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High-resolution airborne lidar has been employed in the Maya lowlands to examine landscape modifications, detect architectural features, and expedite and expand upon traditional settlement surveys. Another potentially beneficial-and to-date underutilized-application of lidar is in the analysis of water management features such as small reservoirs and household storage tanks. The urban center of Yaxnohcah, located within the Central Karstic Uplands of the Yucatan Peninsula, provides an ideal test case for studying how the residents of this important Maya community managed their seasonally scarce water resources at the household scale. We employ an integrative approach combining lidar-based GIS analysis of 24 km 2 of the site area, ground verification, and excavation data from five small depressions to determine their function and the role they may have played in water management activities. Our research shows that some, but not all, small depressions proximate to residential structures functioned as either natural or human-made storage tanks and were likely an adaptive component of expanding Middle Preclassic to Classic period urbanization at the site. Thus, while lidar has revolutionized the identification of topographical features and hydrologic patterns in the landscape, a combination of ground verification and archaeological testing remains necessary to confirm and evaluate these features as potential water reservoirs.

Coba represents a major Classic period Maya urban center. Archaeological investigations have suggested a complex socioeconomic integration apparent in the heterogeneity of the size, shape, and quality of architecture while demonstrating a clear demarcation between commoner and elite compounds in addition to a complex system of raised roads (sacbeob). Results of the 1974-1976 mapping efforts at Coba revealed a generalized concentric settlement pattern with elite compounds concentrated at the core. In their analysis of the settlement patterns at Tikal, Guatemala, Arnold and Ford challenged this concentric model. Their analysis of labor investment in structures within the 9 km 2 core area of Tikal suggested, in contrast to Coba, a scattered rather than a concentric pattern of high-status architecture. Using a geographic information system (GIS), we tested our concentric model hypothesis for Coba by applying Arnold and Ford's work investment parameters. Our results confirmed the presence of a concentric pattern of high-status architecture at Coba closest to the core that differed from Arnold and Ford's findings of a scattered pattern in Tikal. These unique and discrete findings suggest that all major cities in the Maya area may not possess identical settlement patterns. To support our findings indicating urbanism, we also make a detailed analysis of the Coba and Calakmul demographics focusing on the Late Classic period.

This study proposes a sampling method for ground-truthing LiDAR-derived data that will allow researchers to verify or predict the accuracy of results over a large area. Our case study is focused on a 24 km2area centered on the site of Yaxnohcah in the Yucatan Peninsula. This area is characterized by a variety of dense tropical rainforest and wetland vegetation zones with limited road and trail access. Twenty-one 100 x 100 m blocks were selected for study, which included examples of several different vegetation zones. A pedestrian survey of transects through the blocks was conducted, recording two types of errors. Type 1 errors consist of cultural features that are identified in the field, but are not seen in the digital elevation model (DEM) or digital surface model (DSM). Type 2 errors consist of features that appear to be cultural when viewed on the DEM or DSM, but are caused by different vegetative features. Concurrently, we conducted an extensive vegetation survey of each block, identifying major species present and heights of stories. The results demonstrate that the lidar survey data are extremely reliable and a sample can be used to assess data accuracy, fidelity, and confidence over a larger area.

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