Geomorphic Changes of the Scott River Alluvial Fan in Relation to a Four-Day Flood Event

A four-day glacier-melt flood (13–16 August 2013) caused abrupt geomorphic changes in the proglacial gravel-bed Scott River, which drains small (10 km2) Glacier catchment (SW Svalbard). This type of occurs on Svalbard increasingly during periods abnormally warm or rainy weather summer early autumn, and probability occurrence grows direct proportion to increase temperature and/or precipitation intensity. In 2013, measurement season, highest daily (17 mm) occurred 13 August. During following four days, it constituted total 47 mm, i.e., 50% for period 2013. The largest 20 years was by high with a synchronous rise from about 1.0 8.6 °C. These values exceeded multi-year averages (32 mm 5.0 °C, respectively) at an average discharge 0.9 m3/s (melt season mean 1986–2011). conditions rapid response river dominant (90%) glacier-fed. 4.6 m3/s, initiated glacial flood, mobilized significant amounts sediment bed channel. Geomorphic within alluvial fan as area 58,940 m2, located mouth were detected multi-sites terrestrial laser scanning using Leica Scan Station C10 then estimated Change Detection (GCD) software. found involved 39% (23,231 m2). flood-induced lowering (erosion) covered 26% (6035 m2), resulting removal 1183 ± 121 m3 volume. final phase two times more (1919 344 m3) re-deposited surface, causing aggradation 74% its (17,196 resulted surface 0.2 m rising (deposition) 0.1 m.