Különböző felbontású domborzatmodellek befolyása vulkáni salakkúpok morfometriai paramétereire – összehasonlító tanulmány

Abstract

Since the early 2000s, rapidly improving resolution digital terrain models (DTMs) have been used increasingly as input data in various geomorphometric studies. They are excellent for studying large areas, clusters, and geomorphological forms, and with their help, it is not difficult to analyse hundreds of forms. A common problem in the statistical evaluation of DTMs is that the results may depend on the resolution of the input data. My aim in this study was to examine one of the simplest volcanic forms, the cinder cones, from a geomorphometric point of view and to show the extent to which the result was affected by the different resolutions of the DTMs. The study areas were the San Francisco Volcanic Field (SRTM DTM resolutions 30 and 10 m) in Arizona (USA) and ChaĒne des Puys (LiDAR DTM resolutions 90 and 0.5 m) in Auvergne (France). Polar coordinate transformation (PCT) was used, descriptive parameters (cone height and average slope) were calculated, and a comparison was carried out (with the help of the Mann-Whitney test) to show statistically significant differences for age groups and values derived from different resolutions. The slope values are the most sensitive to the resolution of the input data: comparing the age groups with themselves, but with values calculated from DTM with different resolutions, the slope shows a statistically significant difference in almost all cases. Based on the tests, an ideal resolution for scoria cone morphometric examination should be at least 10 meters, but if it is an area that contains older, smaller cones, a better resolution is a better choice. On the other hand, the 0.5 meters seems unnecessary for symmetry/parameter tests.