(BEING CONTINUED FROM 9/02/2018)
An image-based digital retrospection of a demolished village Breginj and its landscape change analysis
The mountain village of Breginj was for centuries the centre of a self-sufficient and highly organized local community. Its extraordinary folk architecture was protected as a first category cultural monument. This lively area bordering Italy was subject to politically driven decisions after it was severely struck by two successive earthquakes. The way of life has changed and the situation has left striking evidence in the landscape evolution of the past decades.
With this contribution we aim to raise awareness and show the potential of historical photography and a digital image-based retrospection of places that may no longer exist, but have left important traces in human and landscape history. Having in mind the retrospection of a lost village and its relevance through time we used historic aerial photographs and two different approaches to obtain: • a detailed 3D village reconstruction (with SfM modelling) and • a landscape change study (with object-based image analysis).
Breginj and image-based digital retrospection
Cultural heritage is frequently photographed. It may be destroyed or altered, and photographs become the only evidence of its existence and modification. In the case of Breginj, the village completely changed its location and structure. This, together with the general depopulation of rural areas, gradually resulted in a change in the way of life and the use of the surrounding land. Our question was how, where, and to what extent can the landscape change in a few decades? Modern image processing techniques support the production of a variety of digital approximations of historical objects. Digital reconstruction of demolished Breginj is important because it: • enables a spatial and temporal retrospection of the historic processes, and the preservation and dissemination of the memory of this once remarkable village, and • gives measurable evidence of the effects of post-earthquake reconstruction and political decisions on the structure and function of the landscape and people.
Structure-from-Motion derived digital model A series of six vertical aerial photographs was taken after the first earthquake in May 1976 to observe the destruction. We used these images to create a digital reconstruction of the demolished village using the Structure-from-Motion technique. The photographs were taken in a single flight line and every point on the ground can only be seen on a maximum of three images, which is not the best arrangement for this type of reconstruction. Despite this two detailed elevation models were produced: the first from full resolution images and the second from reduced resolution images (by 55%). The latter model better defines the buildings despite the same processing settings. Because the reconstruction is only based on aerial photographs so far, the computed model is not of the best quality, but it still provides a good basis for a retrospection of the settlement.
OBIA land cover change
Object-based image analysis (OBIA) is an approach to semantically analyse imagery that was developed for the classification of very high resolution imagery. Image-objects represent ‘meaningful’ entities or scene components that are distinguishable and form the geographical space evidenced in an image. OBIA consists of two distinct steps: segmentation (delineation of homogeneous zones) and classification (semantic grouping of segments). The result is a classified geographical space, according to its natural elements, land cover or land uses. OBIA of imagery from different periods enables quantitative and contextual tracing of changes in the landscape.
Photographs of the old village of Breginj can no longer be taken. But 3D reconstructions based on historic images might add to cultural resource management and services. A successful retrospection of landscape change and social processes demonstrates that aerial imagery can be a valuable resource for geographers, historians, and archaeologists.
Tatjana Veljanovski1 / Žiga Kokalj1,2
1. Research Centre of the Slovenian Academy of Sciences and Arts / 2. Centre of Excellence for Space Sciences and Technologies
Archaeological landscape in Romania: 10 years of surveys and documentation
It is now 10 years since the former Institute for Cultural Memory-CIMEC (www.cimec.ro), today part of the National Heritage Institute (patrimoniu.gov.ro), started aerial and cartographical surveys in order to improve the National Archaeological Record (ran.cimec.ro), mainly in Southern Romania along the Lower Danube Plain, Central Dobrudja, and up to Sub-Carpathian Hills but also in Northern Romania, Botoșani County. We have established the geographical location and context for known archaeological sites, identified unknown features and recorded changes in the landscape, combining aerial surveys with the study of historical maps and GIS techniques. The main activities were: aerial photo investigation (25 flights & 7500 images), image interpretation and digital archive creation, using aerial imagery to map 3000 archaeological sites, updating the spatial distribution of settlements in Romania (13,756 places) and creating a cooperation network through the project “Archaeological landscapes. Outlook, history and evolution”, developed between May and October 2014, in partnership with other Romanian public cultural institutions.
Compile an aerial photo archive
After implementing the pilot project Mostiștea Valley (2005- 2007) under the auspices of the “European Landscapes-Past, Present and Future” European project, we continued the aerial investigation of the Southern Romanian Plain (Neajlov, Argeș, Teleorman, Ialomița and Olt rivers), in Ilfov and Prahova Counties, along the motorways in construction (A2 BucharestMedgidia-Constanta, A3 București-Ploiești and Sibiu-OrăștieDeva) and between the Danube and Black Sea in Central Dobrudja, in order to enrich the National Archaeological Map of Romania (map.cimec.ro). The main outcome is a database that contains almost 4000 processed photos from around 7500 photos taken from air. We assigned precise geographical coordinates and metadata such as: the nearest settlement, date of flight, county, mark type, general observation and landscape changes.
The operation will continue until the entire collection is completed. The photo archive is accessible on-line through a web site and a dedicated web GIS application entitled “Landscapes” (www.peisaje-arheologice.ro).
Using aerial orthophotoplans for sites inventory: The archaeological repertoire of Botoșani County
We contributed to the county sites inventory. Our main activity was to map archaeological sites using both topographical maps and orthophotoplans produced by the Topographic Military Directorate. All the 1809 sites were vectorised in a GIS project (using polygons as geometry) and were recorded in the National Archaeological Record. Additional resources and techniques were used: satellite imagery and field surveys. Information was provided about administrative location, state of conservation, levels of natural or human risks, type of inhabitation, time span and bibliography
The project was carried out in partnership with Ph.D. Octavian Liviu Șovan from Botoșani County Culture Directorate. The outcome was a volume accompanied by a DVD with topographic maps of each administrative entity, scale between 1:20,000 and 1:25,000, obtained both by vectorising settlements, roads, contour lines, rivers and lakes from orthophotoplans, and using different DEMs (www.cimec.ro/arheologie/repertoriulbotosani/index.html). Copies of the volume were sent to local authorities and schools to be used in heritage conservation and education programs. A successful project: Archaeological landscapes. Outlook, history and evolution (2014) The project was developed by the National Heritage Institute (CIMEC Department) in partnership with the National History Museum of Romania, University of Bucharest (Geography Department), the Topography Military Directorate and UMR 7041 ArScAn-Équipe Archéologies Environementales (France). The project, funded by the Romanian Ministry of Culture, was placed under the auspices of ArcLand and supported its goals and activities by promoting the concept of archaeological landscape and its research methods within the Romanian scientific field, and by raising awareness of the intrinsic value of heritage among specialists (archaeologists, historians, cultural operators, students) and the wider public. The final event was an international conference entitled “Approaches to Archaeological Landscapes. Tools, Methodology and Case Studies (22nd-23rd October 2014, Bucharest). The event brought together 30 specialists, foreigners and Romanians, among them also ArcLand members, who tackled the topic of the archaeological landscape concept, displayed different methodologies and shared their experience in the field of landscape studies. An aerial photos exhibition hosted at the National History Museum of Romania accompanied the event.
Irina Oberländer-Târnoveanu1 / Bogdan Șandric1 / Iuliana Damian1 / Oana Borlean1 / Adriana Vîlcu1
1. National Heritage Institute
(TO BE CONTINUED)