Exploiting the Danube River: regulation in Bratislava depicted in historical works of art

Historical depictions of towns, castles or fortresses, along with additional research (archive-historical, archeological and architectonical) provide a picture of how former settlements were shaped, developing and modified. Some vedute of cities along large rivers capture early river engineering works. In this study, 19 portrayals of the Bratislava City (Slovakia) were analysed showing hydroengineering structures on the Danube River. Originality of the used approach is in comparing the old paintings (graphics, vedute) with cartographic sources that depict river regulation in detail which are little known to date. Recently, digitization of cultural heritage and its public access via internet online portals enable user-friendly analysis and comparison of a great number of graphic sources with contemporary reality. Danube at Bratislava was regulated in three phases, with the earliest works dating back to 1772 - 1780. The second stage occurred between 1832 and 1834, followed by a third phase of systematic river channelizing (1886 - 1896). During these modifications different engineering structures were constructed, including protective embankments and stone revetments to stabilise river banks and for river-flow contraction. Tips of important islands were stabilised and side channels were cut off (the side channel of Chorvatske rameno). Some structures were later destroyed by floods, some exist until present (Viedenska cesta highway). Engineering structures have affected both channel morphology and visual configuration of the waterfront. Detailed analysis of the studied work of arts confirmed that even painters of the Biedermeier period - despite their romanticising tendencies - mostly adhered to the realities of riverscape. The study demonstrates a new kind of data which can be potentially extracted from artworks. Comparing vedute with old maps is also useful for dating of some pictures, tracking their genesis or copying. Therefore, old paintings may bring new kind of information not only for geosciences, specifically for fluvial geomorphology, but also for the history of hydraulic engineering.