New environmental and spatial approach to Tiwanaku World Heritage site (Bolivia) using remote sensing (UAV and satellite images)

This paper analyses the research carried out in the Tiwanaku World Heritage site in Bolivia, using Unmanned Aerial Vehicles (UAV) and satellite images. The combined use of images with different scales has made it possible to locate many archaeological structures unknown to date (drainage systems, walls, circular crop marks and a possible dock). The Sentinel-2 images, which were processed using principal components analysis and histogram equalization, show the river beds, flood-prone areas and several buried drainage channels surrounding the most important structures. The archaeological evidence obtained with the DTM and natural colour / multispectral images enables us to contrast a new dimension of land and water uses that goes beyond what was known to date. In the same way, these images enable us to understand in detail the environmental characteristics, land use, building distribution and flood defence structures of the Tiwanaku culture throughout its history, within the context of the environmental conditions of the Bolivian altiplano. This investigation allowed collection of new information and posed questions on the relationship of this site with water, as well as a better understanding of the extent and habitat features of this historical population