Peru's ancient irrigation systems turned deserts into farms because of culture

Summary

Seeing the north coast of Peru for the first time, you would be hard-pressed to believe it’s one of the driest deserts in the world. Parts of the region receive less than an inch of rain in an entire year. Yet, water and greenery are everywhere. This is the nation’s agro-industrial heartland, and, thanks to irrigation canals, almost every inch of the floodplain is blanketed in lucrative export crops, such as sugarcane, asparagus and blueberries. However, the apparent success of this system masks an underlying fragility. Water shortages have plagued the region for centuries, and now modern climate change combined with agro-industrial practices have further intensified droughts. In response, the Peruvian government has invested billions of dollars in irrigation infrastructure in recent years designed to deliver more water from a resource more than 100 miles away: glaciers in the Andes. But the Andean glaciers are disappearing as global temperatures rise. Peru has lost over half its glacier surface area since 1962. At the same time, floods often connected to wet El Niño years are increasing in both frequency and intensity. These floods often destroy or obstruct critical irrigation infrastructure. Andean glaciers are disappearing as global temperatures rise. Peru lost over half its glacier surface area in the past half-century. mmphoto/DigitalVision via Getty Images As an archaeologist investigating societal responses to environmental and climate disaster in Peru, I’m interested in unraveling the histories of complex systems to understand how to improve similar systems today. To understand the Peruvian heartland’s vulnerabilities, it helps to look to the deep past. Most of the modern canal network originally dates to pre-Hispanic times, more than 1400 years ago. However, evidence suggests that while the canal systems of the past may have looked similar to those of the present, they functioned in more efficient, flexible ways. The key to adapting to our present and futur...