Multiple Indices Based Agricultural Drought Assessment in the Rift Valley Region of Ethiopia

Abstract

Climate extreme like drought significantly affect the quality of the environment and threaten food availability in developing countries like Ethiopia. In this study, satellite-based agricultural drought assessments were conducted in the 0main crop growing season (June to September) using Landsat 8 images of five periods (2015 to 2019) in the Rift Valley Region of Ethiopia. To assess the agricultural drought we used Normalized Difference Vegetation Index (NDVI), Land Surface Temperature (LST), Vegetation Condition Index (VCI), Temperature Condition Index (TCI), and Vegetation Health Index (VHI). The results indicate that the main crop growing season was experienced by drought and wet which vary from extremely dry to extremely wet. The value of VHI, the cumulative effects of TCI and VCI, revealed that 2016 was the most drought-prone while 2019 was the wettest year. Results of NDVI and LST showed a negative correlation. Results showed that drought was more severe in the lowland areas than highland areas in the study area. Accordingly, high drought was observed in the northern and central parts of the study area. It is obvious that the lowland areas face a precipitation deficit because of high temperature and evapotranspiration. This study suggests that satellite-based indices were crucial to provide early warning systems for the farming communities and to suggest adaptation options that minimize the potential impacts of agricultural droughts on people's livelihoods and wellbeing. Moreover, further research should be conducted by incorporating other social and biophysical factors to enhance the understanding of agricultural drought and its effect on the economy of the agricultural communities.