Aerial photogrammetry with UAV as a tool for the conservation of archaeological sites - Case study: La Esperanza Complex

Abstract

Ecuadorian archaeology has focused especially on understanding the past of the Coast and Highlands regions, leaving the Amazon region behind, despite having a historical past of equal importance. The Upano Culture is the main pre-Columbian human settlement that inhabited the Upano valley, in what is now the Morona canton - southeast of Ecuador, whose archaeological sites are located on both banks of the Upano River; one of these is the mound complex known as La Esperanza. Due to urban sprawl and lack of protection by the responsible institutions, the conservation of these complexes is at risk. An alternative to collect information that allows to show the current state of the archaeological heritage is the use of UAVs. The present work aims to apply aerial photogrammetry with UAV to determine the state of conservation of the La Esperanza archaeological complex. Using a combination of GNSS positioning and the Structure
from Motion technique, photogrammetric products were obtained that showed a deterioration of the archaeological site, where only 28.6% of the original complex exists today. Thanks to advances in geosciences, UAVs can generate accurate and low-cost cartographic information that can be used as input for archaeological work.