What does chlorophyll have to do with archaeology? Well nowadays, it has a lot to do with it. A team from Pompeu Fabra University (UPF) is observing the vegetation of 20% of the territory of South America in search of archaeological sites. The vegetation, yes. They are scanning around 3.5 million km2 of Colombia and Brazil, basically of Amazon rainforest and savannah, with various technologies in search of differences in plants that reveal human passage, in places that were occupied by settlements or that were cultivated, subsequent plant colonization marks differences that can be detected by appropriately trained algorithms. They can also discover shapes in the landscape that may correspond to old settlements or cultivated areas. Could unknown cities appear deep in the jungle? “If we accept any type of human settlement as a city, there is no doubt that they could appear”, smiles the project director, Marco Madella.
The research is called Mapping the archaeological pre-Columbian heritage in South America (Maphsa) and is part of the Culture, Archeology and Socio-Ecological Dynamics Research Group (CASES) of the Humanities department of the UPF. It has just received a generous donation of 1.9 million euros from the Arcadia Foundation, an American cultural sponsorship organization. The team is made up of 18 people, five of them from this Catalan university. The work started in January and will last about three years.
The aim of Maphsa is to create – in English, Spanish and Portuguese – a geospatial database, nourished with already existing material, with capture by means of remote aerial sensors and with studies on the ground, which discovers unknown human settlements. One of the tools that will be used is the Lidar (light detection), which quickly scans thousands of square kilometers and is even able to reveal the relief through the jungle. At a very high price, yes, both for the aerial work and for the subsequent processing of the data. Only in the Brazilian area that will be analyzed today, around 9,000 settlements have been detected, and it is estimated that a similar number of new sites may appear. Maphsa will train several types of algorithm to adapt to different types of landscape.
“A great advantage is that we go to areas that, for geographical, political or logistical reasons, are not practicable”, explains the research coordinator. “In the south of the Amazon, in the state of Acre, there are large areas in danger due to agricultural and livestock expansion and the exploitation of wood, and the Cerrado, also in Brazil, is an area of savanna where there are great coffee and agricultural interests”, he adds. The Maphsa aspires to be a tool for evaluating the preservation of places of interest and also for real-time detection of potential threats. It will do this by programming algorithms that know how to identify the different tones of vegetation or shapes in the landscape that may correspond to towns or cultivated areas.
One of the requirements of the Arcadia Foundation is that the data obtained is publicly accessible, which, on the other hand, can create some conflicts. For starters, if reveals the exact location of sites that could be candy for archaeological looters. And second, if it highlights places where there are economic interests: the fact that there are untouchable places, such as archaeological sites, is a problem for these interests. “We have to fulfill Arcadia’s mandate, so there will be open data for a first level of research, but so we will have filters for precise geographic location, and we will evaluate requests. We will offer the data to each country to use in the way it sees fit. We are neither an agency nor the local cultural authority. We will limit ourselves to making suggestions”, explains Madella. “We will be able to monitor the risks to cultural heritage by detecting urban or agricultural expansions, or forest fires, and from here we can alert local agencies practically in real time,” adds Jonás Gregorio, a Brazilian archaeologist who is a member of the team.
The idea of ??Maphsa is to bring to the end of the process a minimum of three expeditions on the ground: one in the Brazilian Cerrado and two in the jungle, one in each country. Prospecting is currently limited to almost all of Colombia and part of Brazil, but they plan to include more South American territory.
“It could be that cities appeared in the Colombian jungle, understanding that a city is a settlement of much more modest dimensions than we can think. In the Amazon there is no stone, there is earth and wood. In terms of population, rather than urban planning, we can indeed consider that there could have been cities in the jungle, the Amazon is not virgin nature, it has been modified, but in a sustainable way, for thousands of years. Here the balance has been good, nothing to do with the European and Western mentality, of exploitation and enrichment, there was always a balanced and sustainable use between nature and humans”, remarks the archaeologist.
“6,000 years ago there were also periods of drought there, there were population declines, although the Amazon showed great resilience. In the plains of Bolivia, for example, there were areas that were abandoned for climatic reasons before 1492, we know that there was a small ice age that changed human uses”.
This research is an obvious example of the technology that is transforming archeology in recent years, thanks to the use of disciplines or advances in other disciplines. Archaeologists work at Maphsa, of course, but also computer engineers, computer science graduates or geologists. In addition to the UPF, the Leiden Institute of Advanced Computing of the University of Leiden (Netherlands), the Catalan Institute of Classical Archeology (Tarragona), the Museum of Archeology and Ethnology of the University of São are involved Paulo (Brazil), the National Institute of Space Research of Brazil and the University of Magdalena (Santa Marta, Colombia). Together, they will also collaborate with the National Historical and Artistic Heritage Institute and the National Archeology Center, both of Brazil, and the Colombian Institute of Anthropology and History of Colombia.
