Geography
Degradation of Cultural Heritage
Mapping and Monitoring of Weathering Forms
Measurement and Analysis of Erosion Rates
Weathering Research at Portsmouth
Research in weathering involves the study of the degradation of cultural heritage, the mapping and monitoring of weathering forms, the measurement and analysis of erosion rates and the philosophical consideration of weathering as part of the landscape system. Within each of these topic areas the significance and role of weathering for issues such as climate change and sustainable conservation are considered. The research is carried out by Rob Inkpen and Derek Mottershead in the Department of Geography and in collaboration with colleagues within the University and at other universities, conservation centres and historic monuments.
Degradation of Cultural Heritage
Research into the processes and rates of degradation of cultural heritage involves the monitoring and detailed analysis of culturally sensitive materials. Laboratory based analysis of weathering processes such as salt weathering and freeze-thaw using controlled environmental conditions (FISONS environmental cabinet) are supplemented by detailed examination of degradation on monuments in the field.
Detailed analysis of surface form using a laser scanner and close-range photogrammetry enable a close examination of process-form relationships at a micro-scale both in experimental work and in field monitoring.
Funded work on biological degradation (BIOBRUSH) have enabled the identification of damaging bacteria, such as sulphur generating bacteria, as well as potential remedial treatments using calcifying bacteria. Central to these studies has been a clear understanding of how biotic agents affect the surface properties of culturally sensitive materials and the need for careful and accurate monitoring of their impacts.
This work has been recently extended to the monitoring and development of biological treatments for the removal of algal biofilms from the surface of Portland limestone gravestones used by the Commonwealth War Graves Commission (CWGC).
Illustrative publications
Inkpen, R.J., Collier, P. and Fontana, D.J.L. 2000. Close-range photogrammetric analysis of rock surfaces. Zeitschrift fur Geomorphologie, 120, 67-81.
Inkpen, R.J., Collier, P. and Fontana, D.J.L. 2001. Mapping decay: Integrating scales of weathering within a GIS. Earth Surface Processes and Landforms, 26, 885-900.
Mottershead, D.N.B, Baily, B, Collier, P. and Inkpen, R.J. 2003. Identification and quantification of weathering by plant roots. Building and Environment, 38, 1235-1241.
Mapping and Monitoring of Weathering Forms
The identification, mapping, monitoring and quantification of changes in weathering forms are essential aspects of caring for our cultural heritage. Research at Portsmouth has focused on developing an integrated database and GIS methodology (funded by the Foundation for the Built Environment, FBE) for establishing baseline information on degradation as well as providing a framework for long-term monitoring.
Contemporary photographic and photogrammetric recording of buildings is used with historic imagery to develop a database of changes in degradation forms and rates. Additional use of laser scanning equipment can supplement the impressions of the imagery with information about degradation at the micro-scale.
Illustrative publication
Inkpen, R.J., Duane, W., Yates, T. and Burnett, J. (in press) Integrated database and GIS for analysing contemporary and historic weathering on buildings. Building and Environment
Measurement and Analysis of Erosion Rates
Measurement of erosion rates using standard contact methods such as the micro-erosion meter (MEM) and non-contact methods such as close-range photogrammetry and laser scanning provide the basis for the analysis of changes in rock surfaces.
Erosion rates from points can be used to establish patterns of change in time and across space in response to environmental and geological characteristics. This enables the impact of environmental changes such as reduced pollution levels to be assessed.
Statistical analysis of MEM data from shore platforms (with Wayne Stephenson, Melbourne) has been used to assess if such point data provides an adequate representation of the alteration of the whole surface. Extending this analysis, the differential response of different surfaces can be modelled.
Illustrative publications
Trudgill, S. T., Viles, H. A., Inkpen, R. J., Moses, C., Gosling, W., Yates, T., Collier, P., Smith, D. I. and Cooke, R. U. 2001. Twenty years weathering re-measurements at St Paul's Cathedral, London. Earth Surface Processes and Landforms, 26, 1129-1142.
Inkpen, R.J., Twigg, L. and Stephenson, W.J. 2004. The use of multilevel modeling in evaluating controls on erosion rates on inter-tidal shore platforms, Kaikoura Peninsula, South Island, New Zealand. Geomorphology, 57, 29-39.
Inkpen, R.J. and Stephenson, W.J. 2006. Statistical analysis of the significance of site topography and erosion history on erosion rates on intertidal shore platforms, Kaikoura Peninsula, South Island, New Zealand. Geomorphology, 81, 18-28.
Inkpen, R.J. (in press) Interpretation of erosion rates on rock surfaces. Area.
Weathering and Landscapes
The nature and rates of weathering and erosion are important conceptual issues in landscape development. Analysis of weathering and erosion at relatively short spatial and temporal scales can provide a useful analogy for long-term landscape development and pose many interesting questions concerning landscape evolution.
Such issues have been explored at a salt rock site in Cardona where landscape change has been measured using a scanning total station over a period of years. In addition, consideration of scales of weathering aids in understanding how links can be established (or not) across scales in terms of process, forms and explanatory frameworks.
Illustrative publications
Inkpen, R.J. and Petley, D. 2001. Fitness spaces and their potential for visualising change in the physical landscape. Area, 33, 242-251.
Inkpen, R.J. 2004. Weathering scales, landscapes and change: some thoughts on links. In Stone Decay: Its Causes and Controls, Smith, B.J. and Turkington, A.V. (eds.) Donhead, Shaftesbury. 292-306.
Mottershead, D.N., Wright, J.S., Inkpen, R.J. and Duane, W. (in press). Bedrock slope evolution in saltrock terrain. Zeitschrift fur Geomorphologie.
Mottershead, D.N., Duane, W.J., Inkpen, R.J. and Wright, J.S. (in press). An investigation of the geometric controls on the morphological evolution of small-scale salt terrains, Cardona, Spain. Environmental Geology.