Abstract:
This study was conducted to characterize rainfall and temperature variability and their effects on
Wheat and Barley production in the study area. Daily and dekadal gridded climate data was
collected from National Meteorological Agency of Ethiopia (NMA) and National Oceanic and
Atmospheric Administration ( NOAA, USA). Temporal rainfall variability was assessed through
the timing of onset date, end date, length of growing season and dry spell length using INSTAT
climate guide. The year to year rainfall variability was also assessed using rainfall anomaly
analysis. The long-term annual rainfall in the study area showed 21%-29% variability on
temporal scale. Annual and seasonal temperature variability was assessed using the standardize
anomaly analysis. On the other hand, monthly temperature variability was assessed using
INSTAT climate guide. Seasonally, The MAM total rainfall showed higher variability 43%-61%
than the JJAS total rainfall 20%-33% respectively. The average SOS at Lat.13.27ON and at
Lon.39.30OE in the Central and at Lat.13.24ON and Lon.39.38OE in the Southeast to the study
area was 02July and 25June followed by an average EOS 17September and 14September with
an average LGP 79 and 87 days respectively. Minimum and maximum temperatures showed an
increasing trend both annually and seasonally. The observed high probability occurrence of dry
spell days, higher rainfall and temperature variability, early EOS, less stable and late SOS of the
main/JJAS and/or MAM seasons indicates that rain fed crop production in the study area was at
risk of water stress for the last 30 years (1980-2010).
