Material resources demand and flows of hydraulic structures to prevent societal impact of extreme events (Topic 2)

Extreme events (floods, low flow) induce societal mitigation and prevention measures. In the 19th century, technical interventions became the standard. Such structures require huge amounts of material resources, particularly minerals, metals and synthetic materials. Societal developments such as intensifying use of floodplains or new requirements of shipping for low-flow channelization challenged existing constructions calling not only for maintenance but also for improvement and adaptation (heightening of dikes, deepening of low flow channels, etc.). Up to now, resources demand and material flows for hydraulic structures to mitigate and prevent the adverse effects of extreme events on societies have been rarely studied, neither for the present nor for the development in the last 200 years. Further, links between the implementation of hydraulic structures, occurrence of extreme events and societal factors (e.g. floodplain use, shipping) are still poorly understood. Main objective/research question/hypothesis This PhD-thesis will investigate (1) the resources demand of hydraulic structures to prevent societal impact of extreme events on the Austrian Danube since the 1830s and (2) the interactions between hydrology, technology and society. Main research questions and hypothesis are: • What material resources have been used for the construction of hydraulic structures on the Austrian Danube since the 1830s? How and when did demand increase? We assume that demand has increased at certain times in connection with actual events (flood damage, new shipping requirements, etc.). • How are extreme events, construction of hydraulic structures, and social processes or technological developments (increase of built-up land in floodplains, larger ships) connected, and how has policy influenced this? We hypothesize that this relationship is more complex than often claimed as shown by a case study on the River Traisen. The PhD links approaches and methods from environmental history, hydraulic engineering, water management and spatial planning. It is based on a literature review, screening and pre-processing of historical sources (reports on water engineering measures, historical maps, relevant laws, directives, spatial plans, ; processing of data in a geodatabase; data analysis (esp. material flow accounting4) and conceptualization. The PhD combines a large spatial scale study (whole Austrian Danube) with case studies focusing on the development of built up land in flood plains and policies to regulate this increase.