Landscapes of Death: GIS Modelling of a Dated Sequence of Prehistoric Cemeteries in Vastmanland, Sweden

Article excerpt

Introduction

The Malaren Valley in central Sweden (Figure 1) has had a long history of social analysis based on more than 10 000 prehistoric cemeteries, the remains of which are often visible above ground as mounds or monuments (e.g. Ambrosiani 1964; Hyenstrand 1974). The descriptions and locations of these cemeteries are recorded in the Swedish monuments record, which has now been digitised and made available online in both ESRI Shapefile and MapInfo TAB format by the Swedish National Heritage Agency (Riksantikvarieambetet), through FMIS, the information system for archaeological sites and monuments (Blomqvist & Gentay-Lindholm 2002; Haskiya 2002).

To make use of this information to map social change, it is necessary to establish a chronology for the burial grounds. An ambitious attempt in the late 1970s employed descriptions of the sites and their location in the landscape to suggest an estimated date of use (Gustavsson & Liden 1980). Since then there have been new surveys and a large number of rescue excavations. This suggests that it might be time for a new study, making use of the technology available today.

This article presents a renewed attempt at relating the location of cemeteries to their date, choosing the district of Vastmanland as a case study. In this study 1034 burial grounds and 3649 features registered as single graves were analysed using GIS and compared with the chronological information from excavated burial grounds in the same area. Variables were collected from both the monuments record, such as type and shape of the graves, as well as from the landscape, such as topographical features and soil type at each site. A statistical profile was thereby created and used to classify the burial grounds recorded by survey in relation to those that had been excavated.

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Although variables from the physical landscape were used for the analysis, the model was not seen as environmentally deterministic. Rather, it assumed a cognitive relation between the contemporary meaning of a burial and its position in the landscape. The result of this ought to be that burial location in the landscape varies significantly with time. Among the advantages of a statistical analysis is the possibility of identifying quantitative trends in burial location by period, and of including new information from future surveys and excavations, and so update and improve the model.

The database

FMIS has been available online since 2003, and today all of Sweden's provinces have had their records digitised and included in the database--at present over 1.7 million items in total (www.raa.se). However, this number may increase substantially in light of future excavations as, when a burial ground is excavated, it is common for only about 50 per cent of the graves identified during the excavation to have been known from previous surveys. As such, like any other archaeological record, the FMIS database carries ambiguities and uncertainties associated with surface features that are often vague, damaged or disintegrating. Hence, the use of this record is not straightforward, and the interpretations of the social landscape and settlement structures must take note of these caveats (Sawyer 1983; Bennett 1987).

The database for the province of Vastmanland contains 4683 sites amounting to 18 205 individual graves (Figure 2). The superficial appearance of each grave is described by up to three variables (broadly: overall type, construction and shape) (Table 1; Haskiya 2002). A combination of these variables results in 59 recurrent types of burial monument observed in the dataset.

The variables for each site were collected and aggregated from the database using the FME Workbench application (Lowenborg 2007). Of the 59 different types, some are very rare whilst the majority (67.3 per cent) belong to a single category: round, earth-filled stone-settings. …