Characterization of Present Day Climate Trend Over Ethiopia for Impact Study

Abstract

Understanding climate variability and its change over Africa is an issue of increasingly importance. The society and its economy are strongly dependent on agriculture where substantial proportion of this agriculture is rain-fed. To address this issue, climatological analysis was carried out based on observed climatological data from gauges. The study provides climate information in space and time for climate change impact assessments. The degree of variability is measured based on the temporal trend using a linear regression model at 95% significance level. To be confident enough, the spatial climatological features from gauge are compared with CRU climatologies which is in good agreement. Some differences between CRU and gauge datasets are observed that might be related to the coarse resolution of CRU to capture the fine scale climatological patterns. Results show that statistically significant maximum temperature increasing trends are detected during summer (JJAS) and spring (FMAM) seasons in the range between 0.1 and 0.01 °C season−1. In the case of rainfall, it has been observed that statistically significant decreasing trend at a smaller rate over larger area especially for JJAS. The weak down-trend in rainfall and fast up/down-trend in temperature require impact modeling for optimizing management options of crop and hydrological resources over Ethiopia.