CORONA Photographs in Monsoonal Semi‐arid Environments: Addressing Archaeological Surveys and Historic Landscape Dynamics over North Gujarat, India

Abstract

Here we illustrate a ground map approach that uses orthorectified CORONA KH4B images and declassified topographical maps to study historical land-use dynamics and to help planning archaeological survey in the monsoonal semi-arid alluvial plains of North Gujarat, India. In spite of its generalized use in archaeological applications, CORONA photographs have rarely been used in Indian archaeological contexts. The methods discuss a cost-effective and integrated protocol for: (i) obtaining ground control points (GCPs) and orthorectify CORONA photographs when very high-resolution imagery or detailed topographic maps are not available; and (ii) evaluating the integration of declassified datasets into Google Earth Pro for addressing archaeological surveys in remote areas. The merging of CORONA imagery with declassified USA and the former USSR historical military maps provided a picture of the human-environment interaction in North Gujarat of the past 40 years, prior to the intense development of mechanical agriculture and regional irrigation channels. We conclude by identifying the human and climate-induced taphonomical processes that are obliterating a fragile landscape characterized by archaeological scatters located in fossilized sand dunes.The land-use patterns that were earlier determined by the availability of surface water (stored in seasonal flooded interdunes or village ponds, in close relation

A ‘Reflexive’ Multi-Stage Survey Methodology for Historical Landscape Research in Central India:Field-Walking, Local Knowledge, and Satellite Imagery as Archaeological Site Prospection and Mapping Tools in the Sanchi Survey Project

“…Nevertheless, they are visually prominent features in the landscape, while hillside settlement detection was dependent on a combination of systematic exploration, as used recently, for example, to locate rock-art sites in South India 73 , local leads, and as discussed later, local traditions whereby sites with perceived antiquity are granted sacred status. Many previously identified mounds showed up easily in the highresolution Quickbird and Corona imagery due to their lighter hued, ceramic-rich soils; similar observations have been made in Gujarat 5 and Syria 74,75 . Mound identification was thus one of the few areas in which satellite imagery might have been a useful site-prospection tool during stage I.…”

“…Some commentaries 14,15 are particularly disparaging towards low-budget, small-scale projects, with others 10 questioning whether the low resolution they provide justifies the effort at all. Although many such problems have been remediated by the use of cheap handheld GPS technology, remote sensing and freely available satellite imagery such as Google Earth 4,5 , and while the detection of 'non-site' data is generally attributed to the development of systematic survey techniques 13,14,16 , it should be stressed, however, that developments in archaeological ethics and public archaeology have led to greater recognition of the veracity of the local voice 9 . For many parts of the Indian subcontinent, the detectability of broader 'non-site' categories such as 'associated landscape' data 17,18 , cult-spots or unpainted rock-shelters, is less dependent on 'advanced' reconnaissance technologies than on engagement with local traditions of ancestral memory, attachment to place and intergenerational identity.…”

“…Finally, restricted access to aerial photography and high-resolution maps was until recently a deterrent against intensive gridding methods 22 . Since 2006, various projects have capitalized on the availability of free satellite imagery such as Google Earth with varying aims and results [4][5][6] . In northwest India, the Rakhigarhi 53 and Ghaggar Hinterland Surveys 54 , through the use of remote sensing and GPS-based mapping enabled calibration of earlier village-to-village survey data 23,24 .…”

“…The 1969-70 Corona imagery, with a ground resolution of about 3 metres, was of particular interest as it reflected a landscape unaffected by the many modifications that have been brought about by subsequent construction, quarrying, tree-planting, canalization, mechanical ploughing and irrigation activity; similar assumptions have informed more recent survey-based investigations in Gujarat 5 . Overall, the KFA imagery was disappointing due to camera aberrations or atmospheric distortions.…”

“…Although the project was initiated in 1998, remote sensing was only introduced in 2003 as a means to aid mapping and to test a subset of imagery as a potential tool for archaeological prospection. This represented one of the earliest such attempts in South Asian archaeology, prior to the launch, in 2006, of freely available datasets such as Google Earth which has prompted several investigations of the relative pros and cons of such imagery [4][5][6] . Despite the obvious benefits of freely available satellite imagery for archaeology, and in particular low budget or public archaeology endeavours, in a region with otherwise restricted access to detailed mapping resources, the Google Earth imagery has its limitations as a primary siteprospection tool 7 .…”