A GIS AND REMOTE SENSING METHOD, USING MODERN CLIMATE AND TOPOGRAPHY DATA, TO RECONSTRUCT PALEOHYDROGRAPHY

A geographic information system (GIS), in conjunction with remotely sensed imagery can be used to reconstruct late Quaternary and early Holocene paleohydrography. The relative ease and rapidity with which high-resolution, quantitative, and georeferenced data can be manipulated over a broad area makes the GIS method extremely useful. Our model uses three steps. First, drainage networks are interpolated from a digital elevation model (DEM) based on modern elevation and climate data. Paleodrainage basins are interpolated from the modern elevations and inferred reconstructions of climate and dated Pleistocene-Early Holocene lake elevations.

Second, precipitation and temperature maps were generated from modern topography and climate data. Ancient maps were generated by extrapolating temperature and climate data from previous paleoclimate studies using an elevation/precipitation correlation. Both modern and ancient maps can be used to estimate precipitation, evaporation and runoff over an entire study area. Third, the runoff is inferred using a precipitation/runoff model. For this example, we borrowed the concept of an elevation/precipitation correlation used in the PRISM model (Parameter-elevation Regressions on Independent Slopes Model of Daly et al., 1994). As an example, we created a Paleohydrogeographic model of the Latest Pleistocene/Holocene pluvial lakes of the southeastern Basin and Range province, in New Mexico, Texas, and Mexico.

Paleohydrogeographic databases can be used for many purposes, including the generation of paleo-topographic base maps, the estimation of drainage areas and volumes of individual water bodies and landforms, and the approximation of paleo-shoreline positions. GIS-based estimates of the location of surface water features and the dimensions of water bodies and associated landforms can be used to help constrain hydrological and climatic models of the late Quaternary and early Holocene.