Multi-spectral imaging & thermal-decay mapping on sands and gravel bearing sub-soils

 LRC Project EH3841 funded by English  Heritage from the Aggregates Levy Sustainability Fund

Project Summary 

The light and well-drained sands and gravels, which provide a fundamental raw material for the modern building industry, provided the ideal location for early settlement and agriculture. River terraces and deposits on the margins of drainage basins such as the Vale of Pickering have been the setting for accidental discovery and or widespread destruction of archaeological evidence on countless occasions in the past. In order to reduce the accidental loss of important evidence of human occupation we need to adopt pro-active methods to identify and assess the archaeological resource so that a more sustainable approach to mineral extraction can be established.

Air photography and ground based geophysical survey have contributed an immense amount of information regarding past activity in the landscape. The results that can be gained from any particular technique vary according to the nature of the soils such that a geophysical survey in one area will identify most features whereas in others features fail to show. Conventional air-photography relies on short life crop-marks which also show differentially according to the soils.

This project using multi-spectral digital imaging (MSS) and Lidar surface modelling data, collected as part of a National Environment Research Council (NERC) award to Dominic Powlesland (Landscape Research Centre) and Dr. Danny Donoghue (University of Durham, department of Geography), will investigate the potential benefits of MSS, air-photographic and geophysical survey over two different sand and gravel deposits in the Vale of Pickering, North Yorkshire. Set against a background of more than 25 years of research within the area, undertaken on behalf of English Heritage, the project will draw upon air photographic, MSS data collected in 1994, and geophysical survey data integrated within an interactive Geographic Data Management System (GDMS) and compare and contrast the results of these and new MSS survey techniques. The new MSS survey will include imagery collected both during the day and at night, which can be used to create images reflecting thermal decay and variations in crop canopy moisture that are not visible to the eye.

Although the project will contribute to the archaeological landscape record of the Vale of Pickering, its principal contribution will be to develop a strategic understanding of the potential of MSS survey, linked to Lidar surface modelling data, for the rapid assessment of large areas of aggregate bearing geologies. By comparing and contrasting different techniques over different soils we hope to identify the most efficient methods for rapid assessment and landscape comprehension that can help inform future planning strategies in this type of landscape.

The project is designed to take place over a two year period, the latter part of which is concerned with technology transfer and training. Project outputs include not only publications on paper and on the Web but also training materials with distributed data sets which illustrate the methods and potentials of the various approaches to remote sensing. These training materials are intended to assist archaeological planners as well as other professionals in developing an understanding of the potential role of the new techniques in particular.