Publication

Improving stream flow discharge modelling during snow melt

Abstract

The importance of the snow cover for the hydrological cycle is well known but the understanding is still limited. For example, the effect of rain-on-snow on melt water runoff and the coupling between spring snow melt and stream flow discharge are difficult to describe quantitatively due to the complex nature of natural snow covers. Snow height can very over short distances and processes influencing the snow cover development, such as solar radiation and wind, are spatially highly variable in complex alpine terrain. These effects influence the layering of the snow cover and because layers with different snow properties also have different hydraulic properties, the relation between snow melt and snow cover runoff gets rather complex. However, it has already been shown that describing melt water flow through a snow cover using Richards equation, that takes into account the snow stratigraphy, is improving snow cover runoff estimations locally. In this study, an advanced physical based snow cover model that solves Richards equation (SNOWPACK) is used in a distributed way in a spatially explicit model for alpine terrain (Alpine3D). The model setup simulates the snow cover development and stream discharge over a snow season for the Dischma catchment in Switzerland. A comparison between modelled and observed discharge of the catchment outlet shows that solving Richards equation for snow yields better agreement than simpler (bucket) methods for liquid water flow in snow. The simulations also show a strong variation in contribution of snow cover runoff between areas, depending on slope exposition. This can be associated with different shortwave radiation input for snow melt. The results show that important improvements in estimating the contribution of snow cover runoff to the hydrological cycle can be achieved by solving Richards equation for snow. However, future research should also focus on a better estimation of hydraulic properties for a wider range of snow types and the understanding of lateral and preferential flow in snow.

About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Related concepts (33)
Snow
Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout its life cycle, starting when, under suitable conditions, the ice crystals form in the atmosphere, increase to millimeter size, precipitate and accumulate on surfaces, then metamorphose in place, and ultimately melt, slide or sublimate away.
Snowmelt
In hydrology, snowmelt is surface runoff produced from melting snow. It can also be used to describe the period or season during which such runoff is produced. Water produced by snowmelt is an important part of the annual water cycle in many parts of the world, in some cases contributing high fractions of the annual runoff in a watershed. Predicting snowmelt runoff from a drainage basin may be a part of designing water control projects. Rapid snowmelt can cause flooding.
Meltwater
Meltwater (or melt water) is water released by the melting of snow or ice, including glacial ice, tabular icebergs and ice shelves over oceans. Meltwater is often found during early spring when snow packs and frozen rivers melt with rising temperatures, and in the ablation zone of glaciers where the rate of snow cover is reducing. Meltwater can be produced during volcanic eruptions, in a similar way in which the more dangerous lahars form. When meltwater pools on the surface rather than flowing, it forms melt ponds.
Show more

Graph Chatbot

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.