Stream Water Temperature Modeling For An Alpine Catchment

Stream water temperature is an important key factor for water quality of rivers. Different approaches for stream temperature modeling have been developed over the past few decades and can basically be grouped into heat balance and stochastic models. Energy balance based stream temperature modeling depends on several types of heat fluxes and numerous approaches yet have tried to simplify this approach while scoping with accurate results. On the other hand strong correlation between air and stream water temperature has been reported since focus was put on stream temperature research. Therefore simple and reliable modeling approaches have been developed and verified for lowland streams. The objective of this work is to make use of an already developed spatially explicit hydrological response model in order to accurately simulate stream temperature for an alpine catchment based on estimated heat fluxes and thus further be able to providing information about water temperature at the sub-catchment scale. On the other hand the versatility of the existing stochastic modeling approaches is assessed with respect to the alpine area. The results reveal that (1) snow melt influences the energy balance approach significantly and thus makes parsimonious but accurate stream temperature modeling difficult and (2) regression approaches developed for lowland river systems are applicable to small alpine catchments.