WATERSHED-SCALE HYDROGEOLOGIC ANALYSIS AND PALEOHYDROLOGIC MODELING OF PREHISTORIC SETTLEMENTS IN THE CANYON OF THE ANCIENTS REGION, SOUTHWEST COLORADO: A HIERARCHICAL APPROACH USING GEOLOGY, HYDROLOGY, GEOMORPHOLOGY, AND MATHEMATICAL MODELING

The purpose of this NSF biocomplexity study is to model the paleohydrology for human settlement systems in the Canyon of the Ancients Region, Colorado and Utah. Specifically, our intent is to understand and model the lagged response of the water resources in our study area to changes in climate and impact of human occupation by understanding and modeling the modern hydrologic systems, and by studying and modeling coupled human/natural landscapes and hydrologic systems over very long periods of time.

The broad hypothesis is that changing distributions of water sources, including flow quantities, during the late pre-Hispanic occupation affected the settlement systems and significantly contributed to the depopulation of the area. In this context, the approach is to: 1) conceptualize and characterize the modern hydrologic system, using the integrated, multidisciplinary hierarchical systems analysis of Kolm et. al. (1993, 1999, 2000); 2) develop solid and mathematical models to visualize and quantify the modern hydrogeology and hydrologic system on a watershed-scale; 3) test the mathematical models by incorporating known hydrologic system stresses that have occurred within historic times; and 4) develop scenarios of the paleohydrologic system based on paleoclimate records, using tree ring data and paleo jet stream analysis for identifying the relative roles of climate and human-induced stresses. This paper will present the progress to date of the conceptual model of the modern hydrologic system of southwest Colorado based on the characterization of the hydrologic system, the hydrogeologic solid block model, and the mathematical flow model.