Reconstructing past landscapes
Data collected from geophysical and geotechnical surveys and that obtained from geoarchaeological and environmental analyses was synthesised to allow for the reconstruction of the palaeo-Arun prehistoric landscape, as described below. To find out more about the survey methods and analyses employed, click here.
The seismic data from the geophysical surveys was used to create a 3D model of the submerged landscapes of the study areas, detailing the palaeovalleys and other topographical features. The seismic data was processed using a program called Coda Geosurvey. Coda Geosurvey allows an interpretation to be applied to a line of data by identifying and selecting boundaries between layers. After interpretation, the program can output the data in x ,y ,z format, essentially the data has an x-axis and y-axis to reflect its geographical position and a z-axis to illustrate its depth. The data collected during the 2003 – 2004 season was also processed with Geoframe and Promax software programs, these are more sophisticated programs more commonly used for interpreting more complex data sets from surveys for the oil and gas industries.
After processing and interpretation, data was then modelled using a program called Fledermaus. Fledermaus is a 3D-visualisation and analysis software package. This software can create 3D solid surfaces for any set of data containing points with an x, y and z value. These surfaces are made by gridding the data shading the surface with a user selected colour file so that the colours represent the relative heights over the surface. This 3D surface can then be explored and visualized. As these surfaces are best studied in 3D it can be difficult to get all the information they display onto a flat image, therefore Fledermaus allows profiles across these surfaces to be made to help show some of the vertical information.
Click here to view a 3D model of the palaeolandscape identified in the 2003 - 2004 season.
The computerised reconstruction of the palaeo-Arun landscape was created by integrating data collected from geophysical and geotechnical survey to provide a basis for interrogation of the landscape during the early Mesolithic period.
The topographical data from geophysical surveys was exported as a digital elevation model (DEM). The DEM was then exported to a greyscale image which was imported into Vue, a computer imaging program. The height and horizontal scales of the terrain were then accordingly calibrated to model the geography of the area.
In order to add the vegetation, the landscape was divided into five ecozones. These were broadly decided upon using height and hydrology and the information on the potential ecology derived from environmental data. It was predicted that the upper drier areas (shown in red) supported a mixed hazel, oak, and pine woodland. A marshland/saltmarsh habitat was ascribed to the lower area (shown in blue-yellow), and fringing this (shown in green) was a mixed hazel, birch, willow and aspen woodland. The landscape was extended to incorporate an area of 3km by 3km. This was done to take in the peripheral views seen by the camera.
Composite photographs of real-world ground textures, sand, woodland floors, grasses etc. were used to cover the terrain used for each ecozone. For each ecozone a separate terrain model was used so that vegetation and ground textures could be added more easily. Rather than adding individual trees they were added using a function in Vue that allows a landscape to be populated with varying proportions of individual species.
For scarcer species such as pine, willows, birches, and woodland shrubs, blackthorn, and dogwood, models from virtual libraries in a program called Greenworks XFrog were chosen. XFrog gives the user complete control over these virtual plants, allowing features, such as age and trunk thickness to be altered. Individual trees, shrubs, herbs and grasses were also modelled in Vue. Real photographs of bark, lichens, mosses, stems and leaves were used for the models.
People and animals were added using Poser to suggest occupation of the area. Evidence from known Mesolithic archaeological sites was used as the basis for these elements. The people are shown fishing and gathering, activities known from the archaeological record. Similarly, the animals featured are well represented in the archaeological record for the Mesolithic period.
The data provided a spatial context to the landscape and the integration and forensic interrogation of that scientific and cultural data (i.e. palaeotopography, palaeoenvironmental, vegetation, archaeological and cultural) by archaeologists and palaeoenvironmentalists enabled the visualisation of the prehistoric landscape, vegetation, ecology and human action and activity.
View the Seabed Prehistory 3D visualisation.