Evaluation of Climate Change Impacts on Maize Crop Water Requirements in Gamo Zone, Southern Ethiopia, for Exploration of Adaptation responses

Abstract

Gamo Zone is one of the most vulnerable area to climate change and often signifies higher probabilities of droughts that have historically affected rural poor farmers. This study has been carried out to fill a research gap of past and future climate change analysis and the impact on crop water requirement for proposing both anticipatory and reactive adaptations options. Meteorological data and climate model output data were obtained from National Meteorology Agency and ESGF portal respectively. Representative concentration pathways RCP4.5 & RCP8.5 scenario was selected to make future projections in three time periods (2011-2040, 2041-2070 and 2071-2100). The variability in rainfall patterns and drought have disrupted crop production and exacerbated food insecurity in many parts of the study area. A relative increase in the mean amount of annual rainfall is observed in all future periods with higher values in 2080s and RCP8.5. Additionally, gridded maximum and minimum temperature were used from the latest version CRU-TS4.0. A slight increase in both maximum and minimum temperature is observed with a relative higher value at the end of 21st century. Due to these the computed future evapotranspiration is higher as compared to reference period. Maize crop mean water requirement was also computed during different periods for both February and July Planting respectively. Similarly, crop water requirement increases in future periods. Field-based interviews and surveys for perception and understanding of the local people were made. Climate change adaptation strategies was identified based on the results of data analysis and field surveys which would contribute to decision making at study area. Soil and water conservation method is one of the best adaptation strategies in the study area.