Thursday, 23 June 2016

Workshop “Methods of detailed analysis in fluvial geomorphology” was realized

21st – 22nd of June, 2016

Dr. Václav Škarpich (member of Czech-Rivers group of the fluvial section of the Department of Physical Geography and Geoecology, University of Ostrava)
Dr. Jan Blöthe (University of Bonn)
Dr. Veronika Kapustová (University of Ostrava)

Many aspects of fluvial processes and morphology may be measured to help to assess conditions of rivers. Modern research methods in fluvial geomorphology provide an integrated approach to the guidance for researchers to answer questions on river behaviour. The workshop “Methods of detailed analysis in fluvial geomorphology” was addressed to those students and young researchers who are dealing with river systems and hydrology. General aim of the workshop was a demonstration of modern methods and their application in fluvial-geomorphic research. The workshop was focused on practical presentation of basic methods for data collection in the field and subsequent analysis of obtained data, e.g., using BAGS (Bedload Assessment for Gravel-Bed Streams) software or Sedimetrics Digital Gravelometer. We showed how to obtain high-resolution remote sensing data using UAV technology and how to digitally reconstruct terrain and objects using Structure from Motion technique. One of the lecturers was Dr. Jan Blöthe from the University of Bonn, staying at our Department via Erasmus+ teaching mobility.

Photo of the Bečva R. channel obtained by UAV technology

Photo of the Bečva R. channel obtained by UAV technology

Dr. Jan Blöthe and students are operating UAV technology

Measuring of flow velocities by students

Tuesday, 21 June 2016

River wood in Beskydian headwaters

The first results from the research of river wood in Mazácky Gruník natural monument (protected since 1950s) were presented at EGU conference in Vienna (April 2016) - see the poster below. Field works including dating of key logs in three headwater channels have been finished in the middle of June. Preliminary results show, that observed volumes of river wood are probably not at the 'natural' level before first human interventions (including forest management with removal of logs from channels) and some longer recovery time for development of log jams is needed. However, the research in this topic will continue in the month of July, when there is planned measurement and tagging of large wood in two meandering channel-reaches of the Odra River. 
Poster from EGU 2016 conference.

Saturday, 18 June 2016

Short report from a field trip to Swiss torrents

Colleagues K. Šilhán and R. Tichavský from and T. Galia participated the field trip to typical check-dam managed stream and the experimental watershed of the Erlenbach Stream, both located in the pre-alpine area of Switzerland. Flood events during past decades in the Gürbe Torrent (Bern canton) caused some serious damages in the forefield villages due to massive bedload transport and deposition of coarse material. A reconstruction of grade-control structures (mainly classic check-dams) took place in 2007-2009, when the first control structures were implemented in the middle of 19th century.

Check-dams in the Gürbe Torrent

Measurements of bedload transport in the Erlenbach Stream has been performed for 30 years. Flow discharge is measured and sediment is collected in a retention basin (capacity ca. 2000 m3). Sediment transport has been also continuously monitored with piezoelectric bedload impact and geophone sensors since 1986 and by an automatic system with special baskets to obtain bedload samples. In this watershed, other experiments as evaulation of water chemistry or slope-channel coupling processes take place. The rest of stay in Switzerland was dedicated to meeting with colleagues from also including discussions about river wood research in study sites in the Czech Republic (the Mazák Stream, the Odra River).
Bedload transport measurements in the Erlenbach Stream