Geographic Information Systems (GIS) as a tool for interpretation of neotectonics in the Podhale area, Poland

Abstract

A combination of approaches to the study of neotectonics is discussed. As an example, an analysis is presented for part of the Podhale region, where changes in the hydrogeological regime were observed. Comments are made on the manifestation of geological processes and principles in investigations of neotectonics, due to the results of precise digital terrain modelling (DTM) and geodetic surveys. The results obtained lead the authors to the conclusion that a reliable study on the geological activity of an area evaluated from considerations of river-channel morphology requires attention to changes in spatial development as a factor controlling the intensity of the hydrological regime. In such cases, a database of complex geodata information is required. A geodetic approach is presented, based on GNSS observations that become a new standard in geomorphologic studies. The results of GNSS observations provide quantitative estimates of displacements in the study area and allow assessment of their kinematics.The Liesek1 and Nowy Targ GNSS stations reveal a significant variation in the annual rate of uplift changing from 0.8 to 0.2 mm/yr, respectively. The difference in displacement azimuths (30° at Liesek1 and 300° in Nowy Targ) indicates rotation of the Podhale area. The GNSS-derived dissimilar displacement vectors imply the impact of neotectonic movements on the channel geometry of the Czarny Dunajec River. However, according to the analysis presented, this geometry is strongly influenced by land use and climate, resulting in the incision of river channels in Quaternary sediments. The annual rate of channel indentation reached a mean value of 1.4 cm, and a maximum value 5.5 cm during the studied period from 1965 to 1975. This outcome corresponds to a cumulative effect of neotectonic uplift combined with the results of human activity and climatic changes. Consequently, our study shows that a particular attention must be exercised in drawing conclusions on neotectonic displacements based solely on geomorphological observations.