The Okavango Delta (or Okavango Swamp), in Botswana, is the world’s largest inland delta. It is formed where the Okavango River empties onto a swamp in an endorheic basin in the Kalahari Desert, where most of the water is lost to evaporation and transpiration instead of draining into the sea. Each year approximately 11 cubic kilometres of water irrigate the 15,000 km² area. Some flood-waters drain into Lake Ngami. The Moremi Game Reserve, a National Park, spreads across the eastern side of the delta. The area was once part of Lake Makgadikgadi, an ancient lake that mostly dried up by the early Holocene.
The Okefenokee is a rainfall -dependent system, and when periods of drought occur, the area becomes susceptible to wildfire .  A 20-to-30-year cycle of drought and fire has allowed the Okefenokee to exist as the unique wetland it is.  These periods cause changes in the abundance of certain plants (more grasses growing in exposed areas) the nesting success of certain wading birds (failure in extreme drought), and the location of some species of wildlife (fish migrate into deeper lakes and channels and are followed by predators).