Time series database and QGIS-based management of national leveling data

Abstract

Republic of Korea's national leveling infrastructure has been developed for decades; however, its management faces challenges in inefficient manual processes for maintaining summarized calculation sheets (SCSs), loop-misclosure check and calculation sheets (LCCSs), and leveling network diagrams, which are traditionally stored in Microsoft Excel and computer-aided design formats. This study addresses these issues by designing and implementing a time series database that replaces the existing SCSs and LCCSs and a QGIS-based network diagram that is automatically generated via pyQGIS code. The new database links benchmarks, routes, and loops in a relational structure. At the same time, a QGIS project is manipulated from the database, allowing seamless data visualization and analysis. The national leveling data, updated until January 2023, were migrated into the database, and errors were detected and revised during the migration. The analysis identified discrepancies in duplicate benchmarks within LCCSs, with 19.5 % having inconsistent status values and 66.5 % showing height discrepancies, though their impact on network adjustment was negligible. Latitude (2.6 %) and gravity (1.1 %) inconsistencies may have influenced height correction but are expected to be resolved with NGII's finalized benchmark database. Additionally, 94.1 % of leveling benchmarks were successfully updated to unified benchmarks, and analysis of 2023 survey data revealed that 85.1 % of routes were remeasured, while 11.6 % were newly established and measured. The key advantages of the introduced method include error detection and correction of existing leveling data and time series management to track changes in the leveling data over time. The elements can now be visually inspected and revised with improved efficiency, and new loops and routes can be managed more efficiently via a visual interface. This solution significantly enhances both the integrity and reliability of the national leveling infrastructure.