
I never thought I will ever cross-post news from the yellow press leaders of BILD. Well, never say never, here it is (even covering a hydrological issue!): Trocknet die Elbe aus? (will River Elbe run dry?)
Despite BILD claims that the situation is ‘historic’, water levels and – what is hydrologically more meaningful – discharges have been lower/worse regarding historic time scales (e.g., in summer/fall 1904, summer 1911, winter 1954 or summer/fall 2003).
Here is a brief comparison of some low flows (not a complete list of extreme values!) for the Elbe gauge at Dresden (mean annual low flow is 111 m³/s):
1904 ~60 m³/s
1911 ~55 m³/s
1954 ~25 m³/s
2003 ~100 m³/s*
2015 ~70 90 m³/s**
*The 2002 flood quite well filled the reservoirs in the upper Elbe catchment so that there was enough water for low flow mititgation by controlled release in the very dry summer of 2003.
**On July 16.
However, it is quite likely that water availability and therefore river flow will futher decrease during summer and the first decades of fall. Thus, there is a (yet not exactly specifiable) probability of a worsening low-flow situation on the mid and long run.
Edit (as per 12 August 2015) – keeping track of the further devlopment of the current low flow period:
16 Jul. 2015 ~70 90 m³/s
25 Jul. 2015 ~65 85 m³/s
07 Aug. 2015 ~65 85 m³/s
10 Aug. 2015 ~60 80 m³/s
12 Aug. 2015 ~78 m³/s
N.B.: Intitially given figures for low flow discharges had to be altered in the meantime due to operational flow measurements carried out by WSV required an adaption of the gauge’s rating curve.
For the month of August, but for the discharge at Neu Darchau (Hamburg), there is a forecast of 94 m*3/s issued. And for this station this value is the lowest one in the last 150 years or so.
Hi Monica,
Thanks for your post and the additional information. I am, and I was, specifically referring to the upper Elbe River (which is more or less the river course down to the city of Riesa, Saxony). Additionally you have to keep in mind that the Vltava River, which contributes more water than the Elbe, and other Elbe tributaries, are regulated by dams and therefore, the low flow situation can be at least slightly improved (by ca. 20 to 25 ³/s) up to now in the upper Elbe (emphasis on “up to now”).
Furthermore, I was not taking into account any forecast scenarios. However, if the situation will not substantially improve (and in fact, this is what it looks like), such ‘historic’ discharges seem possible, not to say likely, also for the upper Elbe.
Best,
Andy
Hi Andy,
It was really nice to find your blog. I’m working in more or less the same direction.
It would be nice to see the forecast for the month of August for Dresden. Unfortunately I do not have access to the data from Dresden and I have no idea what is going to happen. I’m doing the forecast for Elbe, but for Neu Darchau at monthly and seasonal time scale. I just issued the forecast today for the month of August and it looks pretty bad. I’m aware that the situation is a little bit different for Saxony, but it’s still unbelievable the current situation. And it seems that Elbe is not the only river affected. I just hope that my forecast will be wrong this time and that the things will improve.
All the best,
Monica
Hi Monica,
are you aware that the Elbe is a federal waterway and therefore the Federal Institute of Hydrology (http://www.bafg.de/DE/Home/homepage_node.html) and the Waterways Administration (http://www.wsv.de/) are responsible for issuing and disseminating low flow forecasts?
Here you can find the current short-term forecast for Dresden: https://www.elwis.de/gewaesserkunde/Wasserstaende/wasserstaendeUebersichtGrafik.html.php?pegelId=70272185-b2b3-4178-96b8-43bea330dcae
For further reading, I can recommend the WMO/IHP Handbook on Low Flow Estimation: http://www.wmo.int/pages/prog/hwrp/publications/low-flow_estimation_prediction/WMO%201029%20en.pdf
BTW: Are you working for a NGO?
Best,
Andy
Hi Andy,
I’m actually working together with Bafg. We have a common project for the next 6 months to test my forecast scheme for the monthly and seasonal outlook. For my PhD thesis I’ve developed together with a colleague a forecast scheme for the seasonal streamflow. I’m mostly interested in floods, but Bafg needs more parameters so I’m testing my model for what they need. And I’m very well acquainted with the low flow manual. I’m working at Alfred Wegener Institute for Polar and Marine Research (you can have a look here http://www.awi.de/ueber-uns/organisation/mitarbeiter/monica-ionita.html ), but one third of my working time I’m doing this forecasting stuff, because it’s the thing that I like the most.
All the best,
Monica
Hi Monica,
maybe my answer was sort of clumsy, but it was a bit hard to conclude your background from your statements. For the upper Elbe, at the moment, approx. 20 to 25 cms are supplied by controlled release from the Czech side. Therefore, including operational dam release rules (Czech Dam Authority Povodi) should essentially be considered for a mid-term forecast. If you are interested, we could switch this thread to an email or phone conversation?
Best,
Andy
Hi Andy,
I didn’t want to impose. My email is
left_blank_to_avoid_spam.At the moment I’m on vacation, but I will be back at my office next week.
I’m doing the forecast mostly from a climatological point of view. But as you said, it’s better to communicate on email or phone.
Just send me an email with you email address and I can give you more details about what I’m actually doing 😀
All the best,
Monica