11-06, 16:35– (Australia/Hobart), Main Auditorium
Regional geological mapping of the Kiunga 1: 250 000 map sheet was mostly done in the office with the use of remote sensing data and QGIS.
Geological mapping on a regional scale is undertaken very efficiently with the use of open-source software’s like QGIS and free GIS data like radar, DEM, and sentinel as seen from many examples around the world. The Geological Survey of PNG undertook 1:250 000 mapping of the south-west Fly Platform region of PNG not mapped since pre-independence. Due to the vast swampy wetlands, weather, climate, heavy rainfall, inaccessibility, and the shear size of the area, physical data collection by traversing and walking is very challenging. Geological interpretation of different rock types, and the contacts of different rock types, landforms, and structural faults was done wholly through the use of remote sensing data and the use of open-source software QGIS. Free radar, sentinel and DEM provided by USGS and European Space Agency were manipulated in QGIS and ArcMap to interpret landforms, rocks, and structures. Particularly band processing was done in QGIS, where swampy wetlands were better defined. Radar images provided clues of landforms characteristic of different rock types and hillshade and relief raster data processed from DEM were useful in interpreting geological structures. This concluded regional trends and structural relationships. The outcome was a pre-field geological map, from this target areas were generated to confirm interpretations made. Field mapping was helicopter-supported. While on the ground, QField, an open-source mobile software was trialed to collect data. Due to time constrains and helicopter waiting time, QField was not effectively used for data capture on the ground, however, its use was appreciated in helicopter aerial survey. Vector files of the pre-field geological map were placed in a geopackage file and viewed in real-time with moving locations seen in the air. This added confidence to interpretations made in the pre-field map and in addition, aerial mapping was done in real-time of features observed.
