Periodically changing currents regimes

Fig. 5 The current River Rhone temperature regime (grey, black) as a result of damming (and partly climate change) compared with daily data (red, blue) from one century ago (1886 and 1904/5). The data has been collected at Porte du Scex by [19], by [18] and by [16] for 1886 (blue), 1904/5 (red), and in the last decades (grey, black), respectively. The red dots are daily values (afternoon). The black bars represent minima and maxima for the period 1982-2002. The hydropower operation has a smoothing effect on the temperature below the outlets in the River Rhone In winter, the current temperature is about 2°C above natural (warming from prewarmed reservoirs) and in summer about 1 °C cooler (less riverbed friction electricity production). The annual average remains almost constant. Details in [10]...

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