Sunday, 9 December 2012

Interesting conferences linked with fluvial problematics

We plan to participate on some conferences in year 2013:
  • State of Geomorphological Research in year 2013 (link):
    • international conference that is organized this time by the joint effort of geographical institutions in Brno under the auspices of the Czech Association of Geomorphologists,
    • will take place in Mikulov, Czech Republic from April 24 to 26, 2013.
  • 8th IAG International Conference on Geomorphology (link):
    • organized by the Groupe Francais de Géomorphologie (GFG) under the auspices of the International Association of Geomorphologists (IAG),
    • will take place in Paris, France, at the Cité des Sciences de la Villette from August 27 to 31, 2013.
  • Water and Environmental Dynamics (link):
    • 6th International Conference on Water Resources and Environment Research (ICWRER),
    • organised with the European sediment network SedNet,
    • will take place in Koblenz, Germany from June 3 to 7, 2013.

Paper in prepare: Complex transformation of the geomorphic regime of channels in the forefield of the Moravskoslezské Beskydy Mts: case study of the Morávka River (Czech Republic)

This paper presents a complex analysis of both the contemporary and historic development of the geomorphic regime of the transformed reach of the Morávka River in the Czech Carpathians. The assessment concentrates on the conditions and causes of the channel development of the last c. 200 years, as compared to the state of European channels, especially those of the Carpathian zone. The Morávka River pattern has undergone a rapid change in the last 50 years, namely in connection with the active channel narrowing and massive deep erosion. The original anabranching river pattern has gradually been substituted by a simple narrowed channel that incised as deep as the bedrock (see Fig. 1).

 Fig. 1: The development of the Morávka river pattern between 1.6 and 3.5 r. km in the period of 1836 – 2010; A – state on the map of the Second Military Mapping from the period of 1836-52; B – state on the map of the Third Military Mapping from 1876-78; C – state captured on the aerial image from the year 1937; D – state on the aerial image from the year 1955; E – state on the orthophoto from the year 2010.

At some parts, the original river bottom has lowered as many as 8 m in the last 40 years, which points to the incision rate of 12-24 cm per year (see Fig. 2).

Fig. 2: Cross profile at 2.31 r. km in the area of the canyon of the Morávka River with the identification of deep erosion starting in the year 1992.

These changes have been caused by a strong anthropogenic impact in the form of the river channel controlling, bank stabilising, and level, weir and valley dam constructing. Other reasons are related to land cover and land use changes. An important role in the Moravskoslezské Beskydy Mts is played by the period of the so-called Walachian colonisation of the second half of the 15th century and the 16th century characterised by deforestation, land cover degradation, accelerated runoff and gully erosion initiation. This period was replaced by the phase of reforestation in the first half of the 20th century when the stabilisation potential sedimentary material for Beskydian channels initiated along with deep river bed erosion. A great influence on the contemporary processes is also exerted by the geological predisposition of the Carpathian flysch lithology in channel bedrock. It is particularly the occurrence of claystone layers that are little resistant to water erosion. At the present time, the deficit of transportable sedimentary material along with increased transport capacity of the incised riverbed make conditions for constantly intensifying erosion processes in the Morávka channel. 

Fig. 3: A – Comparison of average incision and discharge values of selected European rivers; B – Variability in average incision rates of Carpathian rivers and remaining European rivers (including Alpine rivers); C – Variability in the discharge of Carpathian rivers and remaining European rivers (including Alpine rivers); p – result of non-parametric statistical Mann-Whitney U-test presenting the significance and insignificance of differences, the box plot shows the span of measured widths between the lower (25%) and upper quartiles. (Created based on: Kondolf et al., 2002; Lach and Wyżga, 2002; Marston et al., 1995; Martín-Vide et al., 2010; Preciso et al., 2011; Rinaldi and Simon, 1998; Rinaldi, 2003; Rovira et al., 2005; Surian and Cisotto, 2007; Surian and Rinaldi, 2003; Surian et al., 2009; Uribelarrea et al., 2003; Wyżga, 1993; Wyżga, 2001; Zawiejska and Wyżga, 2009).

  • Kondolf, G.M., Piégay, H., Landon, N., 2002. Channel response to increased and decreased bedload supply from land use change: contrast between two catchments. Geomorphology 45, 35-51.
  • Lach, J., Wyżga, B., 2002. Channel incision and flow increase of the upper Wisłoka River, southern Poland, subsequent to the reafforestation of its catchment. Earth Surface Processes and Landforms 27, 445–462.
  • Marston, R.A., Girel, J., Pautou, G., Piégay, H., Bravard, J.P., Arneson, C., 1995. Channel metamorphosis, floodplain disturbance, and vegetation development: Ain River, France. Geomorphology 13, 121–131.
  • Martín-Vide, J., Ferrer-Boix, C., Ollero, A., 2010. Incision due to gravel mining: Modeling a case study from the Gállego River, Spain. Geomorphology 117, 261–271.
  • Preciso, E., Salemi, E., Billi, P., 2011. Land use changes, torrent control works and sediment mining: effects on channel morphology and sediment flux, case study of the Reno River (Northern Italy). Hydrological processes.
  • Rinaldi, M., Simon, A., 1998. Bed-level adjustment in the Arno River, Central Italy. Geomorphology 22, 57–71.
  • Rinaldi, M., 2003. Recent channel adjustments in alluvial rivers of Tuscany, Central Italy. Earth Surface Processes and Landforms 28, 587–608.
  • Rovira, A., Batalla, R.J., Sala, M., 2005. Response of river sediment budget after historical gravel mining (the lower Tordera, NE Spain). River research and applications 21, 829–847.
  • Surian, N., Cisotto, A., 2007. Channel adjustment, bedload transport and sediment sources in a gravel-bed river, Brenta River, Italy. Earth Surface Processes and Landforms 32, 1641–1656.
  • Surian, N., Rinaldi, M., 2003. Morphological response to river engineering and management in alluvial channels in Italy. Geomorphology 50, 307–326.
  • Surian, N., 1999. Channel changes due to river regulation: the case of the Piave River, Italy. Earth Surface Processes and Landforms 24, 1135–1151.
  • Uribelarrea, D., Pérez-González, A., Benito, G., 2003. Channel changes in the Jarama and Tagus rivers (central Spain) over the past 500 years. Quaternary Science Reviews 22, 2209–2221.
  • Wyżga, B., 1993. River response to channel regulation: case study of the Raba River, Carpathians, Poland. Earth Surface Processes and Landforms 18, 541–556.
  • Wyżga, B., 2001. Impact of the channelization-induced incision of the Skawa and Wisłoka Rivers, Southern Poland, on the conditions of overbank deposition. Regulated Rivers: Research and Management 17, 85–100.
  • Zawiejska, J., Wyżga, B., 2010. Twentieth-century channel change on the Dunajec River, southern Poland: Patterns, causes and controls. Geomorphology 117, 234–246.

