Rännan
Rännan
 

 

Cross section
Cross section
 
 
 Rännan, the hydrological station measuring the discharge from the Tarfala drainage basin (photo and illustration: Peter Jansson)
The Rännan hydrological station is equipped with a Geokon Model 4580vibrating wire pressure transducer logged by a Campbell Scientific CR-10Xdata logger. The sensor is fixed in the observation pipe using a brass rod which is clamped at the top of the pipe to prevent vertical shifts of the sensor as sediment is pushed into pipe. A tipping bucket rain gauage and a Pt100 temperature probe i a Gill shield is also permanently mounted at the site. Data is logged throughout the year.
Pressure transducer
Pressure transducer
 

 

The pressure transducer mounted on the fixing rod (designed and mfg by Torbjörn Karlin; photo: Peter Jansson) 

The top
The top
 
 
 
 
 
   

 

 

 
Upstream of Rännan
 

 

 

A look upstream of Rännan at low discharge (Sep. 2005, photo: Peter Jansson)
A short movie (AVI-format) showing fall flow in Rännan:
The Lillsjön gauging station
The Lillsjön gauging station is equipped with the same sensor and data logging equipment as Rännan (Geokon model 4580 and Campbell Sci CR-10X). The station is only in operation during the summer season (July-mid-September) since the out let from lake Lillsjön is largely frozen to the bed during winter. A Pt100 temperature probe in a Gill shield is also in operation during the same period. The Lillsjön station is located in a slightly modified natural outlet of a lake dammed by the terminal moraine complex of Storglaciären.
 
The Lillsjön hydrological station -upstream
The Lillsjön hydrological station -upstream
 
The Lillsjön hydrological station seen from up-stream (photo: Peter Jansson)

 

 
The Lillsjön hydrological station -downstream
The Lillsjön hydrological station -downstream
 
 
The Lillsjön hydrological station seen from down-stream. Tarfala Research Station in the background (photo: Peter Jansson)