Rapid Mapping of Waterbody Variations in the Central Rift Valley, Ethiopia, Using the Digital Earth Africa Open Data Cube

Abstract

Mapping waterbodies variations through time is only possible thanks to the use of in-situ hydrometric sensors or remotely sensed data. Few areas around the world count with a functional in-situ sensor’s network, but all areas can be observed with satellite imagery. Several previous studies have mapped waterbodies by means of optical satellite imagery. Combining both optical and radar data is an alternative to avoid high cloud coverage or low data availability. This work presents a workflow for mapping waterbodies variations of lakes, spatially and temporally, located in the Central Rift Valley, Ethiopia by considering Landsat-based analysis-ready data alongside Sentinel-1/2 imagery, and comparing automatic thresholding methods. The workflow is simple, yet effective, and makes use of the Digital Earth Africa Open Data Cube, for the very first time in Ethiopia to accelerate time-series processing with the potential to extend this analysis to a national scale, addressing water security challenges.