Defocused people wading in Brazil's Rio Vermelho or Red River with focus on a leaf in the foreground during a drought

rio vermelho river araguaia river sobradinho flowing wading runoff water nature shallow red river brazil tributary environmental goias recreational natural topless wetland low level pollution climate change ecosystem defocused watercourse savanna focus global warming precious people source habitat rapid drought crisis precipitation drink surface agriculture leaf shortage resource scarcity tree valuable quantity fresh usage supply