Historical flood reconstruction in a torrential alpine catchment and its implication for flood hazard assessments

作者：Yihua Zhong, Juan Antonio Ballesteros‐Cánovas, Adrien Favillier, Christophe Corona, Gregor Zenhäusern, Alberto Muñoz-Torrero Manchado, Sébastien Guillet, Florie Giacona, Nicolas Eckert, Jiazhi Qie, Georges Tscherrig, Markus Stoffel · 发表于：Journal of Hydrology · 年份：2023 · DOI：10.1016/j.jhydrol.2023.130547 · 被引用次数：10 · 研究领域：Flood Risk Assessment and Management、Hydrology and Watershed Management Studies、Hydrology and Sediment Transport Processes

Flood marks and descriptions of past floods in archival records are valuable sources of information to complement the often short – and sometimes lacunary – systematic records provided by gauge stations, especially in mountain and smaller catchments for which the network of recording stations is still fragmentary. Yet, historical accounts of floods are only rarely used to calculate discharge during past floods and to complement estimates of flood frequency and magnitude. This is because the definition of flood types and the reconstruction of past topography of the now urbanized riverscapes is often challenging. Here, we employ an approach by which we combine (i) archival (1331–1965) and continuous gauge (1966–2020) records of past floods, (ii) information on past topography and mitigation measures found on topographic maps and contemporary documents specifying the dimensions of contemporary engineering plans and (iii) a hydraulic model to derive a c. 700-year history of flood activity and related discharges for the Saltina River, Brig-Glis (Valais, Swiss Alps). Periods of increased flood activity match with flood-rich episodes in the Rhone River and high lake levels at Lago Maggiore (Ticino), and the time series passes stationarity tests since at least 1828 CE. For a total of 32 floods occurring prior to the installation of the gauge station in 1966, we provide discharges following a descriptive classification, and demonstrate that major floods occurred in 1755 (∼140 m3s−1), ...