Snow is an important component of the hydrological cycle. The seasonal storage of water in the snowpack may last over months, and its retarded release is a major factor of reliable water supply for ecosystems and human needs during dry periods. Rapid snow melt can however cause destruction through sudden floods, mostly in combination with rainfall. Thus, water demanding downstream regions, settlements and infrastructures are highly vulnerable with regard to the presence or absence of snow in the headwaters. Increasing air temperatures and changing precipitation patterns driven by climate change will modify snow conditions and thus lead to changing water supplies. Snow cover is also a critical factor in global and regional energy balances. The consequences of reduced snow duration and an increasing share of rainfall on precipitation will completely change the land-atmosphere interactions and thus lead to further modifications of the regional climatic conditions.
The spatial heterogeneity of snow accumulation and ablation in complex terrain is triggered by multiple causes, among which vegetation and topography play a major role. However, the reliable estimation of snowpack variability remains a challenge. Traditional methods, including new direct measurement techniques, provide accurate information about snow conditions at the point scale. But they lack high observation frequency and spatial coverage. Remote sensing techniques have been widely used for snow monitoring in recent years, and they are able to monitor the snowpack over large spatial domains. Yet, beside limited temporal resolution, remotely sensed data is often biased by snow misclassifications, and cloud cover frequently limits the availability of snow related information. Hydrological models which include snow dynamics require reliable input data, but these have limited availability especially in mountainous regions. The simulation of snowmelt frequently lacks sufficient spatial and temporal detail, so that forecasting of snowmelt runoff for operational purposes is still a challenging task.
The SnowHydro conference will address the range of topics with regard to snow and its significance for hydrology. It aims at bringing together experience from experimental research, hydrological modelling and remote sensing and it will facilitate joint research on snow science.