Multimodel and Vegetation Indices for Drought Vulnerability Assessment: A Case Study of Afar Region in Ethiopia

Abstract

Drought is a water related climatic natural disaster affecting wide range of environmental, biological and social factors. Short, poor and delayed rainfall in 2015 caused critical water shortage, livestock causality and decline in milk production in the pastoral areas of Ethiopia. The relationship between rainfall and vegetation indices was analyzed to identify drought-vulnerable areas in Afar region of Ethiopia using 11 years time series of decadal NDVI, VCI, DSI and SPI using SPOT (2005-2013) and PROVA-V (2014-2015) data. For the validation of drought indices, correlation and regression analyses between NDVI and rainfall (r = 75%), NDVI and crop yield, and VCI and rainfall (r = 90%) were done. The findings showed that there was extreme drought in the Afar region in 2005, 2009, 2011 and 2015. The region was highly prone to drought, even though its severity levels varied in different years. Drought was severe, longer and intense in most of the areas in the region, adversely affecting agricultural productivity and livestock maintenance and management. Assessments of such natural disasters are useful to plan mitigative measures in advance for effective management programmes, including drought hazards.