Remote sensing and GIS techniques to monitor morphological changes along the middle-lower Vistula river, Poland
Nowadays, the combined use of Remote Sensing data and Geography Information System (GIS) tools is becoming mainstream in evaluating the river channel evolution at many spatiotemporal scales, thanks to the low costs of such techniques and the increased availability of high-resolute satellite images. These methods can be applied to investigate large ungauged basins and accounting for relatively long periods, becoming a precious support tool for water management strategies at the reach scale. The medium-term planform changes of an 80-km reach of the Vistula River downstream of Warsaw, Poland, were evaluated considering the Modified Normalized Difference Water Index (MNDWI) of four Landsat images acquired in 1985, 1994, 2004 and 2017, which referred to similar hydrological conditions. The study highlighted that, by combining satellite information with semi-automatic digital processing procedures developed in GIS, it is possible to see that the reach resulted quite stable in the whole period under a morphological point of view, even if a reduced depositional trend along the banks is visible, especially in the last decade, probably because of a slight increment in the frequency of high water events. The results of this research can be helpful in better designing the future management strategies of this middle-lower reach, also in the light of the inland navigation projects started among Europe and affecting the Vistula River.