Monitoring Emerging Archaeological Sites Using Multitemporal NDWI - Case Studies from Iraq.

Abstract

Among the many threats that archaeological sites are subject to in the Middle East and North Africa (MENA) region, dam construction and artificial lakes formation have been some of the most common since the last 50 years. Notwithstanding past archaeological surveys and salvage excavations in threatened areas, the formation of artificial reservoirs often results in the permanent loss of archaeological data. However, recent evidence from the Mosul dam lake has shown that a sharp fall of the water level due to climatic events or dam management, could lead to the emerging of some archaeological sites from the water, allowing for their brief and targeted investigation. Reservoir water level change is not unique to the Mosul dam, but it is a phenomenon affecting most of the artificial lakes of present-day Iraq. However, to know in advance which sites will be affected by the retraction of reservoirs can be a difficult task, especially without field investigation or high-resolution satellite images. The present paper will try to monitor “patterns” of emerging archaeological sites in the Mosul, Haditha and Hamrin lakes using multitemporal medium-resolution satellite images, combined to obtain spectral indexes for different years. The Normalized Difference Water Index (NDWI) is suitable for differentiating between water bodies and other land surfaces, and together with a pixel analysis of Landsat and Sentinel-2 images it can provide a mean for highlighting whether an archaeological site is submerged or not. The results from this analysis will then be evaluated using high-resolution images for specific years and locations, as indicated by remote sensing. Understanding emersion “patterns” of known archaeological sites can provide a useful tool for targeted rescue excavation, possibly expanding the knowledge on the archaeological record of the regions under study.

Andrea Titolo

Research Fellow

My research interests include Settlement Pattern Analysis, Remote Sensing, GIS, and mapping.