Faculty Sponsor

Carl Lipo


High-resolution multispectral imagery provides an effective means for measuring the archaeological record of Rapa Nui. Previous work has suggested that the island’s prehistoric cultivation features known as “lithic mulch gardens” can be identified using near infrared imagery (NIR). Lithic mulching was a laborious but critical strategy for prehistoric populations who relied on cultivating sweet potato and taro in nutrient poor soils for their subsistence. The new WorldView-3 satellite offers researchers access to short-wave infrared (SWIR) bands, imagery that provides additional information about moisture content and mineral composition. While these bands should provide a better means for identifying lithic mulch gardens, this new imagery is currently only available at a lower spatial resolution than NIR images (7.5 m vs. 1.24 m). Here, I evaluate whether these lower-resolution SWIR images can be used for identifying “lithic mulch garden” features despite their resolution difference. Comparing the results of SWIR imagery with that of previous analyses reveals markedly similar classification accuracy despite having the lower spatial resolution. This result suggests that SWIR may provide a new tool for researchers interested in questions of prehistoric land-use that will become increasingly more powerful as greater spatial resolutions become available.