Original paper
Application of the model ‘Heat Source’ to assess the influence of meteorological components on stream temperature and simulation accuracy under heat wave conditions
Trimmel, Heidelinde; Gangneux, Clement; Kalny, Gerda; Weihs, Philipp
Meteorologische Zeitschrift Vol. 25 No. 4 (2016), p. 389 - 406
60 references
published: Sep 6, 2016
published online: Mar 10, 2016
manuscript accepted: Nov 20, 2015
final revised version received: Oct 27, 2015
manuscript revision requested: Sep 29, 2015
manuscript received: Apr 29, 2015
Open Access (paper may be downloaded free of charge)
Abstract
Stream temperature is one of the most important factors for aquatic organism, but also regulates drinking water quality, which are both threatened by temperature rises. Atmospheric heat fluxes are primary drivers of stream temperature changes, all of them dependent on the rivers' openness to sky.To be able to simulate stream temperature in rivers of complex terrain and shaded by riparian vegetation a deterministic model including all shading processes was used and validated for the application for Eastern Austrian lowland rivers during summer and the heat wave 2–8 August 2013. The global radiation was included as direct input, which lead to an improvement. It is shown, that both net short wave radiation and evaporation are the most influential components under heat wave conditions and that both are subject to the influence of shading by topography and vegetation. The forward propagation of measurement imprecisions of atmospheric input parameters on simulated water temperature was calculated. The total model imprecision caused by measurement errors of sky obstructing elements (+1.24/−1.40 °C) exceeds the error caused by measurement errors of meteorological input parameters (+0.66/−0.70 °C). The most important sky obstructing elements are vegetation height and vegetation density. A total model imprecision caused by measurement errors of meteorological and shading input parameters is calculated with +1.90/−2.10 °C. While the errors caused by meteorological input are expected much smaller under normal conditions, sky view reducing errors are realistic or even underestimated.
Keywords
stream temperature simulation • energy balance • sensitivity • shade • vegetation • heat wave