Original paper
The Pebble Transmitter System (PETS): first results of a technique for studying coarse material erosion, transport and deposition
Ergenzinger, Peter; Schmidt, Karl-Heinz; Busskamp, Ralf
Zeitschrift für Geomorphologie Volume 33 Issue 4 (1989), p. 503 - 508
9 references
published: Dec 27, 1989
ArtNo. ESP022003304010, Price: 29.00 €
Abstract
There is a growing awareness of the need for new measuring techniques of coarse material bed load transport under natural conditions. In the last few decades a variety of new samplers have been developed, but in each case adequate results were achieved only under very restrictive conditions because of the limited size of the samplers; the coarser the material the less reliable were the results. Tracer techniques mainly consisted of painting pebbles or cobbles. Again, the larger the river the less reliable were these attempts, since the recovery rates were often less than 10 percent. Promising efforts to tag the material by radioactive tracers involved some radiation hazards and do not comply with the present legislation on environmental protection. In this situation the most successful measurements of coarse bed load transport have been made at a few small rivers using expensive vortex-tube or conveyor-celt samplers (Klingeman & Milhous 1970, Tacconi 1977, Emmett 1979). The introduction of the magnetic tracer technique both for natural magnetic material and cobbles with implanted magnetic cores (Ergenzinger & Conrady 1982) has offered new and cheaper possibilities. Either the amount of tracered material was detected after transport by a special magnetometer (Hassan et al. 1984), or the transit of the tracered material across a coil system was measured by means of the Faraday principle (Ergenzinger & Custer 1983, Reid, Brayshaw & Frostick 1984). Using this procedure, detailed studies of the time dependency of transport are possible. These techniques are especially appropriate at sites containing naturally magnetic pebbles. Spieker & Ergenzinger (1989) showed that even the grain size of the transported material can be determined within a certain probability range. However, the observation of individual particles with specific characteristics of weight, pebble morphometry and density under given hydraulic conditions is not possible. The Pebble Transmitter System (PETS) which involves pebbles containing transmitters has been developed to study the more detailed questions of entrainment, travel length and velocity, as well as of sites and conditions of deposition of individual particles. The new technique is an active tracer system and was tested at the Lainbach station in Bavaria in 19881. The development and the investigations are funded by the Deutsche Forschungsgemeinschaft (German National Science Foundation).
Keywords
load transport • magnetometer • pebbles • radioactive tracer • vortex-tube • conveyor-belt • Pebble Transmitter System • PETS • German National Science Foundation