Sunday, 4 November 2012

Critical conditions for beginning of bedload transport in Beskydian headwater channels

Bedload transport in view of its beginning was evaluated during years 2010 and 2011 in Beskydian headwater channels, namely Malá Ráztoka and Lubina streams (Fig. 1). After Q20-25 flood event in May 2010, flood competence method was applied in nine channel-reaches (7 in Lubina Stream and 2 in Malá Ráztoka Stream), when we measured diameters of the largest transported boulders (ca. 200-400 mm) transported and stored in to fluvial accumulations during such event (Fig. 2). Also, geometry parameters and grain size distributions were obtained from the selected reaches upstream the fluvial accumulations. Movement of marked particles (18-152 mm) was evaluated during smaller discharges up to bankfull stage between November 2010 and July 2011 in channel-reaches nearby a gauging station in the Malá Ráztoka basin (Fig. 3). 

Fig. 1. Location of the studied torrents: Lubina (L) and Malá Ráztoka (MR).

 Fig. 2. Measurement of the boulder stored during May 2010 flood event in the Lubina Stream.

Fig. 3. Position of marked particles on the crest of step in step-pool channel (Malá Ráztoka).

Derived critical values (unit stream power and unit discharge) of the movement of certain grain diameters were fitted to relationships ωci=0.445di^1.06 (di in mm) and qci=0.8di^0.51 (di in m) (Fig. 4 and Fig. 5). Obtained critical values were generally lower than those coming from Alpine and Andine environments (see Lenzi et al., 2006; Mao et al., 2008). This fact may have been caused by lower bed armouring or higher sediment supply in local torrents, when compared to the magnitude of discharges in Alpine and Andine torrents. In step-pool morphology systems, the dynamics of sediment transport was higher in pools than on steps at bankfull flow (38% of grains, respectively 12% of grains, were moved), whereas the opposite was observed at lower flow.
Fig. 4. Derived critical unit stream powers from both flood competence and marked particle transport methods.

Fig. 5. Derived critical unit discharges from both flood competence and marked particle transport methods.

The results of the research were recently published in the Carpathian Journal of Earth and Environmental Sciences: link  

  • Lenzi, M.A., Mao, L., Comiti, F. (2006): When does bedload transport begin in steep boulder-bed stream? Hydrologic. Process. 20, 3517-3533.
  • Mao, L., Uyttendaele, G.P., Iroumé, A. & Lenzi, M.A., 2008. Field based analysis of sediment entrainment in two high gradient streams located in Alpine and Andine environments. Geomorphology 93, 368-383.

Saturday, 27 October 2012

Interesting conference about sediments of aquatic environment

We plan to participate in 7th conference of Sediments of streams and reservoirs (Sedimenty vodných tokov a nádrží), which will take place on 22-23th May in Bratislava. The coordinator of this event is Slovak Water Research Institute (Výzkumný ústav vodného hospodárstva), Slovak Water Management Institute ZSVTS (Slovenská vodohospodárska spoločnosť ZSVTS). One of scope covers sedimentology processes in streams and reservoirs and thus, our prepared contributions will deal with recent research in sediment fluxes and sediment transport modelling in Beskydian gravel-bed rivers and headwater streams.

Information about the conference together with the firts circular are published in Slovak language here:

Monday, 15 October 2012

Processes and Patterns in Highly Dynamic Mountain Fluvial Systems

International Field Seminar 2 - 4 June, 2012 Stará Lesná (Slovakia) - Zakopane (Poland)

Guidance Bartłomiej Wyżga, Joanna Zawiejska and Milan Lehotský.

In June from 2nd to 4th took place meeting of fluvial geomorphologists from Poland, Slovakia, Czech Republic, Romania and United Kingdom of Great Britain. Main aim was presentation of researches and recent environmental problems of Carpathian mountain streams. Prof. Bartłomiej Wyżga, dr. Joanna Zawiejska and dr. Milan Lehotský were main guidance.

 Fig. 1: Belá River - site Vavrišovo, impact of a small hydropower plant construction on the river channel evolution (Photo by: Galia, T.) 

Fig. 2: Czarny Dunajec River - site Wróblówka - environment-friendly reduction of flood risk in a mountain river (Photo by: Škarpich, V.)

Fig. 3: Raba River - erodible corridor as a restoration technique for mountain rivers (Photo by: Galia, T.).

Report (in czech) about field seminar in bulletin "Information of The Czech Geographic Society" here.