The São Francisco River delta in Brazil has been affected by climate changes and human activities. The delta was mainly formed during periods of high river flow and rainfall in the past. However, since around 1,000 years ago, the river has only been able to maintain its shoreline without much growth. Recent erosion at the delta was triggered by decreased rainfall and river regulation after 1985, causing the river mouth to erode while sediments moved downstream. The erosion was not due to dams holding back sediment but rather changes in how the river flowed. Overall, the shoreline has been stable upriver while eroding at the river mouth.