Abstract

Drought indices are vital tools to play a significant role by monitoring drought in specific geographic environment/ over the globe. The major goal of this investigation is to assess the spatiotemporal variant of climatological drought using RDIst and SPI in Boricha District. This study adopted the long-term gridded rainfall and temperature information in six stations since (1985-2016). The spatial distribution of drought is mapping by using ArcGIS 10.3 spatial analysis tool and interpolated using IDW technique. During spring season two extreme droughts were located in station_2 and 3 with the same SPI values of (-2.26). During summer season in station_3, one extreme drought was detected with SPI values of (-2.32), in station_4 one extreme drought was noticed with SPI values of (-2.14). In 12months RDIst timescale, one extreme drought was identified in station_4 during 2012 with RDIst value of (-2.25), and in station_6 one extreme drought has been happened during 2009 with RDIst value of (-2.23). The study area is affected by slight/ mild to extreme droughts at all time scale. Analysis of correlation is conducted between SPI and RDIst to confirm the power of drought indices. MK trend test recognizes the tendency of drought was reduced and statistically insignificant in spring and annual timescales except station_1 at 12 months SPI. There is no weather station without drought in the region. All parts of the region are under drought risk, it needs immediate intervention by the regional and federal disaster risk preparedness and natural resource office to save residents and natural environment.

Keywords: Woynadega; Kola; Boricha; Ethiopia