A sinkhole is a cenote, sink, sink-hole, swallet, swallow hole, or doline, is a depression or hole in the ground caused by some form of collapse of the surface layer. With area being swampy from the video, underground water current may have forced the water and vegetation to the inside.
From the details in the video, this geographical phenomenon may have been caused by the heavy rainfall that continue to pour across the country. The area in the video also seem to be swampy and this may explain why the vegetation around it were 'disappearing' underground.
Sinkholes can be natural or man-made. They are caused by either erosion or underground water. The video from Bomet strongly suggest that the sinkhole may have been caused by underground water.
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