Deterministic Seismic Hazard Analysis of Grand Ethiopia Renaissance Dam (GERD)

This paper presents the Deterministic Seismic Hazard Analysis for Grand Ethiopia Renaissance Dam (GERD) (11.2183ºN, 35.0941ºE). This area is of special importance because GERD is the largest hydroelectric power plant in Africa and the seventh-largest in the world. The Hazard analysis was done using linear sources present near the dam site (Inferred faults and Indicated faults); 713 faults were used for the analysis. Earthquake data was collected for the dam region, and homogenization of data was done to moment magnitude followed by declustering foreshock and aftershock events. 1375 earthquakes of moment magnitude 4–7 were considered and represented on a seismotectonic map. Ground Motion Prediction Equations (GMPEs) were identified for the dam site, and suitability was checked by comparing the Data Support Index (DSI) value of various prediction equations. Considering the selected GMPEs and input data, DSHA was performed by using a MATLAB program developed for this purpose. The dam site was further divided into a grid cell of 100 m × 100 m, and hazard parameters were obtained at the midpoint of the grid cells, bearing in mind all seismic sources within a 500 km radius. Obtained PGA values were compared with USGS developed Instrumental Intensity scale. The hazard map showing the spatial variation of the risk associated with the dam site is presented.