Rofenache

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Rofenache
The Rofenache above Rofen

The Rofenache above Rofen

Data
Water code AT : 2-8-92
location Imst district , Ötztal Alps , Tyrol
River system Danube
Drain over Venter Ache  → Ötztaler Ache  → Inn  → Danube  → Black Sea
origin Glacier mouth at the Hintereisferner
46 ° 49 ′ 2 ″  N , 10 ° 47 ′ 48 ″  E
Source height approx.  2500  m above sea level A.
confluence at Vent with the Niedertalbach to the Venter Ache Coordinates: 46 ° 51 ′ 28.6 ″  N , 10 ° 54 ′ 40.3 ″  E 46 ° 51 ′ 28.6 ″  N , 10 ° 54 ′ 40.3 ″  E
Mouth height 1889  m above sea level A.
Height difference approx. 611 m
Bottom slope approx. 57 ‰
length 10.8 km
Catchment area 98 km²
Discharge at the Vent
A Eo gauge : 98.1 km².
Location: 50 m above the mouth
NNQ (03/21/1992)
MNQ 1971–2009
MQ 1971–2009
Mq 1971–2009
MHQ 1971–2009
HHQ (08/25/1987)
90 l / s
380 l / s
4.51 m³ / s
46 l / (s km²)
43.7 m³ / s
109 m³ / s
Left tributaries Vernagtbach
Communities Soelden
The Rofenache below the Hintereisferner
The mouth of the Vernagtbach in the Rofenache

The Rofenache is a glacier stream in the Ötztal Alps in Tyrol , Austria .

course

The Rofenache rises from the Hintereisferner below the Weißkugel at around 2500  m above sea level. A. You Rofental flows in a northeasterly direction, first takes Kesselwandferner Bach, shortly after the Hochjochbach and approximately 5 km from the left to the Vernagtferner and Guslarferner  fed Vernagtbach on, passed the rotting Rofen and joins after almost 11 km at Vent with the Niedertalbach to Venter Ache . In the lower reaches, the Ache has cut into the narrow Rofenschlucht gorge. Sometimes the Rofenache is viewed together with the Venter Ache as the upper reaches of the Ötztaler Ache , which is 66.5 km long.

Catchment area and water supply

The catchment area of ​​the Rofenache is around 98 km², of which (as of 1997) 37.7 km² or 39% are glaciated. In 1969 it was 42.9 km² or 44%. The highest point in the catchment area is the Wildspitze at 3768  m above sea level. A.

The mean discharge at the Vent gauge is 4.51 m³ / s, which corresponds to a very high discharge rate of 46 l / s · km². The Rofenache shows a glacial runoff regime with a strong amplitude, which is significantly influenced by the glaciers. In the winter months of February and March, the monthly mean of the discharge is below 0.5 m³ / s. Only in late spring does the discharge increase significantly and reach its peak in July and August with a monthly mean of almost 15 m³ / s, more than 30 times the winter months. In autumn the water flow drops again quickly. Especially in summer there are also strong fluctuations in the runoff during the day. The sun's rays and the high temperatures lead to a melting of the glacier ice during the day, which contributes significantly to the runoff of the Rofenache. On particularly hot days, the flow at the Vent gauge can rise by more than 40 m³ / s within a few hours.


Average monthly runoff of the Rofenache (MQ in m³ / s) at the Vent gauge,
survey period 1971–2009, source: Hydrographisches Jahrbuch 2009

The runoff of the Rofenache is also an indicator for the melting of the glaciers . The mean air temperature at the Vent measuring point has increased by 0.3 ° C per decade , and in the summer months even by 0.44 ° C per decade. In contrast, precipitation in the catchment area does not show any significant increases or decreases. The discharges measured at the Vent gauge in the summer months of June, July and August have increased by an average of 1.2 m³ / s per decade since the 1980s. Since this was probably not caused by an increase in summer precipitation, the increase in runoff can only be explained by the increased melting of the glacier ice. Model calculations, assuming further increasing temperatures, predict a significant change in the runoff regime. The summer runoff will increase due to the increased melting of the glacier ice until 2020 and in summer the monthly mean will be reached by 16 m³ / s. The runoff is then more balanced again, and there is a transition from a glacial to a nival runoff regime. According to the models, around 2050 the maximum will be reached in May with only around 6 m³ / s due to the earlier snowmelt, followed by a gradual decrease over the summer and autumn months.

The Rofener Eissee

The Rofener Eissee in 1601

In the past, the Vernagtferner, which today ends a few kilometers above the Rofental, pushed into the valley several times. He dammed the Rofenache into a lake , the Rofener Eissee , which in 1601 was 1.7 km long and had a volume of 11 million m³. When the ice dam broke, the last time in 1848 was flooding and severe damage to the entire Ötztal.

Power plant plans

Protest sign against the reservoir (2010)

In the course of the planned expansion of the Kaunertal power station by TIWAG , there were considerations to use the Rofental as an upper level storage facility for pumped storage operation with the Gepatsch storage facility . These plans envisaged a 170 m high dam wall as well as streams for the numerous glacial streams and their discharge into the Kaunertal . There was strong resistance to this, u. a. from the Austrian and German Alpine Association , who feared massive damage to the landscape and thus to mountaineering tourism. In the meantime, TIWAG has moved away from the Rofental storage facility, and water is now to be diverted from the Venter Ache below Vent.

Web links

Commons : Rofenache  - collection of images, videos and audio files

Individual evidence

  1. a b c TIRIS - Tyrolean regional planning and information system
  2. a b c Federal Ministry of Agriculture, Forestry, Environment and Water Management (ed.): Hydrographisches Jahrbuch von Österreich 2009. 117th volume. Vienna 2011, p. OG 94, PDF (12.1 MB) on bmlrt.gv.at (yearbook 2009)
  3. ^ Franz K. Zoller (Hrsg.): Alphabetical-topographical paperback of Tyrol and Vorarlberg . Innsbruck 1827, p. 216 ( book in Google book search)
  4. a b Michael Kuhn, Jakob Abermann, Marc Olefs, Andrea Fischer, Astrid Lambrecht: Glaciers in Climate Change: Current Monitoring Programs and Research on the Effects on Area Runoff in the Ötztal. In: Information sheet of the Hydrographic Service in Austria, No. 86 (2009), pp. 31–47 ( PDF; 6.1 MB )
  5. Austria's glaciers are retreating ( Memento from August 29, 2013 in the Internet Archive )
  6. ^ Ministry of Life / wasseraktiv.at: Ice & Snow - Water, Climate Change & Floods
  7. Markus Weber, Ludwig Braun, Wolfram Mauser, Monika Prasch: The significance of glacier melt for the discharge of the Danube now and in the future . In: Information sheet of the Hydrographic Service in Austria, No. 86 (2009), pp. 1–30 ( PDF; 6.1 MB )
  8. Dept. Glaciology of the Commission for Earth Measurement and Glaciology of the BAdW-Munich: Contemporary representation of the Rofener Ice Lake dammed by the Vernagtferner
  9. Tirol Atlas: Natural History Tyrol
  10. a b DAV against Kraftwerk im Rofental , tirol.orf.at of July 16, 2005
  11. ^ Peter Haßlacher: Power plant discussion: Mountaineering village Vent in great danger. In: Bergauf, 01-2006, pp. 24–25 ( PDF; 274 kB )
  12. Expansion of the Kaunertal power plant presented , tirol.orf.at of February 4, 2011
  13. Project area: Expansion of the Kaunertal power plant ( Memento from November 12, 2013 in the Internet Archive ) (TIWAG)