Snowll 1 . elt and slushflows : hydrological and hazard ill 1 . plications

In ma ny high-latitude areas, slushflows occ ur frequently during th e snowmelt period but inform ation on the initiat ion mechani sm is rare. Field observations and measurements of slush fl ows in northwestern Spitsbe rgen and in northern Sweden demonstrate the role of meltwater accumulation and the hydraulic pressure gradient in the rel ea se process. Snow metamorphism is revea led to be of minor importance in the observed events. The monitoring of water-pressure development in a saturated snow cO\·er demonstrates that preferred release areas are within low-grad ient \·alley sections, where meltwater inflow is higher than outflow. Slushflows consist of mudflow-like flowage of water-saturated snow along st ream courses. They represent transitional processes between flll\·ia l floods and avalanches. On the other hand, they possess unique characteristics concerning release and mo\·ement. The comparative e\"aluation of definition items for fluvi a l fl oods, slushflows and avalanches offers basic data suitabl e for a risk assessment.