Yield and yield-reduction in recent drought years in southern Tigray, northern Ethiopia: Implications on food security

Abstract The consequences of prolonged precipitation-deficient periods are primarily substantial water deficit, with the spatial characteristics of drylands and various socioeconomic factors worsening its impacts and deepening poverty among agrarian communities, with attendant food security implications. This study utilizes a combination of climate, remote sensing and field survey data. These data were used to obtain a first-hand information on the impacts of recent (2015 and 2017) droughts on crop yield in southern Tigray, northern Ethiopia. Annual and seasonal rainfall, annual and seasonal NDVI and Dev-NDVI, and monthly SPI-1, SPI-3 and SPI-12 (for June to October) were considered as likely factors that could relate with yield and yield loss in the area. Correlation and multiple linear stepwise regression statistical techniques were used to determine drought-yield relationships, and identify more accurate predictors of yield and yield losses in each of the drought years. The area witnessed a more widespread precipitation deficit in 2015 than in 2017, where the lowland area recorded entire crop losses. Also, droughts manifested spatiotemporal variations and impacts across the 3 different agroecologies – primarily reduction in vegetation amounts, coinciding with the planting and maturing stages of crops. Crop failures therefore translated to food shortages and reduced income of smallholders, which denotes food insecurity in the time of droughts. Seasonal rainfall and June Dev-NDVI predicted 66.9% of 2015 yield loss, while NDVI predicted 2017 sorghum yield by 96%. Spate irrigation should be further popularized in the low-lying areas of Raya Azebo to augment for future deficiencies in the kiremt rainfall.