Droughts, floods, and farming at Quebrada Tacahuay from late prehispanic to colonial times

Abstract

We describe diachronic evidence of moisture reduction and its consequences for coastal irrigation, agriculture, and settlement at Quebrada Tacahuay, a large drainage south of the Osmore River in far southern Peru. These observations are the first for a drainage of this size and for one with occupation spanning over 12,000 years for southern Peru. Following several millennia of occupation by coastal foragers, farming populations settled the lower elevations of the drainage. Our analysis indicates that agricultural production was well developed in the fourteenth century prior to a previously documented, catastrophic El Niño Southern Oscillation (ENSO) flood that took place sometime during the early-fourteenth century. Later in the fifteenth century the Inca conquest of the region and establishment of a coastal tambo and village was accompanied by agricultural expansion and the creation of new terraces. Subsequent Spanish colonization took place during the Little Ice Age and a period of increased coastal moisture. The historic and modern contraction of a large olive grove document the ongoing reduction in the coastal aquifer.