"MUCUM, Brazil - Devastating and ongoing flooding in southern Brazil is forcing some of the half million displaced residents to consider uprooting their lives from inundated towns to rebuild on higher ground.
Two weeks after the onset of torrential rains, the Guaiba River running by state capital Porto Alegre is rising again, having passed the all-time high. In the state of Rio Grande do Sul, the streets of dozens of towns have turned into slow-moving rivers.
Just in the area around Porto Alegre, where four rivers converge to form the Guaiba River, researchers estimate nearly 3,800 square km (1,500 square miles) were flooded. That is more than the urban footprint of the Washington DC metro area, which includes 10 counties in two adjacent states.
With hundreds of thousands of families fleeing the floods, the disaster - which has killed at least 147 people, with 127 still missing - could touch off one of Brazil's biggest cases of climate migration in recent history."