Recent landscape evolution of the Rio Grande drainage basin and impacts on the Nasca lines
Channel: Recording Archaeology
Date: 03/11/2015

Recent landscape evolution of the Rio Grande drainage basin and impacts on the UNESCO World Heritage List of the Nasca lines and geoglyphs (Peru)

Francesca Cigna1, Deodato Tapete2, Nicola Masini3, Rosa Lasaponara4
1BRITISH GEOLOGICAL SURVEY, 2DEPARTMENT OF GEOGRAPHY, INSTITUTE OF HAZARD, RISK AND RESILIENCE (IHRR),
DURHAM UNIVERSITY, 3INSTITUTE FOR ARCHAEOLOGICAL AND MONUMENTAL HERITAGE (IBAM), NATIONAL RESEARCH
COUNCIL (CNR), 4INSTITUTE OF METHODOLOGIES FOR ENVIRONMENTAL ANALYSIS (IMAA), NATIONAL RESEARCH COUNCIL
(CNR)


The arid Peruvian coastal plain, where the Nasca Civilization flourished between 200 BC and 600 AD, has a long history of landscape changes and alterations induced by not only human action and modern urban activities along the riverbeds of the Rio Grande drainage basin, but also environmental factors and natural land processes. Although erosion by flowing water seems of minor concern, the susceptibility to natural hazards such as flash floods and run-off of sandy materials from the Andean foothills persists for the fragile archaeological heritage of the UNESCO World Heritage List (WHL) site of the Nasca lines and geoglyphs. The potential risk to this heritage is also exacerbated by the effects of climate change, e.g. variations in the regional precipitation regime. Our research analyses satellite radar imagery depicting the WHL site over the last 20 years and aims to map landscape changes from the regional scale, looking at the whole drainage basin, to the local scale, focussing on river valleys of the tributaries Rios Ingenio, Nazca and Taruga and studying the recent hydraulic regime of the puquios, i.e. the ancient waterways and sources of irrigation water. We use a variety of radar sensors, including those onboard the European ERS-1/2 and ENVISAT missions, and the German TerraSAR-X and TanDEM-X satellites. Analysis of satellite time series with feature extraction and change detection approaches allows improvement of our knowledge of archaeological features, identification of surface indicators of environmental changes in such a dynamic region, and their correlation with climate pressure.