1. Dataset location

The dataset has been deposited in the Repository of the University of Ljubljana, PID: 20.500.12556/RUL-160103

2. Dataset Content

This dataset consists of slope classification results for the entire country of Slovenia and data on extensive and intensive survey results at 24 case study sites along with excavated areas at the sites. Specifically, the data includes:

• 100m resolution digital elevation model (DEM) of Slovenia resampled to 25m (1 tiff file).
• Slope classification results based on the resampled DEM (4 shapefiles).
• Slope classification results based on 25m resolution DEM (4 shapefiles).
• Slope classification results based on 25m resolution DEM of Slovenia (4 shapefiles).
• Extensive survey results (24 shapefiles with attribute tables), intensive survey results (22 shapefiles with attribute tables) and excavated areas (61 shapefiles) at 24 case study sites.

3. Background to the dataset

The survey results included in the dataset were first acquired during fieldwork carried out between 1994 and 2009 as part of the Slovenian motorway project, the largest development project in Slovenia to date (see Djurić 2003; Gruškovnjak 2024). Surface and subsurface field surveys were the main discovery methods used to detect unknown archaeological sites suspected within the development area. The surface survey was applied to unvegetated cultivated areas, and the subsurface survey to vegetated uncultivated areas. The survey was carried out in two phases, extensive and intensive.

The extensive phase (Fig. 1), covering the entire development area, was conducted in transects 50 m long and spaced 10 m apart (Fig. 2). The surface survey involved walking along the transects and collecting all detected surface cultural material. The subsurface method involved digging a single 40×40×40 cm test pit at each transect and collecting the material within it.

As potential archaeological sites, the areas with positive results were subjected to an intensive survey phase using a grid of 10×10 m quadrants (Fig. 2). The surface survey inspected the entire surface of each quadrant, while in the case of the subsurface survey, a test pit was excavated in each. Based on intensive survey results, the presence of archaeological sites was either confirmed or refuted (Djurić 2003 , 16-18).

Archaeological excavations (Fig. 2) followed at all confirmed sites to the extent determined by the distributions of discovered finds (Djurić 2003 , 18). Archaeological monitoring was carried out during construction at unconfirmed sites and some larger tracts of the development area.

The fieldwork results were compiled and digitized in a Geographic Information System (GIS) environment as part of a PhD research project conducted by the author (e.g. Figs. 1-2). The dataset presented here represents a selection of the data used to evaluate the influence of geomorphic processes on survey results and underlies a paper published on the topic (Gruškovnjak 2024).

4. Summary description

The dataset is a filtered, partly reproducible, and partly non-reproducible dataset (see Štular 2021) consisting of reproducible relief analysis results and a selection of non-reproducible field survey and excavation results. The relief analysis was used to classify the entire surface of Slovenia according to the five slope elements model (see e.g. Schaetzl and Anderson 2005 , 477-484; Gruškovnjak 2022 ; 2024). The classification using Relief Analysis Toolbox for GIS (Miller 2014; Miller and Schaetzl 2015) was conducted on a 100m resolution DEM, which was resampled to 25m to achieve a smoother visual result, and on a 25m resolution DEM, both available at the Open Data of Slovenia portal. The slope classification results achieved on the resampled 100m DEM, used in the related paper (Gruškovnjak 2024), are relevant for archaeological data concerning the Slovenian motorway project as they reflect land surface conditions before the motorway construction. The finer scale results achieved on the 25m (Fig. 3), on the other hand, include surface reworking due to motorway construction and are more relevant for areas outside the development area. They were added to the database after the related paper publication because of their additional reuse potential.

The survey results included in the dataset concern 24 case study sites (Fig. 1) used to explore the effects different slope positions and related geomorphic processes have on the effectiveness of site discovery and the relationship between the topsoil and the subsurface archaeological records. The selection of the sites was, on the one hand, based on the availability of sufficient data for exploring these research questions and, on the other hand, focused on non-stable geomorphic surfaces of backslopes, footslopes, and toeslopes. The data for each case study site is composed of three different sets, corresponding to the three stages of fieldwork. The first set provides the results of the extensive survey, the second provides the results of the intensive survey, and the third provides the extent of the excavated area at each site (Fig. 2). Details on the database structure are provided in the Readme document accompanying the database.

5. Scope

Along with slope classification results for the entire Slovenia (Fig. 3), the dataset provides a selection of survey results from the Slovenian motorway project (Fig. 1) based on the criteria outlined above. Therefore, it is not a comprehensive dataset of all survey results from the project. The extensive survey data provided here represent extracts of the surveyed areas surrounding the case study sites, while the intensive survey results at the sites are complete. When case study sites in the database are missing intensive survey results, it is because they were not surveyed in the intensive phase.

