Geospatial-based climate variability analysis, in Central Ethiopia Rift Valley

Climate variability has been a crosscutting issue across the globe, where the effect is more adverse in developing countries such as Ethiopia. The study aimed at investigating climate variability of Ziway Dugda and Dodota Woredas, Central Rift Valley, Ethiopia. The study has used 1983–2012, time series gridded data, field survey, and normalized difference vegetation index (NDVI) data. The data were thoroughly processed and analyzed using combination of Geospatial technologies and descriptive statistics. Long-term (1983–2012) rainfall data analysis result revealed an increasing trend, with an overall mounting rate of 78.5 mm in three decades period and it is also characterized by inter-annual fluctuation. The mean maximum total rainfall analysis of the same period divulges a consistent pattern, distinctively featured by late-onset and early cessation of rainfall. It is found that the maximum temperature increased by 0.23 °C per decade with an overall rise of 0.7 °C in the 30-year period of concern, while the minimum temperature remains constant. The statistical correlation result signposted a linear positive correlation between NDVI and mean annual and spring season rainfall with r² value of 0.3467 and P value of 0.0342, and r² of 0.715 and P value of 0.0003, respectively. Indisputably, variability of rainfall, and minimum and maximum temperatures was observed. The analysis also stipulated that climate variability is pervasive particularly in the spring rainy season, substantially dwindled in its amount and distribution, and eventually afflicts the vegetation condition and crop production in the milieu. Therefore, as climate variability has been highly manifested in the study area, appropriate policy and strategic measures are required to reduce and mitigate the consequent impacts.