We continue with the monitoring of bed particles marked by pit-tags, which have been installed into stream beds of two contrast small streams (check-dam impacted and close-to-nature pool-riffle stream) with similar catchment areas. The monitoring covered one bankfull event and several close-to-bankfull discharge events in following months. After ca. 21-month period, up to 350 m transport distance was measured for tagged particles in the check-dam managed stream; some of grains passed through four check dams. Similar transport distance (up to 300 m) was obtained in the pool-riffle stream. However, there were large differences in recovery rates of pit-tag-marked grains. We reached up to 65% recovery rate in the check-dam managed streams, but only 20-25% recovery rate prevailled in the pool-riffle stream. This notably low recovery rate is likely caused by higher morphodynamics of the pool-riffle stream, which caused frequent burying of the marked grains into gravel-bed deposits during sediment transport-effective discharges. We are planning to continue this monitoring also in the following year; this will also include a development of rating curves for both studied streams, which will allow us to create direct relations between the critical discharge and transported distance (or size) of tagged particles.
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| Monitored check-dam impacted stream |
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| Monitored pool-riffle stream |
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