6. Re-use potential

The dataset enables validation of results reported in the related paper (Gruškovnjak 2024) and could facilitate more detailed comparisons of extensive and intensive survey results and excavation results that go beyond the scope of the paper.

The main re-use potential envisioned for this database, however, lies in the slope classification results. Combining them with pedological and topographic maps and following the approach outlined in Gruškovnjak (2024) they can be used to assess the potential impact of geomorphic processes on the archaeological record anywhere in Slovenia. This should be done as the first step before any archaeological field research, especially to establish whether surface, near-surface or buried sites are expected and determine the most suitable prospection methods for detecting or exploring sites. This approach should, for example, guide cultural resource management decision-makers in Slovenia in prescribing preliminary archaeological investigation methods.

7. Relationship to archives and publications

This dataset underlies both Gruškovnjak 2024 and partly Gruškovnjak 2022.

The dataset draws on the original fieldwork documentation, digital data and unpublished reports held by the Institute for the Protection of Cultural Heritage of Slovenia (IPCHS) and its Centre for Preventive Archaeology. It also draws on or is related to the following published excavation results at case study sites:

1. Kračine: Tušek and Kavur 2012
2. Cogetinci: Horvat 2013
3. Brengova: Janežič et al. 2021
4. Zamarkova - Senekovič: Ciglar 2013
5. Močna: Tica 2013
6. Malečnik: Kramberger 2021
7. OC Maribor: Ravnik and Tica 2019
8. Ilovica: Lazar 2006
9. Dragomelj: Turk et al. 2022
10. Podgorica: Vojaković and Novšak 2022
11. Pržanj: Pavlovič 2023
12. Kamna Gorica: Svetličič et al. 2024
13. Cikava: Tica and Sagadin 2024
14. Podsmreka: Murgelj 2013
15. Mrzlo Polje and Ivančna Gorica: Svoljšak 2008
16. Sela: Horvat 2007
17. Podgrič: Plestenjak 2011
18. Dolenji Podboršt: Masaryk 2013
19. Dolenje Karteljevo: Bavec 2011
20. Dolenje Kronovo: Murko and Ciglar 2012
21. Bela Cerkev: Udovč 2022
22. Zemono 1: unpublished, see Bratina 2003
23. Zemono 2: unpublished, see Kavur and Petru 2003
24. Križišče: Novšak et al. 2019

and to the exhibition catalogue (Prešeren 2003) and video (IPCHS 2003) about the Slovenian motorways project.

Acknowledgements

I would like to thank Dr Bojan Djurić (University of Ljubljana), Dr. Dimitrij Mlekuž Vrhovnik (University of Ljubljana, and Institute for the Protection of Cultural Heritage of Slovenia), and Dr Tomaž Verbič (Research Centre of the Slovenian Academy of Sciences and Arts, Arhej d.o.o., and sole proprietor) for providing the various data needed for this study. Also, many thanks to Dr Dimitrj Mlekuž Vrhovnik for his PhD supervision.

In the Republic of Slovenia, as in most European countries, the protection of archaeological remains as cultural heritage is legally and procedurally included in state and municipal spatial planning, in accordance with the provisions of the European Convention for the Protection of the Archaeological Heritage (revised), adopted by the Council of Europe in 1992. In the procedures for the preparation of spatial planning documents for major interventions, the Institute for the Protection of Cultural Heritage of Slovenia is asked to prepare an expert assesment about the possible impact on the undiscovered archaeological heritage. The appropriateness of the methodology used for the detection of undiscovered archaeological sites is crucial for saving the archaeological heritage that would otherwise be destroyed by uncontrolled spatial interventions.

Research conducted by the author of the data paper, detailed in the accompanying article "Surveying along the slopes: evaluating the impact of geomorphic processes on the site discovery effectiveness", has highlighted shortcomings in the existing methodology for discovering archaeological sites on certain types of slopes. Archaeological fieldwork in the form of surface surveys have proven to be appropriate only in areas with stable topography, particularly on summits and upper parts of slope shoulders. On the lower parts of slope shoulders, footslopes and toeslopes, which are subject to erosive and dispositional topographic processes, the surface survey method is less suitable, as the author demonstrates by comparing data from surface surveys and excavations at 24 case study sites.

The database created by the author for research purposes has a high potential for reuse. In particular, the slope classification data files could be used in combination with the field survey and excavation data, for example, to analyse the distribution of archaeological remains from individual time periods at the sites and thus observe the dynamics of changes in the site-catchment topography. This could form the basis for the creation of models of past field use activities (e.g. Dotterweich 2008). However, as the author himself correctly pointed out, the greatest potential for data reuse lies in the area of cultural heritage resource management. The author's findings and the database could be used to improve the existing methodology for assessing impacts on archaeological heritage in spatial planning processes.