Akademik Veri Yönetim Sistemi
76th Geological Congress of Türkiye with International Participation - 2024, Ankara, Türkiye, 15 - 19 Nisan 2024, ss.554
Maps are the fundamental outputs used during the spatial analysis and interpretation of geological field studies based on spatial data. Map elements acquired by geodetic observation from space or by terrestrial techniques are connected to national or international reference systems. Geological engineers generally evaluate their data in Google Earth or commercial software. The main purpose of this study is to introduce the fundamental (horizontal and vertical) reference systems and to enable them to effectively use geological data in the GNU environment. The study consists of three main parts. 1) Coordinate systems, 2) GNU (GNU's not Unix) environment, 3) text formats and geological mapping.
1) Geodetic reference systems are divided into two: vertical (Geoid) and horizontal (ITRF, UTM, etc.). While the heights of maps are measured from Geoid, the horizontal observations and calculations are made according to reference ellipsoids (GRS80, WGS84, etc.). The physical three-dimensional of a point depends on knowing its positions in both reference systems. In this study, the importance of the reference systems, and the map griddings that enable the connection of geological data to reference systems will be emphasized.
2) Nowadays, GNU-OSs (Linux) are used extensively in almost every field (computers, mobile phones, vehicles, etc.). The main reason for this is that no OS license fee is paid. There are many Linux-based systems developed by different groups. The most widely preferred Linux versions on which countless applications have been developed are Debian-based (Debian, Mint, Ubuntu, Kali-Linux, Pardus, etc.). The fastest updated Linux versions of most programming languages, GIS, (Geographical Information System) and CAD (Computer-Aided Design) software developed for engineering purposes are also Debian-based. In this study, QGIS (Quantum GIS) software for geological mapping was used on Linux-Mint, and auxiliary software was developed in C\C++ environments.
3) Three basic topological features are used to establish a spatial relationship between GIS and geological data. These are points, lines, and areas. Numerical geological data providing these topological features can be easily transferred to QGIS as CSV (Comma Separated Values) text files and semantic information using WKT (Well-Known Text) formats. These CSV files can also be easily created with any GNU spreadsheet program.
The concepts and processes required for geological mapping in the GNU environment are briefly summarized under the three main parts given above. In addition to introducing the general features of the GNU software that will be used for the parts described above, a QGIS output containing national and international map gridding along with a geological map example will be shared with the readers as the final product of the study.