Switching to Digital Tools: heritage evaluation for preventive archaeology in Hungary

During the last decade in Hungary, preliminary operations for large-scale archaeological excavations have became more and more important: the stakeholders have realised that it is cost-effective to spend more on the assessment phase rather than incurring higher expenditure because of problems related to an ill-planned project. Thorough knowledge of the size and characteristics of archaeological sites can largely contribute to the protection of the cultural heritage, as well as saving time and money.

From 2011 Preliminary Archaeological Evaluations have been a mandatory part of the permission process of large-scale constructions (that is to say, a total minimum cost of c.1,600,000 EUR). These evaluations consist of desktop studies (such as analyses of historical documents and maps), as well as field investigations with a budget of 0.35% of the total construction cost. The goal is to make precise archaeological project plans, and to assess the optimal mitigation process.

The Forster Centre – and its predecessor – has been responsible for the coordination and execution of preventive archaeological evaluations since 2013. During that time we have established and tested a GIS-based method which has been effective in large-scale investments and which – due to financial constraints – relies greatly on non-invasive methods as tools to help our investigation strategies.

Our current strategy relies on three interdependent tasks: GIS-based field surveys, large-scale magnetometer surveys and targeted trial excavations. The scale of our tasks is challenging and demanding at the same time: the investigation of large areas with various methods gives us substantial and reliable datasets on the archaeological landscape. Collecting and comparing these GIS-based datasets on a nationwide scale gives us an opportunity to determine the most effective methods to identify and protect the archaeological heritage. One of the most promising opportunities is to create a comparative database, where the outcomes of geophysical surveys and excavations from hundreds of hectares are available across the country. Using the results, we can set up a comprehensive archaeological geophysics database that would facilitate making our magnetic prospections more accurate and our methods more targeted.

This extended abstract is also available in hard copy in K. May (ed) 2017 Digital Archaeological Heritage, EAC Occasional Paper No.12, Archaeolingua, Budapest.

During the last decade in Hungary, preliminary operations for large-scale archaeological excavations have became more and more important: the stakeholders have realised that it is cost-effective to spend more on the assessment phase rather than incurring higher expenditure because of problems related to an ill-planned project. Thorough knowledge of the size and characteristics of archaeological sites can largely contribute to the protection of cultural heritage, as well as to saving time and money. From 2011, the so called 'Preliminary Archaeological Evaluations’ have been made a mandatory part of the permission process of large-scale constructions (that is to say, a total minimum of c.1,600,000 EUR). These evaluations consist of desktop studies as well as field investigations with a budget of up to 0,35% of the total construction cost. The goal is to make precise archaeological project plans, and to assess the optimal mitigation process. These documentations consist of the establishment of the actual area to be excavated, as well as the cost and duration of the archaeological mitigation process. The funding of further archaeological activities is based on these evaluations, which renders them one of the cornerstones of preventive archaeological activities in Hungary.

The Forster Centre – and its predecessor – has been responsible for the coordination and execution of preventive archaeological evaluations since 2013. The Forster Centre is a government office acting as an independent third party between the investors and the institutions responsible for further archaeological mitigation processes following the evaluations. In recent years, we introduced and tested a GIS-based method that we found effective in large-scale investments and which – due to financial constraints – relies greatly on non-invasive methods as tools to help our investigation strategies.

Our current strategy relies on three interdependent tasks: GIS-based field surveys, large-scale magnetometer surveys and targeted trial excavations. The first step is always a desktop study and a full-scale systematic field survey over the whole area of interest in order to collect archaeological materials and identify sites and features. The next step sees magnetometer surveys performed within these areas – including areas with no surface finds but with a high potential for archaeological features – in order to identify actual archaeological areas. As the third step, the previously collected data are validated through trial excavations. Funding is usually very limited, thus the trenches are laid out based on the results of the field survey and magnetic prospection either to validate archaeological features or confirm the lack of them. The current legislation also limits the extent of trial excavations at archaeological sites in development areas. Obviously, this approach is based on surface finds, and therefore has a restricted potential regarding archaeological features invisible during field surveys. Nevertheless, considering limited financial resources, we must focus on areas where the presence of archaeological features can be confirmed. In general, at least 30-40% of the entire project area is covered by magnetometry survey. If needed, we also can carry out supplementary surveys such as coring, aerial archaeology or GPR survey.

The scale of our tasks is challenging and demanding at the same time: the investigation of large areas with various methods gives us substantial and reliable data on the archaeological landscape. The greatest strengh of this approach is the integrated use of magnetometry for preventive archaeological tasks. In the recent past geophysical surveys were mostly used as a scientific attribution in Hungary, scarcely used in the decision-making process. However, geophysical investigations should be integrated into regular site identification strategies of preventive archaeology whenever possible in order to be used to its fullest potential and to make useful predictions. The archaeologists responsible for excavations should be provided with support in order to understand and use these data during the planning phase.

Accumulating and comparing GIS-based information on a nationwide scale gives us an opportunity to examine the methods most effective in identifying and saving archaeological heritage. One of the most promising opportunities is to create a comparative database, where the outcomes of geophysical surveys and excavations from hundreds of hectars are available across the country. The option to survey across very different areas and validate it with trial trenching is a very powerful tool to understand the impact on and advantage of magnetic survey in archaeological heritage management. Beginning in 2013, magnetometric surveys have been carried out for more than one hundred projects, and included 360 archaeological sites, measuring an approximate total of 500 hectares. Using the results, we can set up a comprehensive archaeological geophysics database that would facilitate making our magnetic prospections more accurate and our methods more targeted. By comparing the results of magnetometer surveys and excavations, we estimate an overall predictability of 80 per cent of features (for true positive and true negative values) during our prospections. If we could further evaluate the data derived from this constantly growing dataset, it could serve as a strong argument to persuade stakeholders to utilise these analytical methods more systematically, giving the archaeologists more chances to obtain information about the affected archaeological sites and making the mitigation process more effective.