River Surveys To Improve Shallow Water Navigation
The pusher-tug Strekov was converted to a survey vessel for gathering data along the River Elbe.
Vars Brno a.s. in the Czech Republic and the state enterprise Povodi Labe surveyed the River Elbe for data to help vessel skippers with navigation planning and vessel-loading decisions, based on actual depths.
Vars used its 250 kHz version of the Geo-Swath Plus combined multi-beam and side scan system. It gathered high-resolution depth data over a wide angle of coverage in the shallow waters.
Initial surveys on a 42 kilometers stretch of the River Elbe between the German border and the Czech city of Ustí was carried out in extremely shallow water with depths ranging from 1 to 6 meters. There, the water level also varies depending upon fl ow rate and local rainfall. Secure navigation depths are constantly changing, often during the course of a single day, based on the volume of rain encountered. Furthermore the navigable channel is often not wider than 40 meters, which results in very high currents. Accidents happen frequently in the area, often caused by groundings.
The survey results will generate depth data for safer navigation and object detection. The data is imported as the default depth reading to the inland electronic navigational charts (IENC). The measurements are also used to identify areas for dredging and to target anomalous soundings for further investigation.
Detailed digital terrain models of the river bottom have recently uncovered some hidden secrets. A number of objects, possibly hazardous to navigation and undetected previously, have been removed from the channel. The data here shows the bathymetric image of a small vessel, which was subsequently pulled from the river.