In these images, bright green indicates aquatic vegetation on the Omo River delta. The size of the delta changes over time in these scenes because of changes to the lake’s water level. The delta expands and shrinks in response to the high rainfall variability in the region. However, if a significant amount of water is diverted from the Omo River for irrigation, the natural dynamics of the lake levels could be affected.
In the 2011 and 2015 images, curious features appear: green swirling shapes south of the delta. We know that green indicates growing vegetation in these images, but is this shallow water being exposed with more aquatic vegetation taking hold, or is this vegetation floating on the water’s surface? Examining the lake’s depth reveals that it is too deep in this area to be growing, rooted plants. So it must be vegetation or weeds floating on the surface.