Spatio-temporal analysis of multiple stressors affecting pastoralism in Ethiopia

Keywords: vulnerability, pastoralim, Ethiopia, MODIS, EVI
Abstract Type: Virtual Paper Abstract

Abstract

Pastoralism is a traditional livelihood system crucial to the livelihoods and the economy of Africa’s drylands. Over the last decades, pastoral systems are becoming increasingly vulnerable due to climatic and non-climatic stressors, which spatial and temporal dynamics are not fully understood.

We examine the pressure mechanisms affecting pastoralists’ resources in Ethiopia associated with Land Use-Land Cover (LULC), rainfall, and greenness changes in pastoral grazing lands between 2000-2021. Used datasets include: CCI (European space agency), CHIRPS (UCSB CHC-USGS), and Enhanced Vegetation Index (EVI, MODIS), respectively.

Results show high rainfall and EVI inter-annual variability, consistent with droughts and floods events. Less than 5% of the area exhibits significant rainfall trends. These are positive and very localized, corresponding to the wettest areas for the most part. At monthly scale, significant trends are mostly associated with the driest months. Rainfall declines are observed in December in January, but also in March, a key transitional month for pasture regeneration. Spatially, three distinct areas of significant changes emerge where rainfall either increases or decreases part of the year or both, indicating increased rainfall variability. Over 96% of the area is characterized by LULC persistence. LULC transitions show increased land degradation and encroachment on grazing areas due anthropogenic conversions, with some increased vegetation areas. Of major concern is the expansion of Proposis juliflora in proximity of water resources which has been spreading into grasslands and rangelands.

Overall, results reveal a multi-stressor mosaic operating at different scales
and underscore the importance of multi-stressors and multi-scalar vulnerability assessment approaches.