Most parts of Ethiopia have experienced severe drought conditions and poor agricultural output due to extreme climatic conditions. The Water Requirement Satisfaction Index (WRSI),1 a crop-specific performance indicator taking rainfall and soil characteristics into account, indicates extreme and increasing variability in recent years, as shown in the graphs below. Analysis of rainfall itself shows a similar pattern.
Virtually all food crop agriculture in Ethiopia depends on rainfall that is frequently erratic and unpredictable. Given widespread differences in Ethiopia's topography and elevation, it's necessary to look at the district (wereda) level to appreciate the unreliability of rainfall in recent years.
Based on long-term rainfall data (1961-2003), the WRSI has become unusually erratic in many districts, suggesting that recent declines are an aberration from previous history. The first graph of long-term WRSI for belg season maize for Awasa district in south-central Ethiopia shows increasing variability over the past 15 years. This variability has become even more pronounced in recent years, as shown in the second and third WRSI graphs for Goba district (south-central Ethiopia) and Sinana Dinsho district (south-eastern Ethiopia). The fourth graph for Bati district (north-central Ethiopia) shows extreme variability and estimated crop failure in the past three years.
Graphs for the meher season (through 2002, next page) show similar patterns. The first graph of long-term WRSI for meher season sorghum for West Gojjam Zone in the rainfall-dependable western highlands shows near constant WRSI (1961-2002) near the full saturation point of 100 percent. In contrast, the second and third WRSI graphs for Arsi (central Ethiopia) and East Shoa (central Ethiopia) Zones shows increasingly variable WRSI in recent years. The fourth graph for East Hararghe Zone shows a steady longer-term decline.
Note that the WRSI is based on historical potential crop yields and thus reflects performance relative to an upper bound of possible production. Crop production will be less when farmers cannot afford to plant improved seeds or apply purchased fertilizer or when labor constraints or land mines force farmers to decrease their area planted.
A look at rainfall alone shows a similar pattern of year-to-year volatility. Based on total annual rainfall between 1961 and 2002, 12 points were taken and averaged in the highland and midland regions of East and West Hararghe Zones (Oromiya Region, eastern Ethiopia). As shown in the final graph (last page), there is a clear downward trend in rainfall since 1984 and the last three years were the lowest in this time series.
Most rural households are able to manage the shock of a single poor rainy season and transit in and out of food insecurity when the rains resume the following season. However, the cumulative shocks of consecutive poor seasons may push some households into chronic food insecurity or even destitution. Many rural Ethiopians had not completely recovered from the 1999/2000 drought before they were hit by successive poor belg and meher harvests in 2002 and large-scale loss of livestock, particularly in Afar. Other factors also make it difficult for Ethiopian households to manage their own food security: rising staple food prices, collapsing coffee prices, slumping livestock exports and the growing specter of HIV/AIDS.
When considering additional factors, such as climate variability, rapid population growth, poor infrastructure, rugged terrain and soil degradation, it is clear that reliance on low-input, low-yield rainfed agriculture on small plots will not solve the pervasive problem of rural hunger and poverty. This makes it imperative for Ethiopia and its partners to boost crop and livestock productivity and rural incomes now as a way to address food insecurity in the short term.
1 The Water Requirement Satisfaction Index (WRSI) is a model of crop performance developed by USGS that takes rainfall into account. WRSI is based on the ratio of seasonal actual evapo-transpiration to the seasonal crop water requirement for a particular crop. A WRSI of 100 indicates optimum water supply for the crop, 80 is about average crop performance, while WRSI below 50 is considered a complete crop failure.