Geodetic marks as material witnesses of geodetic networks development in Slovenia

Description:

The need to preserve property ownership rights, taxation and the military defence of the territory led to the realisation of the first systematic geodetic surveys of trigonometric networks of our land in the mid-18th century, forming the basis for coordinate systems, as well as topographic and land cadastral surveys. Different geodetic points are materialised by means of different types of geodetic marks (brick towers, pillars, smaller square-shaped blocks made from different natural stones or concrete, iron bolts etc.), which depend on the time and geodetic network in which they were installed.

The Faculty of Civil and Geodetic Engineering at the University of Ljubljana through its educational role and the Surveying and Mapping Administration of the Republic of Slovenia through regulation of practical procedures define the geodetic surveys in Slovenia. Additionally, the third pillar of geodetic survey knowledge exists, which has not yet been addressed properly. These are surveyors with many years of field experience who, as part of their practice, have developed procedures for how to perform individual surveys most optimally, depending on the local characteristics of the terrain they were dealing with (e.g., the influence of ground subsidence in areas of mining activity, the preservation ratio of different types survey marks, etc). Therefore, the main purpose of this project is to collect local surveying knowledge through scientific interviews that will be conducted with selected surveyors. In particular, we want to collect and professionally evaluate trough comparison with archive data local surveying practices dating back to the so-called classical surveying era. These are in danger of being completely forgotten, as classical surveying lost its importance with the official introduction of GNSS surveying in 2006 in Slovenia. Therefore, research interviews will be conducted mainly with retired surveyors, who still carried out field surveying before 2006. Only in this way we will be able to avoid the disappearance of knowledge related to past local surveying practices.

Additionally, these interviews will allow us to regionally assess the preservation rate of different types of geodetic marks being erected in different past systematic surveys carried out on our land over the last 200 years. This will allow the identification and evaluation of stories associated with individual geodetic marks. We will look at both geodetic as well as local stories, where the geodetic mark is serving as an anchor for preserving the collective memory of past events that took place in the vicinity.

We will focus in particular on geodetic marks, which represent points of horizontal geodetic networks and land cadastral points on the boundaries of the cadastral municipalities. As some geodetic marks erected as part of the first geodetic surveys served at the same time as land cadastral points as well as trigonometric network points. The boundaries of the cadastral municipalities, however, are based on even older boundaries of land estates. Therefore, they are occasionally marked by more than 200 years old geodetic marks.

With the help of the knowledge gathered on the characteristics of past surveys and the individual stories related to geodetic marks, we will also carry out an extensive campaign to promote geodetic marks among the general public. Due to poor awareness on the importance of geodetic marks among the general public, this often leads to the destruction of new as well as old geodetic marks that once already represented an important cultural heritage.

Key objectives:

The main goal of the project is to build a treasure trove of geodetic survey knowledge describing the characteristics of various local geodetic surveys being conducted before 2006, to prevent them to disappear in oblivion, as well as to establish safeguard of where and how classical surveying can be re-introduced, if GNSS satellite systems are severally hindered due to future unreliable geopolitical events.

Work packages:

Work Package 1 (WP1): Project management

Work Package 2 (WP): Comparative analysis of the past systematic geodetic network surveys

Work Package 3 (WP3): Retrieving and studying the geodetic oral testimonies

Work Package 4 (WP4): Retrieving and studying the local public oral testimonies

Work Package 5 (WP5): Analysing the preservation rate of different types of geodetic marks

Work Package 6 (WP6): Dissemination