River floods in glacier-covered catchments of the High Arctic: Billefjorden-Wijdefjorden, Svalbard
River discharge from partly glacier-covered catchments is controlled by its storage on various time scales and its release from ice and snow during melt-out. These discharge processes depend on seasonal reactions to meteorological conditions, generating variable river discharge magnitudes, including floods. Four types of meteorologically driven floods in glacier-covered catchments were distinguished, depending on the seasonal variations in the dominant water supply source and the type of storage. These four types of floods were induced by: 1 - spring/summer snow-melt; 2 - mid-summer ice and snow-melt; 3 - rainfall events, and 4 - fohn phenomena. Additionally, sudden water drainage from ice-dammed lakes of various origins may generate amounts of discharge surpassing total annual discharge. Flooding events from the High Arctic glacier-covered catchments in the area between Billefjorden and Wijdefjorden, in the central part of Spitsbergen (Svalbard), were characterised. Floods occurred more than once per ten days during the ablation season. These floods are considered the main agents of proglacial relief remodelling, sediment transport and deposition.