Aerial photo-based analysis of the hydromorphological changes of a mountain river over the last six decades: The Czarny Dunajec, Polish Carpathians.

摘要: Abstract Changes in hydromorphological conditions the mountainous Czarny Dunajec River over last six decades were investigated through analysis of archival aerial photos and contemporary orthophotos. The images from 7 dates between 1954 2009 used to evaluate changes selected parameters reaches delimited along river course. As a result channelization works in-stream gravel mining, most analysed course experienced dramatic alterations active zone: change multi-thread single-thread channel, narrowing associated with reduced occurrence or elimination channel bars islands, transformation gravelly bed bedrock–alluvial bedrock bed, stabilization banks engineering structures, disruption longitudinal continuity by transverse hydraulic structures. These largely habitat heterogeneity disrupted limited three-dimensional connectivity ecosystem. However, reach that had generally avoided these human pressures, such negative did not occur number low-flow channels proportion islands zone increased during study period. In all reaches, positive occurred riparian floodplain areas: wooded forest cover area decades. degradation was reflected significant impoverishment fish benthic invertebrate communities as well ground beetles inhabiting low benches. confirmed usefulness reconstructing temporal hydromorphology. features can be evaluated this approach is smaller than field-based assessments rivers but larger studies based on historical maps paleohydrological analysis.