'May God bridge river Tywi!' Integrating medieval and contemporary representations of flooding and fluvial geomorphology

Public perceptions of climate change impacts and mitigation strategies can be influenced by societal, cultural and historical factors. This can present significant challenges to policy makers and regulatory agencies who try to communicate environmental management practices based on scientific data. Data from historical cultural sources which may be more accessible to the non-specialist audience are rarely presented in this context, if at all. This paper analyses a praise poem by Welsh medieval poet Lewys Glyn Cothi (c. 1420 – 1490) to two of his patrons, Llywelyn ap Gwilym and Henri ap Gwilym, noblemen of the Tywi valley, south-west Wales. This poem is particularly significant as it imaginatively describes a flood on the river which obstructed Lewys from travelling from one patron’s house to the other. A common topos in Welsh Medieval poetry is used as Lewys compares the flood to Biblical flood of Noah, but also to large rivers and watercourses in Wales and abroad. Tantalising information is provided on the nature of floodplain geomorphology, the extent of the flood, as well as its impact on riparian vegetation and agricultural crops. Alongside this powerful poetic imagery we present scientific data (time-series of river discharge, geormophological maps and LiDAR) that provide alternative, yet equally creative, representations of the contemporary and historical hydrology and geomorphology of the area. We argue that presenting imagery from cultural, artistic and scientific sources in combination can potentially offer a valuable new perspective on historical flooding. In particular, greater public visibility and awareness of cultural sources such as medieval poetry can provide a human voice to scientific data and may increase public understanding of the long-term nature context of climate change and human-environment interactions.