Fields of Sand Dunes Along Coast of Northeast Brazil2.8S 40.5W
The northeast of Brazil (known locally as the Nordeste region) is characterized by semi dessertic weather and characteristics such as hot and dry temperatures, drought, lack of or scant rainfall, eroded soil and high evapotranspiration. Many coastal areas in region are covered by vast ﬁelds of active and stabilized coastal sand dunes.
Scientific studies show the vast prevalence of active sand dunes along the coast of NE Brazil in a tropical climate (average yearly rainfall above 1000 mm) results from the high powered trade winds, mostly during the dry season. Many stabilized dunes are found along this coast, side by side with the active dunes. A hysteresis model based on changes in wind power can explain the co-existence of stabilized and active dunes in the same area.
Vegetation on sand dunes in NE Brazil thrives when the rainfall is above 400 mm and the wind power is low. The dunes during the wetter periods were stabilized by vegetation due to low wind power and not because of the increased precipitation (click here for more information).