Culture and Ecology of Chaco Canyon and the San Juan Basin

- - ----- -------------------------- --12 Chaco Project Synthesisfeatures allowed investigators to measure volumes andwall thicknesses, to add and subtract walls to createmaps of different construction stages, and to printmaps at any point during these manipulations (Dragerand Lyons 1985; Pouls et aI. 1976).Are these methods cost-effective? Ireland (1980)reported that for small sites the traditional methods areuseful and cost-effective, but when a site is large ormore than one site is to be mapped, photogrammetricor photo-interpretive mapping should be considered.Other /11Ulgery and Sensors. Experimentswith other imagery obtained above ground werecarried out. Loose (1976a) found that airborne taperecording provided excellent color imagery, but thatfilm resolution was not as good as that obtained fromaerial photographs. Data from a Bendix M 2 S multiscannerflown approximately 457 m (1,500 ft) aboveground over five pueblos in Chaco Canyon showedpromise in detecting agricultural fields, structures, andlinear alignments (Morain et aI. 1981). Satelliteimagery (ERTS and LANDSAT) provided repeatedbeam video and multispectral scans at several scales,including 1:250,OOO--the size of USGS topographicmaps. Depending on the scans combined into a composite,false color infrared or black-and-white imagescould be obtained and computer enhanced (Drager1983b). Schalk and Lyons (1976) stratified the SanJuan Basin into gross ecological zones, and determinedthat a clear division between the northeastern andsouthwestern parts of the basin existed. ChacoCanyon is an erosional feature situated on the contactof two ecotones; the resources in each one suggestedenvironmental determinants of settlement patterns thatmight be observed from such imagery. Vegetativecover type for the San Juan Basin (Camilli 1983;Drager 1983a) was plotted (Drager and Livingston1983) and compared with geology and precipitationmaps (Ireland 1983), and soils (Ireland and Drager1983) at the same scales as aides in predictingarchaeological site densities for unsurveyed areaswithin a study area (Drager 1983b; Drager and Ireland1983).One ethnographic study by Fanale (1982) usedboth LANDSAT and aerial photography to facilitateresearch on late-nineteenth- and early-twentiethcenturyNavajo land use in the San Juan Basin.Acetate overlays of 31 areas were prepared usingLANDSAT imagery. Cover type, land formations,vegetative associations, soil types, and rainfallpatterns were noted. This method quickly provideduseful information about the environment of each ofthe study areas (Fanale 1982:75-79). Armed withmaps depicting settlement features, legal land tenureinformation, and other information, as well as aerialphotographs, Fanale was able to quickly locatehousehold units and preplan routes to sites that wereoften difficult to find in open areas of the basin.During interviews, informants could mark places theyhad lived, zones used for herds, and mobility routes(Fanale 1982: 84-85).Three sensors that detect anomalies under groundwere evaluated. Refractive seismology was used toprobe the surface beneath the canyon floor todetermine depth to bedrock (Lewis and Shipman 1972;Ross 1978). However, transects across site 29SJ633by Phil Bandy (1980) were disappointing. Jacobson(1979; in Mathien 1991a:351) found that none of thepatterns could be interpreted as features. Protonmagnetometer measurements at 29SJ633 and PuebloAlto did detect a number of features (Bennett andWeymouth 1981, 1987:MF-29; Jacobson 1979; inMathien 1991a:353). Tests with subsurface radardetected masonry walls but not adobe walls (Vickersand Dolphin 1975; Vickers et al. 1976). Since theseexperiments were conducted, many improvementshave been made in equipment to provide better results.In conclusion, as Giardino and Thomas (2002)indicate that "By the early 1980's, there weresufficient accomplishments in the application ofremote sensing to anthropology and archaeology thata chapter on the subject was included in fundamentalremote sensing references (Ebert and Lyons 1983)."Many of these techniques have been further refinedand are now accepted practices in North America andEurope (Kvamme 2003). The remote sensing stafffulfilled the goals set forth in the Chaco Prospectus totest this new suite of sensors, as well as contributed tothe cultural research program (contributions areincluded in the remaining chapters as appropriate).Survey TechniquesPrevious site surveys either focused on Pueblosi tes along the bottom of the canyon (Pierson 1949) orwere limited to a specific area that included land