africa.